4BE3.5 U4 C4 Obj 2 EMH

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

EASY Why is it important to ensure the scanner tube has adequate air supply?

To increase the life span of the scanner

To improve the accuracy of the scanner

To keep the scanner tube clean

To prevent the scanner tube from overheating (correct)

What is the recommended replacement period for flame rods and scanners according to ASME CSD-1?

Every 6 months

Every 10 years

Every year (correct)

Every 5 years

What is the purpose of the low gas pressure cut-off switch?

To regulate the airflow to the burner

To shut off the boiler in case of low gas pressure (correct)

To monitor the temperature of the boiler

To shut off the boiler in case of high gas pressure

How often should the combustion air proving switch be tested according to ASME CSD-1?

Monthly Signup and view all the answers

Why is it important to test safety and safety relief valves?

To ensure the safety of the boiler and its operators Signup and view all the answers

What is the purpose of the manual try lever test?

To determine the freedom of valve movement Signup and view all the answers

What is the primary objective of performing regularly scheduled checks on safety devices in a boiler plant?

To ensure a safe and reliable boiler plant Signup and view all the answers

What is the recommended frequency for checking the boiler flame failure detection systems according to ASME CSD-1?

Weekly Signup and view all the answers

What is the recommended frequency of safety valve checks according to ASME BPVC VI and VII?

Outlined in Table 1 Signup and view all the answers

Why should the scanner lens be cleaned at regular intervals?

To keep the scanner lens free from obstructions Signup and view all the answers

Why must safety checks be scheduled for a specific time?

To avoid affecting the operation of the facility Signup and view all the answers

What is required to test the flame failure device on a boiler?

Simulating a flame failure condition Signup and view all the answers

What is the life expectancy of an ultraviolet flame scanner?

40,000 hours Signup and view all the answers

What should be checked regularly for buildup of deposits?

Flame rods Signup and view all the answers

What document describes the recommended procedure for testing flame safeguard devices?

ASME BPVC VI Signup and view all the answers

What is the recommended time for the safety shut-off valve to close when testing a gas burner with a thermocouple or thermopile flame sensor?

The time recommended by the valve manufacturer Signup and view all the answers

What is the recommended time for the safety shut-off valve to close when testing a gas burner with an electronic flame rod and continuous pilot?

Less than 4 seconds Signup and view all the answers

What should be followed when testing various devices?

Manufacturer testing instructions Signup and view all the answers

What is the first step in relighting a pilot according to the burner manufacturer procedures?

Relight the pilot Signup and view all the answers

How long should it take for the safety shut-off valve to close in a gas burner with electronic flame rod and interrupted pilot?

Four seconds or less Signup and view all the answers

What happens if the pilot safety shut-off valve does not close at the end of the pilot trial-for-ignition period?

The boiler will shut down and require manual reset Signup and view all the answers

Why is the main burner test firing valve closed in the procedure for checking main flame failure response?

To prevent the main burner from igniting Signup and view all the answers

What is the purpose of the post-purge period after a flame failure?

To remove any unburned fuel Signup and view all the answers

What type of burners may recycle in order to attempt to relight the burner after a flame failure?

Smaller burners Signup and view all the answers

What is the purpose of the pilot burner test firing valve?

To shut off the pilot burner Signup and view all the answers

What type of alarm often accompanies a flame failure?

Audio-visual alarm Signup and view all the answers

What is the purpose of blowing out accumulated dust in the programmed combustion control?

To perform routine maintenance Signup and view all the answers

What happens when the pilot safety shut-off valve closes during the pilot trial-for-ignition period?

No flame will be detected Signup and view all the answers

What is the minimum boiler pressure required to perform a try lever test?

35 kPa Signup and view all the answers

Why should all personnel be cleared from the area near the safety valve before conducting a manual try lever test?

To prevent steam from overflowing into the operating area Signup and view all the answers

What is the purpose of a pop test?

To identify defective valves Signup and view all the answers

When should a pop test be performed?

When taking a boiler off-line for annual maintenance Signup and view all the answers

What should be done before performing a pop test?

Check the set point and blowdown of the safety valve Signup and view all the answers

Why should the operating control and high limit control be bypassed during a pop test?

To prevent the boiler from shutting down Signup and view all the answers

What should be done when the safety valve fails to open at the required pressure?

Shut off the burner Signup and view all the answers

Why should the try lever test be performed after a pop test?

To ensure the valve is not seized Signup and view all the answers

What should be recorded in the log book after a pop test?

The opening and reseating pressures Signup and view all the answers

Why should the boiler steam outlet and feedwater supply valves be closed during a pop test?

To isolate the boiler system Signup and view all the answers

What is the primary purpose of the high temperature cut-off control in a hot water boiler?

To shut down the firing equipment when the water temperature reaches a set point Signup and view all the answers

What is the maximum allowable water temperature for hot water heating boilers according to ASME BPVC IV?

120°C Signup and view all the answers

Why should the cut-off temperature of the high temperature cut-off control be set above the cut-off setting of the operating control on hot water boilers?

To provide an additional layer of safety Signup and view all the answers

What should be done after the high temperature cut-off control has operated and shut down the firing equipment?

The power should be disconnected and the test lead removed Signup and view all the answers

What is the physical limitation of most high temperature cut-off controls?

They are limited to temperature settings lower than 115°C Signup and view all the answers

What is the maximum acceptable pressure during an accumulation test for a boiler with a MAWP of 1380 kPa and a safety valve set to 1310 kPa?

1389 kPa Signup and view all the answers

What is the primary purpose of the safety valve equipment in a boiler?

To prevent excess pressure during operation Signup and view all the answers

What is the recommended frequency for performing the float chamber blowdown test on a heating boiler?

Weekly Signup and view all the answers

What is the purpose of rapidly draining the float chamber during a low water cut-off test?

To discharge sediment from the base of the float chamber Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

Remove the boiler from service until the low water cut-off is repaired or replaced Signup and view all the answers

What is the recommended frequency for performing the slow drain test on a heating boiler?

Semi-annually Signup and view all the answers

What should be checked closely during low water cut-off tests?

The boiler's water level Signup and view all the answers

What happens when the float chamber drain valve is closed after a float chamber blowdown test?

The water level in the float chamber quickly returns to normal Signup and view all the answers

What is an alternative to the slow drain test for low water cut-off testing?

Isolating the feedwater and allowing the boiler to steam off water Signup and view all the answers

What should be done after testing the low water cut-off?

Return all valves to their normal operating positions Signup and view all the answers

What should be done if the valve still fails to open after the pop test?

The boiler must be removed from service Signup and view all the answers

What is the maximum tolerance for the set pressure of safety valves according to ASME BPVC IV, Part HG-401.1?

2 psi (15 kPa) Signup and view all the answers

What should be done if the safety valve does not open at 17 psi (115 kPa)?

Shut off the burner and dissipate the steam to the system Signup and view all the answers

What is the minimum blowdown required for safety valves according to ASME BPVC I, Part PG-72.1?

2 psi (15 kPa) Signup and view all the answers

What is the purpose of an accumulation test?

To determine the safety valve capacity Signup and view all the answers

What is the maximum allowable pressure rise above the highest pressure at which any valve is set according to ASME BPVC I Part PG-67.2?

6% above the highest pressure at which any valve is set Signup and view all the answers

What is the reason for not performing an accumulation test on a boiler with a superheater?

The method is not applicable to boilers with superheaters Signup and view all the answers

What should be done to the boiler before performing an accumulation test?

The boiler should be shut down and the pressure limit controls bypassed Signup and view all the answers

What happens during an accumulation test?

The boiler pressure will increase until the energy released by the safety valve equals the energy input to the boiler water Signup and view all the answers

What is the requirement for safety valves according to ASME BPVC IV, Part HG-400.1?

The safety valve must be adjusted to discharge at a pressure not to exceed 15 psi (100 kPa) Signup and view all the answers

What is the purpose of the feedwater control in a steam boiler?

To control the flow of make-up water to the boiler Signup and view all the answers

What is the recommended frequency for inspecting and maintaining the water level controls in a steam boiler?

Every 12 months Signup and view all the answers

What is the purpose of the operating limit switch in a steam boiler?

To observe the cut-in and cut-off pressures of the boiler Signup and view all the answers

What is the purpose of the high-pressure cut-off control in a steam boiler?

To shut down the boiler in case of high steam pressure Signup and view all the answers

What should be done to the high-pressure cut-off control during testing?

It should be disconnected from the power supply Signup and view all the answers

What is the recommended procedure for testing the high-pressure cut-off control in a steam boiler?

Disconnect the power to the boiler controls and place a test lead across the terminals of the operating cut-off control Signup and view all the answers

What is the purpose of marking the levels at which the feedwater system starts and stops on the gauge glass?

To identify potential level control problems Signup and view all the answers

What should be checked during the annual maintenance of the water level controls in a steam boiler?

All parts of the controls, including electrical contacts, wiring, and connecting lines Signup and view all the answers

What should be done to the make-up valve during testing?

It should be checked for tight closure Signup and view all the answers

What is the purpose of the combined feeder/cut-off control in a steam boiler?

To feed make-up water to the boiler Signup and view all the answers

What is the purpose of the flow switch in a boiler?

To ensure the boiler does not fire unless there is adequate circulation Signup and view all the answers

How should the low water cut-off be tested in a hot water boiler?

Using a special combination test and check valve Signup and view all the answers

What is the recommended frequency for testing the low water cut-off in a hot water boiler?

Monthly Signup and view all the answers

What should be observed during routine boiler monitoring?

The cut-in and cut-off temperatures of the operating limit switch Signup and view all the answers

What is necessary to test the high temperature cut-off?

Disconnecting the power to the boiler controls Signup and view all the answers

Why is it necessary to test the flow switch?

To prevent overheating of the heat transfer surfaces Signup and view all the answers

What is the purpose of the special combination test and check valve?

To test the low water cut-off Signup and view all the answers

What should be done with a defective low water cut-off?

Repair or replace it at the end of the heating season Signup and view all the answers

What is the purpose of the operating limit switch?

To control the boiler's temperature Signup and view all the answers

Why is it important to follow the manufacturer's instructions for the low water cut-off?

To ensure the low water cut-off functions properly Signup and view all the answers

What should be done after the pilot burner is lit according to the manufacturer's procedures?

Light the main burner by slowly opening the main burner test firing valve. Signup and view all the answers

What is the purpose of closing the main burner test firing valve when checking the main flame failure response?

To simulate a main flame failure. Signup and view all the answers

What happens if the pilot safety shut-off valve does not close at the end of the pilot trial-for-ignition period?

The boiler will shut down and lockout. Signup and view all the answers

What is the purpose of the post-purge period after a flame failure?

To vent any unburned fuel from the burner. Signup and view all the answers

What type of alarm often accompanies a flame failure?

Audio-visual alarm. Signup and view all the answers

MEDIUM What is the recommended time for the safety shut-off valve to close when testing a gas burner with an electronic flame rod and interrupted pilot?

4 seconds or less. Signup and view all the answers

What should be done to the scanner tube according to maintenance procedures?

Blow out accumulated dust occasionally. Signup and view all the answers

What is the primary purpose of the programmed combustion control?

To monitor and respond to flame failures. Signup and view all the answers

What happens during a safety shut-down/lockout?

The boiler undergoes a post-purge. Signup and view all the answers

Why is occasional blowing out of accumulated dust necessary in the programmed combustion control?

To ensure proper operation and prevent malfunction. Signup and view all the answers

What happens to an ultraviolet flame scanner as it ages?

It fails to discriminate between flame and light of different frequency Signup and view all the answers

What is the recommended frequency for testing the low gas pressure cut-off switch?

Monthly Signup and view all the answers

What is the purpose of the combustion air proving switch?

To prove combustion air flow Signup and view all the answers

What is the primary objective of performing regularly scheduled checks on safety devices in a boiler plant?

To ensure safe operation of the boiler Signup and view all the answers

What is the recommended frequency for performing a manual try lever test on a safety valve?

Prior to performing a pop or accumulation test Signup and view all the answers

What happens if the scanner fires excessively when exposed to ambient light?

It must be replaced Signup and view all the answers

What is the purpose of the accumulator test on a safety valve?

To determine the relieving capacity of the valve Signup and view all the answers

Why should the scanner lens be cleaned at regular intervals?

To ensure proper operation of the scanner Signup and view all the answers

What is the recommended frequency for replacing flame rods and scanners?

Annually Signup and view all the answers

What happens when the safety shut-off valves close during a test of the low gas pressure cut-off switch?

The boiler shuts down Signup and view all the answers

What is the maximum allowable pressure increase during an accumulation test for a boiler?

6% above the highest pressure at which any valve is set Signup and view all the answers

What is the minimum blowdown required for safety valves according to ASME BPVC I, Part PG-72.1?

2 psi (15 kPa) or 2% of the set pressure, whichever is greater Signup and view all the answers

What is the purpose of an accumulation test?

To verify if the installed valve capacity is sufficient Signup and view all the answers

What should be done if the safety valve does not open in the 13 to 17 psi range (85 to 115 kPa) during a pop test?

Replace the faulty safety valve Signup and view all the answers

What is the set pressure tolerance for safety valves according to ASME BPVC VI, Part HG-401.1?

Plus or minus 2 psi (15 kPa) Signup and view all the answers

What is the purpose of a pop test?

To test the safety valve's performance against the ASME BPVC performance criteria Signup and view all the answers

What should be done before performing an accumulation test?

All of the above Signup and view all the answers

What is the primary purpose of the safety valve equipment in a boiler?

To prevent an excess pressure beyond that specified in PG-67.2 Signup and view all the answers

What is the minimum boiler pressure required to perform a try lever test?

35 kPa Signup and view all the answers

Why should all personnel be cleared from the area near the safety valve before conducting a manual try lever test?

To prevent injury from steam overflow Signup and view all the answers

What happens during an accumulation test?

The boiler pressure rises until the energy released by the safety valve equals the energy input to the boiler water Signup and view all the answers

What is the purpose of a pop test?

To test the safety valve's set point Signup and view all the answers

What is the tolerance for the set pressure of safety valves according to ASME BPVC IV, Part HG-400.1?

Plus or minus 2 psi (15 kPa) Signup and view all the answers

When should a pop test be performed?

During annual maintenance Signup and view all the answers

What should be done before performing a pop test?

Check the set point and blowdown of the safety valve Signup and view all the answers

Why should the operating control and high limit control be bypassed during a pop test?

To ensure the safety valve operates correctly Signup and view all the answers

What should be recorded in the log book after a pop test?

The opening and reseating pressures Signup and view all the answers

Why should the boiler steam outlet and feedwater supply valves be closed during a pop test?

To prevent steam loss Signup and view all the answers

What should be done when the safety valve fails to open at the required pressure?

Shut off the burner Signup and view all the answers

Why should the try lever test be performed after a pop test?

To ensure the valve is free to move Signup and view all the answers

What is the primary purpose of the safety valve equipment in a boiler?

To prevent an excess pressure beyond the maximum allowable working pressure Signup and view all the answers

What is the recommended frequency for performing the float chamber blowdown test on a heating boiler?

Weekly Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

Remove the boiler from service until the low water cut-off is repaired or replaced Signup and view all the answers

What is the maximum acceptable pressure during an accumulation test for a boiler with a MAWP of 1380 kPa and a safety valve set to 1310 kPa?

1389 kPa Signup and view all the answers

What is the purpose of rapidly draining the float chamber during a low water cut-off test?

To discharge sediment from the base of the float chamber Signup and view all the answers

What should be monitored closely during low water cut-off tests?

Water level in the gauge glass Signup and view all the answers

What is the recommended frequency for performing the slow drain test on a heating boiler?

Semi-annually Signup and view all the answers

What is the primary purpose of the low water cut-off mechanism?

To prevent the boiler from operating with low water level Signup and view all the answers

What should be done after testing the low water cut-off mechanism?

Reset the low water cut-off mechanism Signup and view all the answers

What is the purpose of isolating the feedwater connection to the boiler during a low water cut-off test?

To simulate a low water level condition Signup and view all the answers

What is the purpose of marking the levels at which the feedwater system starts and stops on the gauge glass?

To verify the operation of the pump or feedwater valve Signup and view all the answers

What should be checked annually by qualified personnel?

Low water cut-offs, pump controls, and water feeders Signup and view all the answers

What should be done if the make-up valve leaks?

Repair the valve Signup and view all the answers

How is the high-pressure cut-off control tested?

By disconnecting the power to the boiler controls Signup and view all the answers

What is the purpose of the high-pressure cut-off control?

To shut down the firing equipment at high pressure Signup and view all the answers

Why should the connecting lines to the boiler be inspected?

To check for sediment and scale Signup and view all the answers

What should be done with the wiring during annual maintenance?

Check the insulation for deterioration Signup and view all the answers

What should be checked for cleanliness?

The electrical contacts Signup and view all the answers

What should be done with the bellows and float?

Check the soldered joints Signup and view all the answers

What is the purpose of the operating limit switch?

To control the boiler firing rate Signup and view all the answers

Why should the cut-off temperature of the high temperature cut-off control be set above the cut-off setting of the operating control on hot water boilers?

To allow for a safety margin in case the operating control fails Signup and view all the answers

What is the maximum allowable water temperature for hot water heating boilers according to ASME BPVC IV?

120°C Signup and view all the answers

What should be done after the high temperature cut-off control has operated and shut down the firing equipment?

Manually reset the high temperature cut-off Signup and view all the answers

What is the physical limitation of most high temperature cut-off controls?

Temperature settings above 115°C Signup and view all the answers

What is the primary purpose of the high temperature cut-off control in a hot water boiler?

To shut down the boiler in case of overheating Signup and view all the answers

What is the primary purpose of a flow switch in a copper tubular and copper fin-tube boiler?

To ensure the boiler does not fire unless there is adequate water circulation Signup and view all the answers

Why can't the low water cut-off be tested with the boiler in service?

Because it would drain the entire system Signup and view all the answers

What is the recommended frequency for testing the low water cut-off in hot water heating boilers?

Monthly Signup and view all the answers

What is the purpose of special combination test and check valves in low water cut-off systems?

To prevent the system from draining during testing Signup and view all the answers

Why is it important to test the operating limit switch during routine boiler monitoring?

To ensure the boiler is operating within the recommended temperature range Signup and view all the answers

What is the first step in testing the high temperature cut-off?

Disconnect the power to the boiler controls Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

Repair or replace the low water cut-off Signup and view all the answers

Why is it important to test the flow switch in a copper tubular and copper fin-tube boiler?

To prevent the boiler from overheating Signup and view all the answers

What is the purpose of the operating limit switch in a hot water boiler?

To monitor the boiler's temperature Signup and view all the answers

Why should the high temperature cut-off control be set above the cut-off setting of the operating control on hot water boilers?

To prevent the boiler from overheating Signup and view all the answers

What is the primary purpose of performing regularly scheduled checks on safety devices in a boiler plant?

To ensure a safe and reliable boiler plant Signup and view all the answers

What document recommends a weekly check of the boiler flame failure detection systems?

ASME CSD-1 Signup and view all the answers

What is necessary to simulate when testing the flame failure device on a boiler?

A flame failure condition Signup and view all the answers

What should be consulted when testing various devices on a boiler?

Manufacturer testing instructions Signup and view all the answers

What is the recommended procedure for testing flame safeguard devices described in?

ASME BPVC VI Signup and view all the answers

What is the purpose of closing the main burner test firing valve when testing a gas burner with a thermocouple or thermopile flame sensor?

To test the safety shut-off valve Signup and view all the answers

What is the maximum time allowed for the safety shut-off valve to close when testing a gas burner with an electronic flame rod and continuous pilot?

4 seconds Signup and view all the answers

Why must safety checks be scheduled for a specific time?

To avoid interference with facility operations Signup and view all the answers

What is the primary purpose of the post-purge period after a flame failure?

To remove any unburned fuel from the combustion chamber Signup and view all the answers

What happens if the pilot safety shut-off valve does not close at the end of the pilot trial-for-ignition period?

The burner will undergo a post-purge and safety shut-down/lockout Signup and view all the answers

Which type of burners may recycle in order to attempt to relight the burner after a flame failure?

Some smaller burners Signup and view all the answers

What is the purpose of blowing out accumulated dust in the programmed combustion control?

To maintain the accuracy of the combustion control Signup and view all the answers

What type of alarm often accompanies a flame failure?

Audio-visual alarm Signup and view all the answers

What is the recommended time for the safety shut-off valve to close when testing a gas burner with electronic flame rod and interrupted pilot?

Less than 4 seconds Signup and view all the answers

Why is the main burner test firing valve closed in the procedure for checking main flame failure response?

To simulate a main flame failure Signup and view all the answers

What happens when the pilot safety shut-off valve closes during the pilot trial-for-ignition period?

The burner undergoes a post-purge and safety shut-down/lockout Signup and view all the answers

What is the purpose of the pilot burner test firing valve?

To simulate a pilot flame failure Signup and view all the answers

What is the primary purpose of checking the pilot flame failure response?

To ensure the safe operation of the burner Signup and view all the answers

What is the primary reason why ultraviolet flame scanners fail to discriminate between the light given off by a flame and light of lower intensity and different frequency as they age?

Increased sensitivity to ambient light Signup and view all the answers

What is the recommended testing frequency for the low gas pressure cut-off switch according to ASME CSD-1?

Monthly Signup and view all the answers

Why is it essential to perform a manual try lever test prior to performing a pop or accumulation test on safety and safety relief valves?

To ensure the valve is free to operate under pressure Signup and view all the answers

What is the primary purpose of the combustion air proving switch?

To prove combustion air flow Signup and view all the answers

What is the minimum boiler pressure required to perform a try lever test?

35 kPa Signup and view all the answers

Why should all personnel be cleared from the area near the safety valve before conducting a manual try lever test?

To prevent injury from steam overflow Signup and view all the answers

Why should flame rods be checked regularly for buildup of deposits such as carbon?

To ensure proper flame detection Signup and view all the answers

What is the purpose of a pop test?

To check the safety valve's opening and closing pressures Signup and view all the answers

What is the primary purpose of the high gas pressure cut-off switch?

To prevent damage from high gas pressure Signup and view all the answers

Why should the operating control and high limit control be bypassed during a pop test?

To prevent the boiler from shutting down Signup and view all the answers

Why is it essential to ensure the scanner tube has adequate air supply?

To prevent overheating of the scanner Signup and view all the answers

What should be done when the safety valve fails to open at the required pressure during a pop test?

Shut off the burner and slowly release the steam pressure Signup and view all the answers

What is the purpose of the accumulation test for safety and safety relief valves?

To determine the valve's relieving capacity Signup and view all the answers

Why is it essential to perform annual pop tests on safety and safety relief valves?

To discover problems with the safety valve Signup and view all the answers

Why should the try lever test be performed after a pop test?

To ensure the safety valve is free to move Signup and view all the answers

What should be recorded in the log book after a pop test?

The opening and closing pressures of the safety valve Signup and view all the answers

What is the primary purpose of the manual try lever test for safety and safety relief valves?

To ensure the valve is free to operate under pressure Signup and view all the answers

Why should the boiler steam outlet and feedwater supply valves be closed during a pop test?

To ensure the safety valve operates correctly Signup and view all the answers

What should be done before performing a pop test?

Check the set point and blowdown of the safety valve Signup and view all the answers

When should a pop test be performed?

During annual maintenance Signup and view all the answers

What is the minimum pressure range at which a safety valve should open according to ASME BPVC IV, Part HG-400.1?

13 to 17 psi Signup and view all the answers

What is the maximum allowable pressure during an accumulation test for a boiler with a MAWP of 2000 kPa and a safety valve set to 1900 kPa?

2020 kPa Signup and view all the answers

What is the purpose of the controlled blowdown of a safety valve according to ASME BPVC IV, Part HG-401.1(e)?

To allow the valve to stay open until the pressure drops sufficiently Signup and view all the answers

What is the set pressure tolerance plus or minus for safety valves according to ASME BPVC VI, Part HG-401.1?

2 psi Signup and view all the answers

What is the minimum blowdown required for safety valves according to ASME BPVC I, Part PG-72.1?

2 psi Signup and view all the answers

What happens if the safety valve does not open at the required pressure during a pop test?

The valve is replaced Signup and view all the answers

What is the purpose of an accumulation test?

To verify the installed valve capacity is sufficient Signup and view all the answers

What should be done before performing an accumulation test?

The high-pressure cut-off test and pop test need to be completed Signup and view all the answers

What is the primary purpose of safety valve equipment in a boiler according to ASME BPVC I Appendix A-46.1?

To prevent the boiler from overpressurizing Signup and view all the answers

What is the maximum allowable pressure rise above the highest pressure at which any valve is set during an accumulation test according to ASME BPVC I, Part PG-67.2?

6% Signup and view all the answers

What is the primary purpose of the flow switch near the outlet of a copper tubular or fin-tube boiler?

To prevent overheating of the heat transfer surfaces Signup and view all the answers

How should the flow switch be tested?

By closing the boiler outlet valve and observing the burner Signup and view all the answers

What is the purpose of the special combination test and check valves in a low water cut-off float chamber?

To prevent the system from draining during testing Signup and view all the answers

How often should the low water cut-off be tested in a hot water heating boiler?

Monthly Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

Repair or replace the device at the end of the heating season Signup and view all the answers

Why is it important to test the operating limit switch?

To ensure the boiler operates within the expected temperature range Signup and view all the answers

How is the high temperature cut-off control typically tested?

By disconnecting the power to the boiler controls Signup and view all the answers

What is the primary purpose of the high temperature cut-off control in a hot water boiler?

To prevent overheating of the heat transfer surfaces Signup and view all the answers

Why should the cut-off temperature of the high temperature cut-off control be set above the cut-off setting of the operating control?

To prevent overheating of the heat transfer surfaces Signup and view all the answers

What should be done after the high temperature cut-off control has operated and shut down the firing equipment?

Investigate and correct the cause of the high temperature condition Signup and view all the answers

What is the primary purpose of the high temperature cut-off control in a hot water boiler?

To prevent the boiler from overheating and causing damage Signup and view all the answers

What should be done after the high temperature cut-off control has operated and shut down the firing equipment?

The power should be disconnected and the test lead removed Signup and view all the answers

What is the maximum allowable water temperature for hot water heating boilers according to ASME BPVC IV?

120°C Signup and view all the answers

Why should the cut-off temperature of the high temperature cut-off control be set above the cut-off setting of the operating control on hot water boilers?

To prevent the boiler from overheating and causing damage Signup and view all the answers

What is the physical limitation of most high temperature cut-off controls?

They can only be set to a maximum temperature of 115°C Signup and view all the answers

What is the primary objective of the safety valve equipment in a boiler?

To prevent an excess pressure beyond that specified in HG-400.1(f) and HG-400.2(f). Signup and view all the answers

What is the recommended frequency for performing the float chamber blowdown test on a heating boiler?

Weekly Signup and view all the answers

What is the purpose of isolating the feedwater connection to the boiler during the slow drain test?

To simulate a low water condition in the boiler. Signup and view all the answers

What is the maximum acceptable pressure during an accumulation test for a boiler with a MAWP of 1380 kPa and a safety valve set to 1310 kPa?

1389 kPa Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

The boiler should be shut down immediately and repaired. Signup and view all the answers

What is the purpose of the float chamber blowdown test?

To discharge sediment from the base of the float chamber. Signup and view all the answers

What should be checked closely during low water cut-off tests?

The boiler water level. Signup and view all the answers

What is the recommended frequency for performing the slow drain test on a heating boiler?

Semi-annually Signup and view all the answers

What is the primary purpose of the low water cut-off mechanism?

To shut off the boiler in the event of a low water condition. Signup and view all the answers

What is the advantage of the float chamber blowdown test?

It discharges sediment from the base of the float chamber. Signup and view all the answers

What is the purpose of closing the main burner test firing valve during a flame failure test?

To measure the time taken for the safety shut-off valve to close Signup and view all the answers

What is the recommended procedure for testing flame safeguard devices?

ASME BPVC VI Signup and view all the answers

What is the primary purpose of checking the feedwater pump or feedwater solenoid control during boiler operation?

To determine the level at which the feedwater system starts and stops Signup and view all the answers

What should be done annually to ensure the proper operation of low water cut-offs, pump controls, and water feeders?

Dismantle and inspect the devices for obstructions and proper operation Signup and view all the answers

Why is it necessary to follow manufacturer instructions when testing various devices?

To avoid damaging the equipment Signup and view all the answers

What is the purpose of the make-up valve in a combined feeder/cut-off control?

To feed make-up water in case of failure of the feedwater or condensate return pump Signup and view all the answers

What is the purpose of slowly opening the main burner test firing valve after simulating a flame failure?

To light the main burner Signup and view all the answers

What is the primary objective of performing regularly scheduled checks on safety devices in a boiler plant?

To ensure a safe and reliable boiler plant Signup and view all the answers

What should be observed during routine boiler monitoring to ensure the proper operation of the operating limit switch?

The cut-in and cut-off pressures of the operating limit switch Signup and view all the answers

What is the recommended frequency for checking the boiler flame failure detection systems according to ASME CSD-1?

Weekly Signup and view all the answers

What is the purpose of testing the high-pressure cut-off control in a steam boiler?

To ensure the boiler shuts down at a pressure higher than the set point of the operating limit control Signup and view all the answers

What should be done to the power to the boiler controls before testing the high-pressure cut-off control?

Disconnect the power to the boiler controls and verify power is off using a test meter Signup and view all the answers

What is the purpose of testing the flame failure device on a boiler?

To ensure the safety of the boiler plant Signup and view all the answers

Why is it necessary to perform tests on safety devices while the boiler is operating?

To test the safety devices under actual operating conditions Signup and view all the answers

What should be done after the high-pressure cut-off control has operated and shut down the firing equipment?

Manually reset the high-pressure cut-off control Signup and view all the answers

What should be checked for any deterioration during annual maintenance and inspection of low water cut-offs, pump controls, and water feeders?

All of the above Signup and view all the answers

Why is it important to mark the levels at which the feedwater system starts and stops on the gauge glass?

To record the levels for future reference and detect any changes Signup and view all the answers

What should be done if the low water cut-off proves defective during a test?

Repair or replace the device immediately Signup and view all the answers

Study Notes

Performing Scheduled Checks on Safety Devices

Performing regular checks on safety devices ensures a safe and reliable boiler plant.
ASME CSD-1 recommends a weekly check of the boiler flame failure detection systems.

Flame Safeguard Devices

To test the flame failure device on a boiler, simulate a flame failure condition.
Manufacturer testing instructions must be followed.
ASME BPVC VI describes the recommended procedure for testing flame safeguard devices.

Testing Flame Failure Devices

Gas Burner with a Thermocouple or Thermopile Flame Sensor:
- Close the main burner test firing valve and turn off the pilot burner test firing valve.
- Note the time required for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with an Electronic Flame Rod and Continuous Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with Electronic Flame Rod and Interrupted Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, reset the combustion controls and relight the pilot.
Gas Burner with Electronic Flame Scanner:
- Method 1: same as procedure 3
- Method 2:
  - Remove the scanner from its sighting tube and cover it.
  - Note the time it takes for the safety shut-off valve to close.
  - If the test is successful, reset the combustion controls and relight the pilot.
Oil Burner with Electronic Flame Scanner:
- Close the manual test firing valve in the oil supply line.
- Note the time it takes for the oil solenoid valve (safety shut-off valve) to close.

Checking Pilot Flame Failure Response

Close the main burner test firing valve and pilot burner test firing valve.
Start the boiler programmed combustion control.
The pilot safety shut-off valve should close at the end of the pilot trial-for-ignition period.

Checking Main Flame Failure Response

Close the main burner and pilot burner test firing valves.
Reset the programmed combustion control lockout switch.
Open the pilot burner test firing valve.
Turn the burner on and note the main fuel safety shut-off valve de-energizing.

Maintenance of Flame Safeguard Devices

The programmed combustion control requires no maintenance other than occasional blowing out of accumulated dust.
The scanner should never get so hot that it cannot be held comfortably in the hand.
Ensure the scanner tube has adequate air supply to keep it cool.
Clean the scanner lens regularly.
Ultraviolet flame scanners have a life of around 40,000 hours and may need to be replaced when they fail to discriminate between flame light and ambient light.

Low Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the low gas pressure cut-off switch.
The switch can be tested during boiler operation by slowly closing the main gas valve upstream of the low gas pressure switch.

High Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the high gas pressure cut-off switch.
The switch can be tested while the boiler is operating by quickly closing the main burner test firing valve.

Combustion Air Proving Switch

ASME CSD-1 recommends monthly testing of the combustion air proving switch.
Testing procedures vary by manufacturer and require approved, site-specific procedures.

Safety and Safety Relief Valves

ASME BPVC VI and VII outline the minimum frequency of safety valve checks.
The three tests commonly performed to test safety and safety relief valves are:
1. Try lever test (manual check)
2. Pop test (pressure test)
3. Accumulation test### Low Water Cut-Off Testing
Piping connections to the drum must be checked, and any obstructions removed.
The switch box cover should be removed to check the switch mechanisms for freedom of movement.
If the low water cut-off proves defective, the boiler should be removed from service until it is repaired or replaced.
ASME CSD-1 recommends daily testing for power boilers and weekly testing for heating boilers.

Testing Methods

Isolating the feedwater and blowing off the boiler (a slow drain test):
- Isolate the feedwater connection to the boiler.
- Perform a bottom blowoff.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.
Isolating the feedwater and allowing the boiler to steam off water:
- Isolate the feedwater connection to the boiler.
- Let the water level decrease as the boiler steams.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.

Feedwater Pump or Feedwater Solenoid Control

Steam boilers may use a combination boiler feedwater control and low water fuel cut-off.
The feedwater control may activate a feedwater solenoid valve or control a boiler feed pump.
These devices can be checked in the same manner as a dedicated low water cut-off control.
If the feedwater supply operates on two-position control, the operation of the pump or feedwater valve can be checked by observing the levels at which the feedwater system starts and stops.

Combined Feeder/Cut-Off Controls

Some steam heating boilers use combined feeder/cut-off controls.
These controls feed make-up water in case of failure of the feedwater or condensate return pump.
The operation of the make-up valve can be checked by shutting down the feed pump.
The make-up valve should open somewhat below the cut-in level of the pump and should be able to maintain proper level when the boiler is at full load.

Annual Maintenance and Inspection

Low water cut-offs, pump controls, and water feeders should be dismantled annually by qualified personnel.
These devices should be checked for obstructions, and proper operation of all parts must be verified.
Leaks in connecting lines to the boiler should be repaired, and connecting lines inspected for sediment and scale.

Operating Limit Switch

The operating limit switch does not require special testing as its operation can be observed during routine boiler monitoring.
Cut-in and cut-off pressures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need adjustment.

High-Pressure Cut-Off Control

The high-pressure cut-off control cannot be tested during normal boiler operation.
To test the high-pressure cut-off control:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating cut-off control.
- Record the setting of the high-pressure cut-off control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the steam pressure reaches the setting of the high-pressure cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Flow Switch

Copper tubular and copper fin-tube boilers require positive water circulation to protect the heat transfer surfaces from failure due to overheating.
To test the flow switch, slowly close the boiler outlet valve and observe the burner.
If the burner fails to shut down, or if hammering sounds occur, open the outlet valve fully.

Low Water Cut-Off (Hot Water Boilers)

Hot water boilers and their piping systems are completely filled with water.
The low water cut-off float chambers are directly connected to the boiler above the lowest permissible water level, with no intervening valves.
Therefore, opening the low water cut-off drain valve will not empty the float chamber and activate the cut-off.
ASME BPVC IV recommends testing the low water cut-off of hot water heating boilers monthly, as long as it can be done by draining only minimal amounts of water from the system.

Operating Limit Switch (Temperature Control)

The operating limit switch does not require special testing, because its operation can be observed during routine boiler monitoring.
Cut-in and cut-off temperatures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need to be adjusted.

High Temperature Cut-Off

The high temperature cut-off cannot be tested during normal boiler operation, since it operates above the cut-off point of the operating control.
To test the high temperature cut-off:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating temperature control.
- Record the setting of the high limit control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the water temperature reaches the setting of the high temperature cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Performing Scheduled Checks on Safety Devices

Performing regular checks on safety devices ensures a safe and reliable boiler plant.
ASME CSD-1 recommends a weekly check of the boiler flame failure detection systems.

Flame Safeguard Devices

To test the flame failure device on a boiler, simulate a flame failure condition.
Manufacturer testing instructions must be followed.
ASME BPVC VI describes the recommended procedure for testing flame safeguard devices.

Testing Flame Failure Devices

Gas Burner with a Thermocouple or Thermopile Flame Sensor:
- Close the main burner test firing valve and turn off the pilot burner test firing valve.
- Note the time required for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with an Electronic Flame Rod and Continuous Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with Electronic Flame Rod and Interrupted Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, reset the combustion controls and relight the pilot.
Gas Burner with Electronic Flame Scanner:
- Method 1: same as procedure 3
- Method 2:
  - Remove the scanner from its sighting tube and cover it.
  - Note the time it takes for the safety shut-off valve to close.
  - If the test is successful, reset the combustion controls and relight the pilot.
Oil Burner with Electronic Flame Scanner:
- Close the manual test firing valve in the oil supply line.
- Note the time it takes for the oil solenoid valve (safety shut-off valve) to close.

Checking Pilot Flame Failure Response

Close the main burner test firing valve and pilot burner test firing valve.
Start the boiler programmed combustion control.
The pilot safety shut-off valve should close at the end of the pilot trial-for-ignition period.

Checking Main Flame Failure Response

Close the main burner and pilot burner test firing valves.
Reset the programmed combustion control lockout switch.
Open the pilot burner test firing valve.
Turn the burner on and note the main fuel safety shut-off valve de-energizing.

Maintenance of Flame Safeguard Devices

The programmed combustion control requires no maintenance other than occasional blowing out of accumulated dust.
The scanner should never get so hot that it cannot be held comfortably in the hand.
Ensure the scanner tube has adequate air supply to keep it cool.
Clean the scanner lens regularly.
Ultraviolet flame scanners have a life of around 40,000 hours and may need to be replaced when they fail to discriminate between flame light and ambient light.

Low Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the low gas pressure cut-off switch.
The switch can be tested during boiler operation by slowly closing the main gas valve upstream of the low gas pressure switch.

High Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the high gas pressure cut-off switch.
The switch can be tested while the boiler is operating by quickly closing the main burner test firing valve.

Combustion Air Proving Switch

ASME CSD-1 recommends monthly testing of the combustion air proving switch.
Testing procedures vary by manufacturer and require approved, site-specific procedures.

Safety and Safety Relief Valves

ASME BPVC VI and VII outline the minimum frequency of safety valve checks.
The three tests commonly performed to test safety and safety relief valves are:
1. Try lever test (manual check)
2. Pop test (pressure test)
3. Accumulation test### Low Water Cut-Off Testing
Piping connections to the drum must be checked, and any obstructions removed.
The switch box cover should be removed to check the switch mechanisms for freedom of movement.
If the low water cut-off proves defective, the boiler should be removed from service until it is repaired or replaced.
ASME CSD-1 recommends daily testing for power boilers and weekly testing for heating boilers.

Testing Methods

Isolating the feedwater and blowing off the boiler (a slow drain test):
- Isolate the feedwater connection to the boiler.
- Perform a bottom blowoff.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.
Isolating the feedwater and allowing the boiler to steam off water:
- Isolate the feedwater connection to the boiler.
- Let the water level decrease as the boiler steams.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.

Feedwater Pump or Feedwater Solenoid Control

Steam boilers may use a combination boiler feedwater control and low water fuel cut-off.
The feedwater control may activate a feedwater solenoid valve or control a boiler feed pump.
These devices can be checked in the same manner as a dedicated low water cut-off control.
If the feedwater supply operates on two-position control, the operation of the pump or feedwater valve can be checked by observing the levels at which the feedwater system starts and stops.

Combined Feeder/Cut-Off Controls

Some steam heating boilers use combined feeder/cut-off controls.
These controls feed make-up water in case of failure of the feedwater or condensate return pump.
The operation of the make-up valve can be checked by shutting down the feed pump.
The make-up valve should open somewhat below the cut-in level of the pump and should be able to maintain proper level when the boiler is at full load.

Annual Maintenance and Inspection

Low water cut-offs, pump controls, and water feeders should be dismantled annually by qualified personnel.
These devices should be checked for obstructions, and proper operation of all parts must be verified.
Leaks in connecting lines to the boiler should be repaired, and connecting lines inspected for sediment and scale.

Operating Limit Switch

The operating limit switch does not require special testing as its operation can be observed during routine boiler monitoring.
Cut-in and cut-off pressures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need adjustment.

High-Pressure Cut-Off Control

The high-pressure cut-off control cannot be tested during normal boiler operation.
To test the high-pressure cut-off control:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating cut-off control.
- Record the setting of the high-pressure cut-off control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the steam pressure reaches the setting of the high-pressure cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Flow Switch

Copper tubular and copper fin-tube boilers require positive water circulation to protect the heat transfer surfaces from failure due to overheating.
To test the flow switch, slowly close the boiler outlet valve and observe the burner.
If the burner fails to shut down, or if hammering sounds occur, open the outlet valve fully.

Low Water Cut-Off (Hot Water Boilers)

Hot water boilers and their piping systems are completely filled with water.
The low water cut-off float chambers are directly connected to the boiler above the lowest permissible water level, with no intervening valves.
Therefore, opening the low water cut-off drain valve will not empty the float chamber and activate the cut-off.
ASME BPVC IV recommends testing the low water cut-off of hot water heating boilers monthly, as long as it can be done by draining only minimal amounts of water from the system.

Operating Limit Switch (Temperature Control)

The operating limit switch does not require special testing, because its operation can be observed during routine boiler monitoring.
Cut-in and cut-off temperatures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need to be adjusted.

High Temperature Cut-Off

The high temperature cut-off cannot be tested during normal boiler operation, since it operates above the cut-off point of the operating control.
To test the high temperature cut-off:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating temperature control.
- Record the setting of the high limit control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the water temperature reaches the setting of the high temperature cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Performing Scheduled Checks on Safety Devices

Performing regular checks on safety devices ensures a safe and reliable boiler plant.
ASME CSD-1 recommends a weekly check of the boiler flame failure detection systems.

Flame Safeguard Devices

To test the flame failure device on a boiler, simulate a flame failure condition.
Manufacturer testing instructions must be followed.
ASME BPVC VI describes the recommended procedure for testing flame safeguard devices.

Testing Flame Failure Devices

Gas Burner with a Thermocouple or Thermopile Flame Sensor:
- Close the main burner test firing valve and turn off the pilot burner test firing valve.
- Note the time required for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with an Electronic Flame Rod and Continuous Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, open the pilot burner test firing valve and relight the pilot.
Gas Burner with Electronic Flame Rod and Interrupted Pilot:
- Close the main burner test firing valve and note the time it takes for the safety shut-off valve to close.
- If the test is successful, reset the combustion controls and relight the pilot.
Gas Burner with Electronic Flame Scanner:
- Method 1: same as procedure 3
- Method 2:
  - Remove the scanner from its sighting tube and cover it.
  - Note the time it takes for the safety shut-off valve to close.
  - If the test is successful, reset the combustion controls and relight the pilot.
Oil Burner with Electronic Flame Scanner:
- Close the manual test firing valve in the oil supply line.
- Note the time it takes for the oil solenoid valve (safety shut-off valve) to close.

Checking Pilot Flame Failure Response

Close the main burner test firing valve and pilot burner test firing valve.
Start the boiler programmed combustion control.
The pilot safety shut-off valve should close at the end of the pilot trial-for-ignition period.

Checking Main Flame Failure Response

Close the main burner and pilot burner test firing valves.
Reset the programmed combustion control lockout switch.
Open the pilot burner test firing valve.
Turn the burner on and note the main fuel safety shut-off valve de-energizing.

Maintenance of Flame Safeguard Devices

The programmed combustion control requires no maintenance other than occasional blowing out of accumulated dust.
The scanner should never get so hot that it cannot be held comfortably in the hand.
Ensure the scanner tube has adequate air supply to keep it cool.
Clean the scanner lens regularly.
Ultraviolet flame scanners have a life of around 40,000 hours and may need to be replaced when they fail to discriminate between flame light and ambient light.

Low Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the low gas pressure cut-off switch.
The switch can be tested during boiler operation by slowly closing the main gas valve upstream of the low gas pressure switch.

High Gas Pressure Cut-Off Switch

ASME CSD-1 recommends monthly testing of the high gas pressure cut-off switch.
The switch can be tested while the boiler is operating by quickly closing the main burner test firing valve.

Combustion Air Proving Switch

ASME CSD-1 recommends monthly testing of the combustion air proving switch.
Testing procedures vary by manufacturer and require approved, site-specific procedures.

Safety and Safety Relief Valves

ASME BPVC VI and VII outline the minimum frequency of safety valve checks.
The three tests commonly performed to test safety and safety relief valves are:
1. Try lever test (manual check)
2. Pop test (pressure test)
3. Accumulation test### Low Water Cut-Off Testing
Piping connections to the drum must be checked, and any obstructions removed.
The switch box cover should be removed to check the switch mechanisms for freedom of movement.
If the low water cut-off proves defective, the boiler should be removed from service until it is repaired or replaced.
ASME CSD-1 recommends daily testing for power boilers and weekly testing for heating boilers.

Testing Methods

Isolating the feedwater and blowing off the boiler (a slow drain test):
- Isolate the feedwater connection to the boiler.
- Perform a bottom blowoff.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.
Isolating the feedwater and allowing the boiler to steam off water:
- Isolate the feedwater connection to the boiler.
- Let the water level decrease as the boiler steams.
- Confirm that the boiler trips at no lower than the lowest visible part of the gauge glass.

Feedwater Pump or Feedwater Solenoid Control

Steam boilers may use a combination boiler feedwater control and low water fuel cut-off.
The feedwater control may activate a feedwater solenoid valve or control a boiler feed pump.
These devices can be checked in the same manner as a dedicated low water cut-off control.
If the feedwater supply operates on two-position control, the operation of the pump or feedwater valve can be checked by observing the levels at which the feedwater system starts and stops.

Combined Feeder/Cut-Off Controls

Some steam heating boilers use combined feeder/cut-off controls.
These controls feed make-up water in case of failure of the feedwater or condensate return pump.
The operation of the make-up valve can be checked by shutting down the feed pump.
The make-up valve should open somewhat below the cut-in level of the pump and should be able to maintain proper level when the boiler is at full load.

Annual Maintenance and Inspection

Low water cut-offs, pump controls, and water feeders should be dismantled annually by qualified personnel.
These devices should be checked for obstructions, and proper operation of all parts must be verified.
Leaks in connecting lines to the boiler should be repaired, and connecting lines inspected for sediment and scale.

Operating Limit Switch

The operating limit switch does not require special testing as its operation can be observed during routine boiler monitoring.
Cut-in and cut-off pressures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need adjustment.

High-Pressure Cut-Off Control

The high-pressure cut-off control cannot be tested during normal boiler operation.
To test the high-pressure cut-off control:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating cut-off control.
- Record the setting of the high-pressure cut-off control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the steam pressure reaches the setting of the high-pressure cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Flow Switch

Copper tubular and copper fin-tube boilers require positive water circulation to protect the heat transfer surfaces from failure due to overheating.
To test the flow switch, slowly close the boiler outlet valve and observe the burner.
If the burner fails to shut down, or if hammering sounds occur, open the outlet valve fully.

Low Water Cut-Off (Hot Water Boilers)

Hot water boilers and their piping systems are completely filled with water.
The low water cut-off float chambers are directly connected to the boiler above the lowest permissible water level, with no intervening valves.
Therefore, opening the low water cut-off drain valve will not empty the float chamber and activate the cut-off.
ASME BPVC IV recommends testing the low water cut-off of hot water heating boilers monthly, as long as it can be done by draining only minimal amounts of water from the system.

Operating Limit Switch (Temperature Control)

The operating limit switch does not require special testing, because its operation can be observed during routine boiler monitoring.
Cut-in and cut-off temperatures should be observed and compared to the expected range.
If operating parameters differ from the expected range, the switch will need to be adjusted.

High Temperature Cut-Off

The high temperature cut-off cannot be tested during normal boiler operation, since it operates above the cut-off point of the operating control.
To test the high temperature cut-off:
- Disconnect power to the boiler controls.
- Place a test lead (jumper wire) across the terminals of the operating temperature control.
- Record the setting of the high limit control.
- Restore power to the controls and start the boiler.
- Allow the boiler to fire until the water temperature reaches the setting of the high temperature cut-off control.
- The control should operate at this point, and shut down the firing equipment.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the regular safety checks performed on boilers, including combustion controls, low water cut-offs, and high limit controls. It covers the recommended testing schedule and procedures.