4AE3 U12 C5 Review

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What is the source of impurities in boilers?

Water treatment chemicals
Both make-up water and condensate returning from steam-utilizing processes (correct)
Only make-up water
Condensate returning from steam-utilizing processes

What happens to the impurities when water treatment chemicals are added to the boiler water?

They are unaffected by the chemicals
They are completely removed from the boiler water
They react with the chemicals and form new compounds that remain dissolved
They react with the chemicals and form new compounds that precipitate from solution (correct)

What can happen if impurities are left unaddressed in boilers?

Impurities are completely removed from the boiler water
Boiler efficiency increases
Waterside scale and corrosion occur (correct)
Boiler metal becomes stronger

What can happen when precipitates settle out in boilers?

They can bake onto heat transfer surfaces or obstruct boiler water circulation (D) Signup and view all the answers

What can happen when impurities increase in concentration in the boiler water?

The tendency for boilers to carry-over impurities with the steam increases (A) Signup and view all the answers

What can happen when scale-forming compounds are deposited in the superheater tubing?

Superheater overheating and failure occur (D) Signup and view all the answers

What is the term used to describe the accumulated precipitated and suspended matter at the base of a boiler shell?

Mud (C) Signup and view all the answers

What is the primary factor that affects the rate of precipitate formation in a boiler system?

Make-up water quality (D) Signup and view all the answers

Why is it necessary to use high-quality make-up water in boilers with high make-up requirements?

To prevent mud and scale formation (D) Signup and view all the answers

What is the purpose of Bottom Blowoff in a boiler system?

To remove accumulated sediment at the base of the boiler (D) Signup and view all the answers

What is the recommended frequency of Bottom Blowoff according to ASME VII?

At least once every 24 hours (D) Signup and view all the answers

What is the effect of flashing water when blowoff valves are opened?

Vibration and shaking in the blowoff line (B) Signup and view all the answers

What is the purpose of designing blowoff piping for shock service?

To withstand the shock and thermal expansion of the blowoff piping (B) Signup and view all the answers

What are the components of a Bottom Blowoff system?

Blowoff valves, blowoff piping, and blowoff vessels (D) Signup and view all the answers

What is the primary consideration when designing blowoff valves?

Material strength and resistance to erosion (C) Signup and view all the answers

What is the exception to the requirement for blowoff piping in boilers?

Hot water heating boilers (A) Signup and view all the answers

What is a result of carryover in steam boilers?

Deposits of silica on turbine blading (A) Signup and view all the answers

What is the purpose of blowdown and blowoff in steam boilers?

To prevent the accumulation of sediment and dissolved solids (D) Signup and view all the answers

What is the main difference between blowoff and blowdown systems in heating boilers and power boilers?

Heating boilers have less robust blowoff and blowdown systems (C) Signup and view all the answers

What is the term 'bottom blowoff' referring to?

The intermittent removal of sediment accumulated in drums, shells, and headers (C) Signup and view all the answers

What is the ideal scenario for boiler feedwater sources?

Every kilogram of steam produced is returned to the boiler in a 100% pure state (D) Signup and view all the answers

What is the primary source of boiler water impurity?

Make-up water (D) Signup and view all the answers

What is the purpose of external water treatment equipment?

To convert dissolved calcium and magnesium compounds to sodium compounds (B) Signup and view all the answers

What is the purpose of internal chemical treatment in steam boilers?

To precipitate scale-forming calcium and magnesium (D) Signup and view all the answers

What is the result of carryover in terms of turbine efficiency?

Reduced turbine efficiency (C) Signup and view all the answers

What is the purpose of the blowoff line in steam boilers?

To blow out sediment and impurities from the boiler under pressure (D) Signup and view all the answers

What is the minimum number of boiler blowoff valves required by ASME B31.1?

One (C) Signup and view all the answers

What type of valve is shown in Figure 2?

Y-Type Globe Valve (A) Signup and view all the answers

What is the purpose of the port in the lower part of the plunger in a seatless slow-opening valve?

To allow boiler water to flow through the valve (A) Signup and view all the answers

What is the advantage of a Y-type valve over a regular globe valve?

It has a lower pressure drop (D) Signup and view all the answers

What is the function of the spring in a quick-opening valve?

To force the disc against the seat (D) Signup and view all the answers

What can happen if a quick-opening valve is left leaking for a long time?

The valve seat and disc will wire draw (D) Signup and view all the answers

What type of valve is required by ASME B31.1 to be at least one in a power boiler?

Slow-Opening Valve (C) Signup and view all the answers

What is the characteristic of a slow-opening valve?

It requires at least five 360° turns of the operating mechanism to open or shut (A) Signup and view all the answers

What is the purpose of the markings on a quick-opening valve?

To indicate the valve is open or shut (D) Signup and view all the answers

What happens when the plunger hole in a seatless slow-opening valve aligns with the valve inlet?

The valve is open (C) Signup and view all the answers

What is the primary purpose of blowoff piping?

To allow for thermal expansion and contraction (C) Signup and view all the answers

What is the function of a blowoff vessel?

To depressurize and cool the blowoff water (B) Signup and view all the answers

What is the minimum pressure requirement for the installation of a blowoff vessel?

103 kPa (C) Signup and view all the answers

What is the purpose of the inlet line in a blowoff vessel?

To mix the incoming hot water with the cooler water in the tank (A) Signup and view all the answers

What is the maximum temperature allowed for the blowoff water at the outlet of the blowoff vessel?

65°C (C) Signup and view all the answers

What is the purpose of the anti-siphon hole in a blowoff vessel?

To prevent the vessel from draining completely (B) Signup and view all the answers

What is the result of inadequate blowoff?

Increased sediment accumulation and adhesion to heat transfer surfaces (D) Signup and view all the answers

What is the purpose of quenching water in some blowoff vessels?

To cool the blowoff water to a safe temperature (A) Signup and view all the answers

What is the ASME code that specifies the materials and design of power boiler blowdown piping?

ASME B31.1 (D) Signup and view all the answers

Why is it important to anchor blowoff piping to prevent transmission of motion back to the boiler?

To prevent damage to the boiler and its components (C) Signup and view all the answers

What is the primary reason for positioning bottom blowoff valves at the lowest parts of the boiler?

To prevent the accumulation of suspended matter at the bottom of the water space (A) Signup and view all the answers

Why is it essential to lock out and tag boilers open for maintenance or inspection during bottom blowoff?

To prevent blowoff water from entering the open drum of another boiler (D) Signup and view all the answers

What is the primary purpose of having an assistant watch the gauge glass during bottom blowoff?

To warn the operator if the boiler water level gets too low (C) Signup and view all the answers

What should be done with blowoff valves after a blowoff operation is complete?

Confirm they are shut and verify the sequence (C) Signup and view all the answers

What is the recommended practice for operating blowoff valves during bottom blowoff?

Open and close them slowly to prevent water hammer (C) Signup and view all the answers

Why is it important to visibly number or identify boilers in a multiple boiler plant?

To prevent blowing off the wrong boiler (D) Signup and view all the answers

What is the purpose of quenching water during bottom blowoff?

To prevent thermal shock (D) Signup and view all the answers

Why is it recommended to perform bottom blowoff when the boiler load is low or moderate?

To minimize disruption to boiler water circulation (D) Signup and view all the answers

What is the purpose of the valve closest to the boiler in a blowoff valve combination?

To protect the valve from erosive action (D) Signup and view all the answers

What should be done during a bottom blowoff operation to prevent water hammer?

Open the blowoff valves slowly and in the proper sequence (A) Signup and view all the answers

What is the purpose of a guard valve in a combination quick-opening and slow-opening valve arrangement?

To act as a shut-off valve adjacent to the boiler (D) Signup and view all the answers

What is the recommended sequence for opening and closing valves in a combination quick-opening and slow-opening valve arrangement?

Open the guard valve first and close it last, and open the blowoff valve last and close it first (D) Signup and view all the answers

What can happen if the correct operating sequence is not followed when using two seatless slow-opening valves?

The valve body may crack due to water compression (C) Signup and view all the answers

What is the purpose of a surface blowoff system in a boiler?

To remove impurities from the boiler water surface (D) Signup and view all the answers

What is the importance of using a graduated metering valve in a continuous surface blowoff system?

It allows for more precise control of the blowoff flow rate (A) Signup and view all the answers

Why is it important to follow the correct operating sequence when using two hard-seated slow-opening valves?

To ensure one valve is the guard valve and the other is the blowing valve (A) Signup and view all the answers

What is the purpose of the perforated pipe in a surface blowoff system?

To remove impurities from the boiler water surface (A) Signup and view all the answers

What can happen if the blowoff valve is pumped to blow off the boiler?

Water hammer will occur (D) Signup and view all the answers

Why is it important to ensure that the valve furthest from the boiler is opened first and closed last when using two seatless slow-opening valves?

To prevent water from becoming trapped between the valves (C) Signup and view all the answers

What is the purpose of the isolation valve in a surface blowoff system?

To isolate the boiler from the blowoff system (A) Signup and view all the answers

What is the primary consequence of impurities being left unaddressed in boilers?

Creation of waterside scale and corrosion (C) Signup and view all the answers

What is the purpose of adding water treatment chemicals to the boiler water?

To react with impurities and form precipitates that can settle out (A) Signup and view all the answers

What is the result of precipitates settling out in low water cutoff float cages and water columns?

Interference with cutoff and gauge glass operation (C) Signup and view all the answers

Why do impurities increase in concentration in the boiler water as the boiler operates?

Because of the concentration of impurities in the feedwater (B) Signup and view all the answers

What is the consequence of carryover in steam boilers?

Deposits of scale-forming compounds in the superheater tubing (A) Signup and view all the answers

What is the source of impurities in boilers?

Make-up water and condensate returning from steam-utilizing processes (D) Signup and view all the answers

What is the primary consequence of not performing blowdown and blowoff in steam boilers?

Scale formation and sediment accumulation (C) Signup and view all the answers

Why is make-up water a primary source of boiler water impurity?

It contains varying amounts of suspended matter, dissolved solids, and dissolved gases (D) Signup and view all the answers

What is the purpose of adding chemicals to boiler water?

To precipitate scale-forming calcium and magnesium (A) Signup and view all the answers

What can happen if impurities are not removed from the boiler water?

Scale formation and sediment accumulation will occur (A) Signup and view all the answers

What is the difference between surface blowoff and bottom blowoff?

Surface blowoff removes sediment, while bottom blowoff removes dissolved solids (A) Signup and view all the answers

Why is it important to ensure that the blowdown system is operated correctly?

To prevent the accumulation of sediment and dissolved solids (B) Signup and view all the answers

What is the result of not treating make-up water before adding it to the boiler?

Impurities will enter the boiler and cause problems (C) Signup and view all the answers

What is the purpose of external water treatment equipment?

To convert calcium and magnesium compounds to sodium compounds (A) Signup and view all the answers

What is the cause of carryover in steam boilers?

All of the above (D) Signup and view all the answers

What is the result of carryover in terms of turbine efficiency?

Decreased efficiency (B) Signup and view all the answers

What is the primary factor that affects the rate of precipitate formation in a boiler system with high steam production?

Quality of make-up water (D) Signup and view all the answers

Why is it necessary to design blowoff piping for shock service?

To prevent all of the above (D) Signup and view all the answers

What is the characteristic of a blowoff valve that is specially designed for severe service?

It is made of materials that are strong at high pressures and temperatures (B) Signup and view all the answers

What is the minimum design pressure of the blowoff piping system components that exceeds the MAWP of the boiler?

It is specified in ASME B31.1 (C) Signup and view all the answers

What is the purpose of the anti-siphon hole in a blowoff vessel?

To prevent the formation of a vacuum in the vessel (A) Signup and view all the answers

What is the result of inadequate blowoff in a boiler system?

The formation of mud and scale in the boiler (B) Signup and view all the answers

What is the primary purpose of the frequency and duration of blowoff in a boiler system?

To remove accumulated sediment at the base of the boiler (D) Signup and view all the answers

What is the effect of flashing water when blowoff valves are opened?

A sudden temperature rise and the formation of steam (D) Signup and view all the answers

What is the purpose of the rules for blowoff valves and blowoff piping in ASME B31.1 and ASME IV?

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

What is the characteristic of a boiler system that requires high-quality make-up water?

It has a high make-up water requirement (B) Signup and view all the answers

What is the primary consideration for selecting the construction material of blowoff valves in power boilers?

Boiler pressure and temperature (B) Signup and view all the answers

What is the purpose of the stem angle in a Y-type globe valve?

To reduce the pressure drop across the valve (A) Signup and view all the answers

What is the primary characteristic of a slow-opening valve?

It requires multiple 360° turns of the operating mechanism to change from fully closed to fully open (D) Signup and view all the answers

What is the function of the port in the lower part of the plunger in a seatless slow-opening valve?

To facilitate the flow of boiler water through the valve (D) Signup and view all the answers

Why is it important to ensure that the valve does not leak for a long time in a quick-opening valve?

To prevent the valve seat and disc from wire drawing (D) Signup and view all the answers

What is the purpose of the markings on the body of a quick-opening valve?

To enable the operator to determine the valve's position (C) Signup and view all the answers

What is the advantage of using a Y-type valve over a regular globe valve?

It reduces the pressure drop across the valve and enables sediment and water to freely discharge (C) Signup and view all the answers

What is the purpose of the spring in a quick-opening valve?

To provide a tight seal between the valve disc and seat (C) Signup and view all the answers

What is the primary advantage of using a hard-seated valve over a seatless valve?

It is more durable and resistant to wear and tear (D) Signup and view all the answers

What is the purpose of the welded bonnet in a Y-type valve?

To enhance the valve's structural integrity and prevent leakage (B) Signup and view all the answers

What is the primary reason why waterwall header blowoff is never performed when large steam generating units are in operation?

To prevent loss of water circulation and exposure to overheating (B) Signup and view all the answers

What is the purpose of quenching water in some blowoff vessels?

To prevent thermal shock (C) Signup and view all the answers

Why is it important to ensure that any boilers open for maintenance or inspection are properly locked out and tagged during bottom blowoff?

To prevent blowoff water from entering the open drum of another boiler (D) Signup and view all the answers

What is the recommended practice when operating blowoff valves during bottom blowoff?

Open the valves slowly and in the proper sequence (A) Signup and view all the answers

What is the purpose of the valve closest to the boiler in a blowoff valve combination?

To protect the valve from the erosive action of the boiler water (C) Signup and view all the answers

What is the primary consideration when designing blowoff valves?

Preventing erosion of the valve (B) Signup and view all the answers

What can happen if the blowoff valves are not operated slowly and in the proper sequence during bottom blowoff?

Water hammer may occur (B) Signup and view all the answers

Why is it important to verify that quenching water is on before beginning the blowoff procedure?

To prevent thermal shock (C) Signup and view all the answers

What is the purpose of having an assistant watch the gauge glass during bottom blowoff?

To warn the operator if the boiler water level gets too low (A) Signup and view all the answers

What is the primary purpose of performing bottom blowoff?

To remove suspended matter and sediment from the boiler (D) Signup and view all the answers

What is the main purpose of the blowoff vessel in a boiler system?

To depressurize the blowoff water and cool it to a suitable temperature for the sewer system (C) Signup and view all the answers

According to the CSA B51 Code, what is the maximum temperature allowed for the blowoff water at the outlet of the blowoff vessel?

65°C (B) Signup and view all the answers

What is the primary purpose of the anchor in the blowoff piping system?

To prevent the transmission of motion from the piping to the boiler (A) Signup and view all the answers

What is the result of inadequate blowoff in a boiler system?

Sediment accumulation and adherence to heat transfer surfaces and other boiler parts (A) Signup and view all the answers

What is the primary function of the anti-siphon hole in a blowoff vessel?

To prevent the vessel from draining completely (D) Signup and view all the answers

What is the primary reason for using a slow-opening valve in a blowoff system?

To prevent water hammer (D) Signup and view all the answers

What is the purpose of the inlet line in a blowoff vessel?

To mix the incoming hot water with the cooler water in the vessel (C) Signup and view all the answers

What is the requirement for the installation of a blowoff vessel according to the CSA B51 Code?

For all boilers operating above 103 kPa gauge (A) Signup and view all the answers

What is the purpose of the valve closest to the boiler in a combination quick-opening and slow-opening valve arrangement?

To act as a guard valve (A) Signup and view all the answers

Why is it important to follow the correct operating sequence when using two seatless slow-opening valves?

To prevent valve damage (B) Signup and view all the answers

What is the purpose of the inspection and cleaning access in a blowoff vessel?

To facilitate the inspection and cleaning of the vessel (C) Signup and view all the answers

What is the purpose of a surface blowoff system in a boiler?

To remove impurities from the boiler water surface (D) Signup and view all the answers

What is the effect of excessive blowoff in a boiler system?

Discharge of treated water, internal treatment chemicals, and heat from the boiler (B) Signup and view all the answers

What is the purpose of the ASME B31.1 Power Piping Code in relation to blowoff piping?

To specify the materials and design of power boiler blowdown piping (A) Signup and view all the answers

What can happen if the correct operating sequence is not followed when using two hard-seated slow-opening valves?

The valve may be damaged (D) Signup and view all the answers

Why is it important to ensure that the valve furthest from the boiler is opened first and closed last when using two seatless slow-opening valves?

To prevent valve damage (C) Signup and view all the answers

What is the characteristic of a slow-opening valve in a blowoff system?

It opens slowly to reduce the possibility of water hammer (B) Signup and view all the answers

What is the purpose of an isolation valve in a surface blowoff system?

To isolate the surface blowoff system from the boiler (D) Signup and view all the answers

What can happen if the blowoff valve is pumped to blow off the boiler?

Water hammer may occur (B) Signup and view all the answers

What is the purpose of a guard valve in a combination quick-opening and slow-opening valve arrangement?

To ensure a leak-tight shut-off adjacent to the boiler (D) Signup and view all the answers

What is the primary reason for controlling the concentration of dissolved solids in boiler water?

To prevent carryover and impede heat transfer (A) Signup and view all the answers

What are the examples of dissolved solids in boiler water?

Various sodium compounds, such as carbonates, bicarbonates, chlorides, and phosphates (A) Signup and view all the answers

What is the effect of high concentrations of dissolved solids in boiler water?

It can lead to carryover and impede heat transfer (A) Signup and view all the answers

How do dissolved solids enter the boiler water?

They enter the boiler with the make-up water, or return with the condensate (A) Signup and view all the answers

What is the purpose of continuous blowdown in boiler operation?

To control the concentration of dissolved solids in boiler water (A) Signup and view all the answers

What can happen if the concentration of dissolved solids is not controlled in boiler water?

It can lead to foaming and priming (D) Signup and view all the answers

What is the primary purpose of continuous blowdown in a boiler?

To control the concentration of dissolved solids in the boiler water (B) Signup and view all the answers

What is the main factor that determines the quality of feedwater required for a boiler?

Boiler operating pressure (A) Signup and view all the answers

What is the purpose of filtering and softening returns with condensate polishing equipment?

To remove suspended matter from the returns (B) Signup and view all the answers

What is the term used to describe the measurement of dissolved solids concentration in boiler water?

Specific conductance (D) Signup and view all the answers

What is the primary function of the internal continuous blowdown collection pipe in the steam drum?

To collect boiler water with the highest dissolved solids concentration (B) Signup and view all the answers

What is the purpose of measuring the solids concentration of the boiler water during continuous blowdown?

To adjust the metering valve to maintain the prescribed solids concentration (D) Signup and view all the answers

What is the purpose of the CBD valve in a blowdown system?

To control the flow of blowdown water to the blowoff vessel (B) Signup and view all the answers

What is the result of not controlling the concentration of dissolved solids in the boiler water?

Scale formation and potential boiler damage (A) Signup and view all the answers

What is the recommended practice for determining the blowdown rate?

Conducting regular water tests at the beginning of every shift (D) Signup and view all the answers

Why is it important to adjust the CBD valve carefully?

To prevent excessive blowdown and waste of treated water (C) Signup and view all the answers

What is the purpose of ASME B31.1 code in relation to blowdown systems?

To specify the materials and design of power boiler blowdown piping (C) Signup and view all the answers

What is the recommended material for blowdown piping in boilers operating at pressures higher than 690 kPa?

Steel, at least Schedule 80 (A) Signup and view all the answers

What is the primary purpose of installing a heat recovery system in a blowdown system?

To conserve heat energy and reduce energy losses (A) Signup and view all the answers

What is the effect of high-pressure boilers on the need for feedwater quality?

Increased need for high-quality feedwater (A) Signup and view all the answers

What is the purpose of ultra-pure make-up water in high-pressure boilers?

To reduce the need for internal boiler water treatment chemicals (C) Signup and view all the answers

What is the effect of excessive continuous blowdown on a boiler system?

It wastes treated water, chemicals, and heat (B) Signup and view all the answers

What is the purpose of the vernier scale on a CBD valve?

To indicate the valve position and facilitate fine flow control (C) Signup and view all the answers

What factor determines the design pressure of the blowdown piping system?

The boiler's MAWP (C) Signup and view all the answers

What is the primary reason for installing a single shut-off valve in the CBD line?

To isolate the boiler from the blowdown system (C) Signup and view all the answers

What is the purpose of adjusting the flow of blowdown water in a boiler system?

To regulate the TDS concentration in the boiler water (B) Signup and view all the answers

What is the primary benefit of using an automated continuous blowdown system?

Reducing the total amount of blowdown and fuel costs (B) Signup and view all the answers

What is the purpose of the heat exchanger in a blowdown heat recovery system?

To recover heat from the blowdown water and preheat the make-up water (C) Signup and view all the answers

Why is it important to regularly inspect the blowoff system?

To prevent thermal shock and wear and tear on components (D) Signup and view all the answers

What is the recommended material for blowoff piping operating above 690 kPa?

Schedule 80 steel (D) Signup and view all the answers

What is the purpose of the 45° elbow in blowoff piping?

To reduce the risk of erosion and corrosion (A) Signup and view all the answers

What should be done if a valve is found damaged during inspection?

Replace it with the exact same valve (D) Signup and view all the answers

What is the benefit of increasing the temperature of the feedwater by 5°C?

A 1% increase in efficiency (C) Signup and view all the answers

What is the purpose of the solenoid valve in an automated continuous blowdown system?

To shut off the blowdown flow when the boiler is off (B) Signup and view all the answers

What is the consequence of not repairing or replacing damaged blowoff system components?

Increased risk of explosion and damage to the system (B) Signup and view all the answers

What should be inspected during regular blowoff system inspection?

The boiler blowoff vessel, blowoff valves, and blowoff piping (C) Signup and view all the answers

What is the primary reason why dissolved solids in boiler water can lead to superheater failure?

The dissolved solids concentrate in the boiler water, carrying over with the wet steam and potentially depositing in the superheater banks, impeding heat transfer. (B) Signup and view all the answers

What is the primary source of impurities in boiler water?

All of the above are potential sources of impurities in boiler water. (D) Signup and view all the answers

What is the effect of high concentrations of dissolved solids in boiler water?

They can lead to carryover, foaming, and priming, reducing the overall efficiency of the boiler. (A) Signup and view all the answers

What is the purpose of controlling the concentration of dissolved solids in boiler water?

To prevent carryover, foaming, and priming, and to reduce the risk of superheater failure. (A) Signup and view all the answers

What is the primary function of chelants in boiler water treatment?

To react with impurities and form precipitates that can be removed from the boiler. (B) Signup and view all the answers

What is the result of inadequate control of dissolved solids in boiler water?

Increased risk of superheater failure, carryover, foaming, and priming, and reduced overall efficiency of the boiler. (B) Signup and view all the answers

What is the primary purpose of ultra-pure make-up water in high-pressure boilers?

To reduce the need for internal boiler water treatment chemicals (C) Signup and view all the answers

What is the primary characteristic of a boiler system that requires high-quality make-up water?

High-pressure boilers (D) Signup and view all the answers

What is the consequence of not performing continuous blowdown in steam boilers?

Scale formation (B) Signup and view all the answers

What is the primary factor that determines the blowdown rate in a boiler system?

Rate of steam production (B) Signup and view all the answers

What is the purpose of continuous blowdown in boiler operation?

To reduce the concentration of dissolved solids in the boiler water (A) Signup and view all the answers

What is the primary source of impurities in boilers?

Make-up water (B) Signup and view all the answers

What is the relationship between the electrical conductivity of water and its dissolved impurities?

The conductivity of water increases with increasing impurities (D) Signup and view all the answers

What is the primary purpose of measuring the solids concentration of the boiler water?

To determine the blowdown rate (A) Signup and view all the answers

What is the term used to describe the total dissolved solids (TDS) concentration in boiler water?

Specific conductance (A) Signup and view all the answers

What is the primary reason for using continuous blowdown in high-pressure boilers?

To reduce the need for internal boiler water treatment chemicals (C) Signup and view all the answers

What is the primary benefit of implementing an automated continuous blowdown system?

Reducing total blowdown and eliminating TDS swings (C) Signup and view all the answers

What is the primary purpose of inspecting blowoff system components?

To identify potential safety hazards and preventive maintenance (A) Signup and view all the answers

What is the recommended material for blowoff piping in boilers operating above 690 kPa?

Schedule 80 steel (B) Signup and view all the answers

What is the consequence of not performing regular blowoff system inspections and maintenance?

Thermal shock and component failure (B) Signup and view all the answers

What is the benefit of using a heat recovery system in a blowdown system?

Improving boiler efficiency by preheating feedwater (B) Signup and view all the answers

What is the purpose of the solenoid valve in an automated continuous blowdown system?

To shut off the blowdown flow when the boiler is off (C) Signup and view all the answers

What is the recommended procedure for repairing or replacing blowoff system components?

Following guidelines and using certified materials and welders (D) Signup and view all the answers

What is the primary consideration when selecting blowoff valve materials?

Material strength and corrosion resistance (B) Signup and view all the answers

What is the consequence of using inadequate or corroded blowoff piping components?

Component failure and explosion risk (A) Signup and view all the answers

What is the purpose of the heat exchanger in a blowdown heat recovery system?

To heat the make-up water (D) Signup and view all the answers

At what location is the internal continuous blowdown collection pipe installed in the steam drum or boiler shell?

About 15 cm below the normal operating water level (A) Signup and view all the answers

What is the primary purpose of controlling the TDS concentration in boiler water through continuous blowdown?

To prevent excessive carryover (D) Signup and view all the answers

What is the requirement for blowdown piping material in boilers operating at pressures higher than 690 kPa?

It must be steel, and at least Schedule 80 (A) Signup and view all the answers

What is the purpose of the vernier scale on a CBD valve?

To indicate the valve's opening position (B) Signup and view all the answers

Why is it necessary to carefully monitor and control manual continuous blowdown?

To prevent excessive blowdown waste (B) Signup and view all the answers

What is the typical percentage of the overall boiler steam flow rate for the CBD flow?

1% or more (D) Signup and view all the answers

What is the purpose of the CBD valve in a blowdown system?

To control the flow of blowdown water (A) Signup and view all the answers

What is the consequence of not opening the CBD valve sufficiently?

The TDS concentration will be too high (A) Signup and view all the answers

Why is it important to consider the rate of steam production and type of impurities in the make-up water when designing a blowdown system?

To determine the required blowdown rate (D) Signup and view all the answers

What is the advantage of using a V-notch plug valve in a blowdown system?

It provides more desirable flow characteristics (D) Signup and view all the answers

4AE3 U12 C5 Review

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What is the source of impurities in boilers?

What happens to the impurities when water treatment chemicals are added to the boiler water?

What can happen if impurities are left unaddressed in boilers?

What can happen when precipitates settle out in boilers?

What can happen when impurities increase in concentration in the boiler water?

What can happen when scale-forming compounds are deposited in the superheater tubing?

What is the term used to describe the accumulated precipitated and suspended matter at the base of a boiler shell?

What is the primary factor that affects the rate of precipitate formation in a boiler system?

Why is it necessary to use high-quality make-up water in boilers with high make-up requirements?

What is the purpose of Bottom Blowoff in a boiler system?

What is the recommended frequency of Bottom Blowoff according to ASME VII?

What is the effect of flashing water when blowoff valves are opened?

What is the purpose of designing blowoff piping for shock service?

What are the components of a Bottom Blowoff system?

What is the primary consideration when designing blowoff valves?

What is the exception to the requirement for blowoff piping in boilers?

What is a result of carryover in steam boilers?

What is the purpose of blowdown and blowoff in steam boilers?

What is the main difference between blowoff and blowdown systems in heating boilers and power boilers?

What is the term 'bottom blowoff' referring to?

What is the ideal scenario for boiler feedwater sources?

What is the primary source of boiler water impurity?

What is the purpose of external water treatment equipment?

What is the purpose of internal chemical treatment in steam boilers?

What is the result of carryover in terms of turbine efficiency?

What is the purpose of the blowoff line in steam boilers?

What is the minimum number of boiler blowoff valves required by ASME B31.1?

What type of valve is shown in Figure 2?

What is the purpose of the port in the lower part of the plunger in a seatless slow-opening valve?

What is the advantage of a Y-type valve over a regular globe valve?

What is the function of the spring in a quick-opening valve?

What can happen if a quick-opening valve is left leaking for a long time?

What type of valve is required by ASME B31.1 to be at least one in a power boiler?

What is the characteristic of a slow-opening valve?

What is the purpose of the markings on a quick-opening valve?

What happens when the plunger hole in a seatless slow-opening valve aligns with the valve inlet?

What is the primary purpose of blowoff piping?

What is the function of a blowoff vessel?

What is the minimum pressure requirement for the installation of a blowoff vessel?

What is the purpose of the inlet line in a blowoff vessel?

What is the maximum temperature allowed for the blowoff water at the outlet of the blowoff vessel?

What is the purpose of the anti-siphon hole in a blowoff vessel?

What is the result of inadequate blowoff?

What is the purpose of quenching water in some blowoff vessels?

What is the ASME code that specifies the materials and design of power boiler blowdown piping?

Why is it important to anchor blowoff piping to prevent transmission of motion back to the boiler?

What is the primary reason for positioning bottom blowoff valves at the lowest parts of the boiler?

Why is it essential to lock out and tag boilers open for maintenance or inspection during bottom blowoff?

What is the primary purpose of having an assistant watch the gauge glass during bottom blowoff?

What should be done with blowoff valves after a blowoff operation is complete?

What is the recommended practice for operating blowoff valves during bottom blowoff?

Why is it important to visibly number or identify boilers in a multiple boiler plant?

What is the purpose of quenching water during bottom blowoff?

Why is it recommended to perform bottom blowoff when the boiler load is low or moderate?

What is the purpose of the valve closest to the boiler in a blowoff valve combination?

What should be done during a bottom blowoff operation to prevent water hammer?

What is the purpose of a guard valve in a combination quick-opening and slow-opening valve arrangement?

What is the recommended sequence for opening and closing valves in a combination quick-opening and slow-opening valve arrangement?

What can happen if the correct operating sequence is not followed when using two seatless slow-opening valves?

What is the purpose of a surface blowoff system in a boiler?

What is the importance of using a graduated metering valve in a continuous surface blowoff system?

Why is it important to follow the correct operating sequence when using two hard-seated slow-opening valves?

What is the purpose of the perforated pipe in a surface blowoff system?

What can happen if the blowoff valve is pumped to blow off the boiler?

Why is it important to ensure that the valve furthest from the boiler is opened first and closed last when using two seatless slow-opening valves?

What is the purpose of the isolation valve in a surface blowoff system?

What is the primary consequence of impurities being left unaddressed in boilers?

What is the purpose of adding water treatment chemicals to the boiler water?

What is the result of precipitates settling out in low water cutoff float cages and water columns?

Why do impurities increase in concentration in the boiler water as the boiler operates?

What is the consequence of carryover in steam boilers?

What is the source of impurities in boilers?

What is the primary consequence of not performing blowdown and blowoff in steam boilers?

Why is make-up water a primary source of boiler water impurity?

What is the purpose of adding chemicals to boiler water?

What can happen if impurities are not removed from the boiler water?