4BE3.5 U3 C3 Obj 3 EMH
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Questions and Answers

EASY What is the purpose of a gauge glass in a boiler?

  • To control the boiler's heating system
  • To continuously determine the boiler water level (correct)
  • To monitor the boiler's fuel consumption
  • To measure steam pressure
  • According to ASME BPVC I Part PG-60.1, how many gauge glasses are required for boilers with a maximum allowable working pressure exceeding 400 psi?

  • Three
  • Four
  • One
  • Two (correct)
  • What is the minimum diameter of the unrestricted drain opening required for steam heating boilers?

  • 1/4 in. (correct)
  • 1/2 in.
  • 3/4 in.
  • 1/8 in.
  • Why is it critical to know the boiler water level at all times?

    <p>To prevent accidents and ensure safe operation</p> Signup and view all the answers

    What is the minimum distance required between the lowest visible water level in a gauge glass and the lowest permissible water level?

    <p>2 in.</p> Signup and view all the answers

    What is an alternative to one of the required gauge glasses for boilers?

    <p>Two remote water level indicators</p> Signup and view all the answers

    Which type of boiler requires a permanent indicator of the lowest permissible water level?

    <p>Heating boiler</p> Signup and view all the answers

    What is the purpose of the valved fittings attached to the water column or boiler?

    <p>To facilitate cleaning</p> Signup and view all the answers

    What is the simplest and least costly gauge glass design?

    <p>Tubular</p> Signup and view all the answers

    What is the purpose of the stainless steel check ball in the lower valve on the gauge glass?

    <p>To stop the flow of fluid when the glass breaks</p> Signup and view all the answers

    What determines the pressure ratings of gauge glass tubing?

    <p>All of the above</p> Signup and view all the answers

    What is the minimum overlap required for adjoining sections of gauge glass assemblies?

    <p>1 in.</p> Signup and view all the answers

    What is the purpose of the washer or packing ring and a nut at each end of the gauge glass tube?

    <p>To hold the gauge glass tube tightly in place</p> Signup and view all the answers

    What is the minimum size of piping required for connecting a water column to a steam boiler?

    <p>NPS 1 (DN 25)</p> Signup and view all the answers

    What is the purpose of the drain valve or cock on the lower gauge glass fitting?

    <p>To remove any solid material that may collect</p> Signup and view all the answers

    What is the purpose of the metal rods or transparent shield surrounding the gauge glass?

    <p>To protect the gauge glass from breakage</p> Signup and view all the answers

    What is the limitation of using tubular gauge glasses?

    <p>Low pressure and temperature</p> Signup and view all the answers

    What is the requirement for installing multiple gauge glasses?

    <p>The visible portions of the gauge glasses must overlap</p> Signup and view all the answers

    When inserting the gauge glass into the steam fitting, what should be done first?

    <p>Insert the gauge glass into the steam fitting first</p> Signup and view all the answers

    Why should the operator wear a face shield when opening the valves?

    <p>To prevent injury from steam or water</p> Signup and view all the answers

    What is the maximum pressure for which tubular gauge glasses are available?

    <p>3000 kPa</p> Signup and view all the answers

    What type of gauge glass is used for pressures up to 70 000 kPa?

    <p>Armored-Type (Flat)</p> Signup and view all the answers

    What is the purpose of the transparent mica coating on the inside surfaces of the glasses?

    <p>To prevent water from directly contacting the glass</p> Signup and view all the answers

    What is the recommended method for tightening the bolts on the transparent gauge glass?

    <p>Starting at the centre and working outwards</p> Signup and view all the answers

    What is the purpose of the reflex gauge?

    <p>To create a sharp line of demarcation at the liquid level</p> Signup and view all the answers

    What is the first step in replacing the armored-type (flat) gauge glass?

    <p>Close the steam and water valves on the gauge glass and open the drain valve</p> Signup and view all the answers

    Why should the surfaces of the gauge body and the bolted covers be polished perfectly smooth?

    <p>To prevent the gasket material from plugging the valves on the gauge</p> Signup and view all the answers

    Why should the old gauge glasses not be reused?

    <p>Because they are no longer suitable for high temperature high-pressure service</p> Signup and view all the answers

    What is the purpose of the drain valve in the installation shown in Figure 15?

    <p>To permit all the connections to be blown through</p> Signup and view all the answers

    What is the purpose of the water column in the installation shown in Figure 16?

    <p>To dampen agitation in the water and trap sludge or sediment</p> Signup and view all the answers

    What was the purpose of try cocks in the past?

    <p>To provide a means of point level detection when the gauge glass is being replaced</p> Signup and view all the answers

    What is the minimum distance between the lowest visible water level in the gauge glass and the lowest permissible water level in a boiler, according to ASME BPVC I Part PG-60.1?

    <p>2 in.</p> Signup and view all the answers

    What is the minimum distance between the lowest visible water level in the gauge glass and the lowest permissible water level in a horizontal firetube boiler with a diameter greater than 400 mm, according to ASME BPVC I Part PFT-47.1?

    <p>75 mm</p> Signup and view all the answers

    What is the minimum distance between the lowest visible water level in the gauge glass and the lowest permissible water level in a steam heating boiler, according to ASME BPVC IV Part HG-603?

    <p>25 mm</p> Signup and view all the answers

    What is the main reason for the failure of gauge glasses?

    <p>Corrosion caused by alkalinity and silica depletion at higher temperatures</p> Signup and view all the answers

    What should be done first when a gauge glass fails?

    <p>Shut off the steam and water valves on the gauge</p> Signup and view all the answers

    Why is it important to wear a face shield when replacing a gauge glass?

    <p>To protect against injury from fragments of glass</p> Signup and view all the answers

    What should be applied to the washers when installing a new gauge glass?

    <p>Graphite</p> Signup and view all the answers

    What should be installed on one side of the boiler?

    <p>New mica, new glass, and new cover and replace the nuts on the cover</p> Signup and view all the answers

    How should the nuts on the cover be tightened?

    <p>Tighten the nuts evenly starting from the centre of the glass</p> Signup and view all the answers

    What should be done with the gauge valves if the boiler is in service?

    <p>Do not open the gauge valves until the new glass is heated up</p> Signup and view all the answers

    What is the purpose of the bicolour gauge glass?

    <p>To show the steam and water levels as different colours</p> Signup and view all the answers

    What is indicated by the red light in a bicolour gauge glass?

    <p>The steam space in the boiler drum</p> Signup and view all the answers

    Why does the gauge glass generally indicate a water level lower than the actual level in the boiler drum?

    <p>Because the water in the gauge glass is cooler and denser than the water in the boiler drum</p> Signup and view all the answers

    What is the purpose of the mirrors in the bicolour gauge glass?

    <p>To reflect the red and green light to the operating floor</p> Signup and view all the answers

    What is required by ASME BPVC I Part PG-60.1.1.1?

    <p>A fibre optic cable or mirrors to transfer the optical image of the water level</p> Signup and view all the answers

    What is the purpose of cracking open the steam valve?

    <p>To slowly blow steam through to heat the glass further</p> Signup and view all the answers

    What should be done after the glass is at operating temperature?

    <p>Open the steam and water valves fully</p> Signup and view all the answers

    What is the purpose of the shutter in a coloured screen remote level indicator?

    <p>To separate the blue and red colours</p> Signup and view all the answers

    What is the purpose of the dirt traps in a remote level indicator?

    <p>To prevent contamination of the indicating liquid</p> Signup and view all the answers

    What is the advantage of an electronic remote water level indicator?

    <p>It has no moving mechanical parts</p> Signup and view all the answers

    What is the function of the water detection probes in a remote water level indicator?

    <p>To detect the presence of water or steam</p> Signup and view all the answers

    What is the purpose of the electronic detection and verification unit in a remote water level indicator?

    <p>To determine the validity of the reading and transmit the level to LED displays</p> Signup and view all the answers

    What is the purpose of the digital water level indicator in Figure 27?

    <p>To display the level on an LCD display in user-configurable engineering units</p> Signup and view all the answers

    What is the function of the camera in Figure 28?

    <p>To monitor the water levels and transmit the information to the control room</p> Signup and view all the answers

    What is the colour of the liquid in the manometer?

    <p>Blue or green</p> Signup and view all the answers

    What is the consequence of overfilling the indicating liquid in a remote level indicator?

    <p>The indicated level will be too high</p> Signup and view all the answers

    What is the function of the LED display in a remote water level indicator?

    <p>To display the level received from the electronic detection and verification unit</p> Signup and view all the answers

    What are the factors that can affect the error in a gauge glass?

    <p>Ambient temperature and length of the gauge glass</p> Signup and view all the answers

    Why is it important to keep piping connections to water level controls clear?

    <p>To ensure accurate water level readings</p> Signup and view all the answers

    What happens when steam connection piping is blocked?

    <p>Steam condenses and forms a vacuum</p> Signup and view all the answers

    Why is regular blowing down of the water column and gauge glass necessary?

    <p>To remove sediment that may collect</p> Signup and view all the answers

    What is the purpose of a remote water level indicator?

    <p>To show the water level at a remote location</p> Signup and view all the answers

    How often should the water column and gauge glass be blown down on smaller high-pressure boilers?

    <p>Every shift</p> Signup and view all the answers

    Why should gauge glasses be renewed?

    <p>If they become obscured by internal corrosion or deposits</p> Signup and view all the answers

    What is the purpose of ASME BPVC I Part PG-60.1.1.1?

    <p>To provide guidelines for remote water level indicators</p> Signup and view all the answers

    What is the operating element of the remote water level indicator in Figure 24?

    <p>A large sensitive diaphragm</p> Signup and view all the answers

    What happens when the water level in the drum rises in the remote water level indicator?

    <p>The diaphragm moves up</p> Signup and view all the answers

    What is the primary purpose of having a gauge glass in a boiler?

    <p>To continuously monitor the boiler water level</p> Signup and view all the answers

    Which of the following boilers is required to have a permanent indicator of the lowest permissible water level?

    <p>Heating boilers</p> Signup and view all the answers

    What is the minimum distance required between the lowest visible water level in a gauge glass and the lowest permissible water level in a power boiler?

    <p>2 in. (50 mm)</p> Signup and view all the answers

    What is the alternative to one of the required gauge glasses for boilers, according to ASME BPVC I Part PG-60.1.1.1?

    <p>Remote water level indicator</p> Signup and view all the answers

    What is the primary purpose of the valved fittings attached to the water column or boiler in a heating boiler?

    <p>To provide a way to attach the gauge glass</p> Signup and view all the answers

    What is the main purpose of the safety shutoff device in the lower valve on the gauge glass?

    <p>To prevent fluid from escaping when the gauge glass breaks</p> Signup and view all the answers

    What is the minimum diameter of the unrestricted drain opening required for steam heating boilers, according to ASME BPVC IV Part HG-603?

    <p>1/4 in. (6 mm)</p> Signup and view all the answers

    Why is it critical to know the boiler water level at all times, especially with boilers operating at higher pressures?

    <p>To prevent unsafe operation and potential damage to the boiler</p> Signup and view all the answers

    What is the purpose of the washer or packing ring and a nut at each end of the gauge glass tube?

    <p>To hold the gauge glass tube tightly in place</p> Signup and view all the answers

    What is the purpose of having both direct and indirect methods of determining the boiler water level?

    <p>To provide a redundant system for safety</p> Signup and view all the answers

    What determines the pressure ratings of gauge glass tubing?

    <p>All of the above</p> Signup and view all the answers

    What is the limitation of using tubular gauge glasses?

    <p>They are limited to relatively lower pressures and temperatures</p> Signup and view all the answers

    MEDIUM What is the purpose of the metal rods or transparent shield surrounding the gauge glass?

    <p>To protect the gauge glass from breakage</p> Signup and view all the answers

    What is the requirement for installing multiple gauge glasses?

    <p>The visible portions of the gauge glasses must overlap</p> Signup and view all the answers

    What is the purpose of the drain valve or cock on the lower gauge glass fitting?

    <p>To remove any solid material that may collect</p> Signup and view all the answers

    What is the minimum overlap required for adjoining sections of gauge glass assemblies?

    <p>1 in. (25 mm)</p> Signup and view all the answers

    What is the purpose of the isolating valves above and below the gauge glass connections?

    <p>To isolate the gauge glass for maintenance</p> Signup and view all the answers

    What is the purpose of the chains attached to the valve spindles?

    <p>To operate the valves from ground level if the boiler drum is located too high to reach</p> Signup and view all the answers

    Which type of boilers have a different requirement for the location of the gauge glass in relation to the lowest permissible water level?

    <p>Horizontal firetube boilers and locomotive boilers</p> Signup and view all the answers

    What is the main reason for the failure of tubular gauge glasses?

    <p>Corrosion caused by alkalinity and silica depletion</p> Signup and view all the answers

    What is the purpose of the water column in the installation shown in Figure 16?

    <p>To act as a reservoir to dampen agitation in the water</p> Signup and view all the answers

    What should be done first when a gauge glass fails?

    <p>Shut off the steam and water valves on the gauge</p> Signup and view all the answers

    What should be applied to the washers when installing a new gauge glass?

    <p>Graphite</p> Signup and view all the answers

    Why should the operator wear a face shield when replacing a gauge glass?

    <p>To prevent injury from flying glass fragments</p> Signup and view all the answers

    What is the purpose of the drain valve in the installation shown in Figure 15?

    <p>To permit all the connections to be blown through</p> Signup and view all the answers

    What is the requirement for the location of the gauge glass in relation to the lowest permissible water level in a steam heating boiler?

    <p>The lowest visible water level in the gauge glass must be at least 1 in. above the lowest permissible water level</p> Signup and view all the answers

    What is the purpose of the water column in relation to the gauge glass connections?

    <p>To trap sludge or sediment and prevent it from collecting in the gauge glass connections</p> Signup and view all the answers

    What is the requirement for tightening the nuts on the gauge glass?

    <p>The nuts should be only hand tightened</p> Signup and view all the answers

    What is the correct procedure for tightening the nuts on the cover?

    <p>Tighten the nuts on the cover evenly, starting from the centre of the glass.</p> Signup and view all the answers

    Why is it necessary to heat the gauge glass slowly when putting it into service?

    <p>To prevent the glass from breaking due to thermal shock</p> Signup and view all the answers

    What type of gauge glass is suitable for high pressure steam applications and can also be used for caustic and acidic liquids?

    <p>Armored-type (flat) gauge glass</p> Signup and view all the answers

    What is the purpose of allowing the new glass to warm up gradually in a boiler?

    <p>To prevent thermal shock to the glass.</p> Signup and view all the answers

    What should be done when the gauge glass leaks when put into service?

    <p>Close the steam and water valves, and open the drain before tightening the nuts</p> Signup and view all the answers

    What is the function of the green and red filters in a bicolour gauge glass?

    <p>To diffract the light and indicate the water level.</p> Signup and view all the answers

    Why is the gauge glass generally lower than the actual level in the boiler drum?

    <p>Because the water in the gauge glass is cooler and denser than the water in the boiler drum.</p> Signup and view all the answers

    What is the purpose of the mica coating on the inside surfaces of the glasses?

    <p>To provide a clear view of the liquid level</p> Signup and view all the answers

    What is the purpose of the mirrors in a bicolour gauge glass installation?

    <p>To direct the light from the gauge glass to the operator.</p> Signup and view all the answers

    Why should the operator wear a face shield when opening the valves?

    <p>To prevent injury from flying debris</p> Signup and view all the answers

    What is the correct sequence of steps when replacing the gauge glass in a boiler?

    <p>Install new glass, replace the cover, and tighten the nuts.</p> Signup and view all the answers

    What should be done when replacing the armored-type (flat) gauge glass?

    <p>Apply molybdenum disulfide to the threads of the studs</p> Signup and view all the answers

    What is the limitation of using tubular gauge glasses?

    <p>They are not suitable for high pressure steam applications</p> Signup and view all the answers

    What is the purpose of cracking open the steam valve during the replacement of the gauge glass?

    <p>To heat the new glass further.</p> Signup and view all the answers

    What happens when the mica coating on the inside surfaces of the glasses becomes opaque?

    <p>Water is now directly contacting the glass</p> Signup and view all the answers

    What is the purpose of the circulating tie bar in a bicolour gauge glass?

    <p>To provide a connection point for the gauge valves.</p> Signup and view all the answers

    What is the requirement for indicating the drum level in a boiler with a gauge glass?

    <p>The gauge glass must be visible from the operating floor.</p> Signup and view all the answers

    What should be done when checking the gauge glass for level?

    <p>Wait for the water level to stabilize</p> Signup and view all the answers

    What is the purpose of the reflex gauge?

    <p>To create a sharp line of demarcation at the liquid level</p> Signup and view all the answers

    What is the purpose of the water valve in the installation of a new gauge glass?

    <p>To allow water to enter the boiler.</p> Signup and view all the answers

    What is the purpose of the shutter in a coloured screen remote level indicator?

    <p>To separate the blue and red colours</p> Signup and view all the answers

    What is the function of the dirt traps in a remote level indicator?

    <p>To prevent contamination of the indicating liquid</p> Signup and view all the answers

    What type of liquid is used in the manometer of a remote level indicator?

    <p>Insoluble liquid denser than water</p> Signup and view all the answers

    What is the advantage of using an electronic remote water level indicator?

    <p>It has no moving mechanical parts</p> Signup and view all the answers

    What is the purpose of the LED displays in a remote water level indicator?

    <p>To display the water level reading</p> Signup and view all the answers

    What is the effect of a closed valve on the steam connection piping?

    <p>The steam in the gauge glass condenses, forming a vacuum.</p> Signup and view all the answers

    What is the result of a blocked water connection piping?

    <p>The condensate accumulates in the float cage, column, or gauge glass.</p> Signup and view all the answers

    What is the purpose of the cameras in a remote water level indicator?

    <p>To monitor the water level and transmit the information to the control room</p> Signup and view all the answers

    What is the unit of measurement displayed on the digital water level indicator in Figure 27?

    <p>Millimetres</p> Signup and view all the answers

    Why is it necessary to keep piping connections to water level controls, water columns, and gauge glasses clear?

    <p>To ensure accurate communication of the boiler water level to the level instruments.</p> Signup and view all the answers

    What is the purpose of blowing down the water column and gauge glass?

    <p>To remove sediment that may collect.</p> Signup and view all the answers

    What happens when the drum level rises in a coloured screen remote level indicator?

    <p>The shutter moves upwards</p> Signup and view all the answers

    What is the purpose of the water column in a remote water level indicator?

    <p>To connect the steam condenser to the boiler</p> Signup and view all the answers

    What is the recommended frequency of blowing down the gauge glass on large boilers?

    <p>Less frequently, to avoid shortening the life of the mica.</p> Signup and view all the answers

    What is the purpose of remote water level indicators?

    <p>To show the water level at a remote location.</p> Signup and view all the answers

    What is the function of the probes in a remote water level indicator?

    <p>To detect the presence of water or steam</p> Signup and view all the answers

    What is the operating principle of the mechanical remote water level indicator shown in Figure 24?

    <p>It uses a spring to balance the pressure on the two sides of the diaphragm.</p> Signup and view all the answers

    What is the effect of boiler pressure on the movement of the diaphragm in the mechanical remote water level indicator?

    <p>It has no effect on the movement of the diaphragm.</p> Signup and view all the answers

    What is required by ASME BPVC I Part PG-60.1.1.1 for boilers where the water level is not readily visible to the operator?

    <p>A combination of two of the following: an independent remote water level indicator, an independent continuous transmission and display of an image of the water level, or a fiber optic cable.</p> Signup and view all the answers

    What is the purpose of regular water column, gauge glass, and level control blow down?

    <p>To remove sediment that may collect and ensure accurate communication of the boiler water level.</p> Signup and view all the answers

    HARD What is the minimum number of gage glasses required for boilers with a maximum allowable working pressure not exceeding 400 psi, according to ASME BPVC I Part PG-60.1?

    <p>One</p> Signup and view all the answers

    What is the purpose of the drain valve in the lower fitting of the gage glass on a steam heating boiler, according to ASME BPVC IV Part HG-603?

    <p>To facilitate cleaning</p> Signup and view all the answers

    What is the minimum diameter of the unrestricted drain opening required for steam heating boilers, according to ASME BPVC IV Part HG-603?

    <p>¼ in.</p> Signup and view all the answers

    What is the alternative to one of the required gage glasses for boilers, according to ASME BPVC I Part PG-60.1.1.1?

    <p>A remote water level indicator</p> Signup and view all the answers

    What is the minimum distance required between the lowest visible water level in a gage glass and the lowest permissible water level, according to ASME BPVC IV Part HG-603?

    <p>1 in.</p> Signup and view all the answers

    What is the purpose of the valved fittings attached to the water column or boiler on a steam heating boiler, according to ASME BPVC IV Part HG-603?

    <p>To attach the gage glass</p> Signup and view all the answers

    What is required by ASME BPVC I Part PG-60.1 for boilers having a maximum allowable working pressure exceeding 400 psi?

    <p>Two gage glasses</p> Signup and view all the answers

    What is the purpose of the permanent indicator of the lowest permissible water level on a steam heating boiler?

    <p>To indicate the lowest permissible water level</p> Signup and view all the answers

    What is the recommended procedure for tightening the bolts on a transparent gauge glass?

    <p>Tightening the bolts from the centre outwards</p> Signup and view all the answers

    What is the purpose of the mica coating on the inside surfaces of the glasses in a transparent gauge glass?

    <p>To prevent water from contacting the glass</p> Signup and view all the answers

    Why must the gauge glass be inserted into the steam fitting first and then lowered into the bottom of the water fitting before tightening the nuts?

    <p>To ensure the glass is properly aligned</p> Signup and view all the answers

    What is the primary purpose of a reflex gauge glass?

    <p>To create a sharp line of demarcation at the liquid level</p> Signup and view all the answers

    What should be done before tightening the nuts on a gauge glass that has been replaced?

    <p>Apply molybdenum disulfide to the contact surfaces</p> Signup and view all the answers

    What is the primary advantage of using a flat gauge glass?

    <p>It is suitable for high-pressure steam applications</p> Signup and view all the answers

    Why should the operator wear a face shield when opening the valves?

    <p>To prevent injury from sudden valve opening</p> Signup and view all the answers

    What is the purpose of the crossover method of tightening the bolts on a transparent gauge glass?

    <p>To ensure even pressure on the glass</p> Signup and view all the answers

    What should be done when a gauge glass leaks during initial installation?

    <p>Close the steam and water valves and open the drain</p> Signup and view all the answers

    What is the primary purpose of polishing the gauge surfaces when replacing a gauge glass?

    <p>To ensure the gasket material does not plug the valves</p> Signup and view all the answers

    What is the main reason for the requirement of a greater safety margin for power boiler water level indicators as opposed to those for heating boilers?

    <p>Due to the higher operating pressure of power boilers</p> Signup and view all the answers

    What is the purpose of the water column in the installation shown in Figure 16?

    <p>To act as a reservoir to dampen agitation in the water</p> Signup and view all the answers

    What is the consequence of misalignment of fittings on the gauge glass?

    <p>It causes premature gauge glass failure</p> Signup and view all the answers

    What is the recommended method for cutting a new gauge glass to the correct length?

    <p>Using a glass cutter</p> Signup and view all the answers

    What is the purpose of putting graphite on the washers when installing a new gauge glass?

    <p>To act as a lubricant between the washers and nuts</p> Signup and view all the answers

    What is the requirement for the location of the gauge glass in relation to the lowest permissible water level in a horizontal firetube boiler with a diameter greater than 400 mm?

    <p>The lowest visible water level in the gauge glass must be at least 75 mm above the lowest permissible water level</p> Signup and view all the answers

    What is the purpose of the drain valve on the gauge glass fitting?

    <p>To permit all the connections to be blown through</p> Signup and view all the answers

    Why should the nuts on the gauge glass be tightened alternately?

    <p>To prevent the glass from turning when tightening the nuts</p> Signup and view all the answers

    What is the consequence of not cracking open the gauge glass valves when replacing a gauge glass?

    <p>The gauge glass may shatter due to fragments of glass</p> Signup and view all the answers

    What is the purpose of the water column in relation to the gauge glass connections?

    <p>To trap sludge or sediment in the gauge glass connections</p> Signup and view all the answers

    What is the main reason why the gauge glass generally indicates a water level lower than the actual level in the boiler drum?

    <p>The density of the water in the gauge glass is higher than the density of the water in the boiler drum.</p> Signup and view all the answers

    What is the purpose of cracking open the steam valve?

    <p>To allow the new glass to warm up gradually.</p> Signup and view all the answers

    What is the purpose of the mirrors in the bicolour gauge glass?

    <p>To reflect the red and green light to the control area.</p> Signup and view all the answers

    What is required by ASME BPVC I Part PG-60.1.1.1?

    <p>A fibre optic cable or mirrors must be used to transfer the optical image of the water level to the control area.</p> Signup and view all the answers

    What is the purpose of the bicolour gauge glass?

    <p>To indicate the steam and water levels separately.</p> Signup and view all the answers

    Why is it important to allow the new glass to warm up gradually?

    <p>To prevent the glass from breaking.</p> Signup and view all the answers

    What is the purpose of the green light in a bicolour gauge glass?

    <p>To indicate the water level in the boiler.</p> Signup and view all the answers

    How should the nuts on the cover be tightened?

    <p>Tighten the nuts on the cover starting from the centre of the glass.</p> Signup and view all the answers

    What should be done after the glass is at operating temperature?

    <p>Close the drain valve and open the steam valve.</p> Signup and view all the answers

    Why should the old gauge glasses not be reused?

    <p>All of the above.</p> Signup and view all the answers

    What is the effect of a blocked steam connection piping on the water level in the gauge glass?

    <p>The steam in the gauge glass will condense, forming a vacuum that draws water in, causing the operators to believe the boiler is full of water.</p> Signup and view all the answers

    Why is it necessary to blow down the water column and gauge glass regularly?

    <p>To remove sediment that may collect and affect the water level reading.</p> Signup and view all the answers

    What is the purpose of the condenser at the boiler drum in a remote water level indicator?

    <p>To maintain a constant head of water pressure on the steam side.</p> Signup and view all the answers

    What is the result of a blocked water connection piping on the steam in the gauge glass?

    <p>The steam will condense and accumulate in the float cage, column, or gauge glass.</p> Signup and view all the answers

    What is the purpose of the mica coating on the inside surfaces of the gauge glasses?

    <p>To protect the gauge glass from internal corrosion or deposits.</p> Signup and view all the answers

    Why is it necessary to keep the piping connections to water level controls, water columns, and gauge glasses clear?

    <p>To ensure the boiler water level is properly communicated to the level instruments.</p> Signup and view all the answers

    What is the consequence of not blowing down the water column and gauge glass regularly?

    <p>The water level reading will be inaccurate due to sediment accumulation.</p> Signup and view all the answers

    What is the purpose of the spring in a remote water level indicator?

    <p>To balance the difference in head pressure on the two sides of the diaphragm.</p> Signup and view all the answers

    What is the result of a closed valve on the water level control piping?

    <p>The steam in the gauge glass will condense and form a vacuum that draws water in.</p> Signup and view all the answers

    What is the requirement for installing multiple gauge glasses, according to ASME BPVC I Part PG-60.1.1.1?

    <p>A combination of two of the above options shall be provided.</p> Signup and view all the answers

    What is the purpose of the transparent leg in a manometer-based remote level indicator?

    <p>To provide a constant head of water acting on one leg of the manometer</p> Signup and view all the answers

    What is the advantage of using an electronic remote water level indicator?

    <p>It has no moving mechanical parts</p> Signup and view all the answers

    What is the purpose of the shutter in a coloured screen remote level indicator?

    <p>To separate the blue and red colours in the indicator</p> Signup and view all the answers

    What is the function of the detection and verification unit in an electronic remote water level indicator?

    <p>To determine the validity of the reading and transmit the level to LED displays</p> Signup and view all the answers

    What is the purpose of the digital water level indicator shown in Figure 27?

    <p>To display the level in user-configurable engineering units</p> Signup and view all the answers

    What is the advantage of using a remote water level indicator with multiple displays?

    <p>It can be located up to three different locations</p> Signup and view all the answers

    What is the purpose of the cameras in the remote water level indicator system shown in Figure 28?

    <p>To monitor the water levels and transmit the information to the control room</p> Signup and view all the answers

    What is the consequence of overfilling the indicating liquid in a manometer-based remote level indicator?

    <p>The indicated level will be too high</p> Signup and view all the answers

    What is the purpose of the dirt traps in a manometer-based remote level indicator?

    <p>To prevent contamination of the indicating liquid</p> Signup and view all the answers

    What is the function of the probes in an electronic remote water level indicator?

    <p>To detect the presence of water or steam in the boiler</p> Signup and view all the answers

    What is the purpose of the stainless steel check ball in the lower valve on the gauge glass?

    <p>To stop the flow of fluid in case the gauge glass breaks</p> Signup and view all the answers

    Why are tubular gauge glasses limited to relatively lower pressures and temperatures?

    <p>Because their pressure ratings are determined by the manufacturer</p> Signup and view all the answers

    What is the minimum overlap required for adjoining sections of gauge glass assemblies?

    <p>1 in. (25 mm)</p> Signup and view all the answers

    What determines the pressure ratings of gauge glass tubing?

    <p>All of the above</p> Signup and view all the answers

    Why are metal rods or a transparent shield used to surround the gauge glass?

    <p>To protect the gauge glass from breakage</p> Signup and view all the answers

    What is the purpose of the washers or packing rings and nuts at each end of the gauge glass tube?

    <p>To hold the gauge glass tightly in place</p> Signup and view all the answers

    What is the minimum size of piping required for connecting a water column to a steam boiler?

    <p>NPS 1 (DN 25)</p> Signup and view all the answers

    What is the purpose of the drain valve or cock on the lower gauge glass fitting?

    <p>To remove solid material that may collect</p> Signup and view all the answers

    What is the limitation of using tubular gauge glasses?

    <p>They are limited to relatively lower pressures and temperatures</p> Signup and view all the answers

    What is the purpose of the valved fittings attached to the water column or boiler?

    <p>To blow down the water column</p> Signup and view all the answers

    Study Notes

    Boiler Water Level Measurement

    • Boiler water level can be measured using direct or indirect methods.
    • Direct methods include gauge glasses of various designs.
    • Indirect methods include remote water level indicators.

    ASME BPVC Code Requirements

    • ASME BPVC I Part PG-60.1 requires at least one gauge glass for boilers with a fixed water level.
    • Boilers with a maximum allowable working pressure exceeding 400 psi (3 MPa) require two gauge glasses.
    • The lowest visible water level in a gauge glass must be at least 2 in. (50 mm) above the lowest permissible water level.
    • ASME BPVC I Part PG-60.1.1.1 allows for the use of remote water level indicators.

    Gauge Glass Types

    • Tubular gauge glasses:
      • Simplest and least costly design.
      • Limited to relatively lower pressures and temperatures.
      • Excessively long gauge glasses should be avoided.
    • Armored-type (flat) gauge glasses:
      • Used for higher pressures and temperatures.
      • Consist of glass plates bolted in a steel forged housing.
    • Bicolour gauge glasses:
      • Show steam and water as different colours.
      • Permit easy identification of the water level at a distance.

    Gauge Glass Installation and Maintenance

    • Gauge glasses can be connected directly to the shell or drum of the boiler, or to an intervening water column.
    • ASME BPVC I Part PG-60.3.1 and BPVC IV Part HG-603 permit gauge glasses to be connected to a single water column.
    • Gauge glasses should be replaced if they become corroded or damaged.
    • Replacement of tubular gauge glasses involves shutting off steam and water valves, opening the drain valve, and removing the broken glass.

    Error in Gauge Glass Measurement

    • Gauge glasses generally indicate a water level lower than the actual level in the boiler drum.
    • Error is affected by factors such as ambient temperature, length of the gauge glass, and level of the liquid in the gauge glass.

    Testing of Water Column and Gauge Glass During Operation

    • Water and steam connections to both a water column and a gauge glass must always be unobstructed.

    • Regular water column, gauge glass, and level control blow down is recommended to remove sediment and ensure accurate water level measurement.### Remote Water Level Indicators

    • Remote water level indicators are used to show the water level at a remote location, such as in a control room, adjacent to boiler blowoff valves, or at particular operating locations.

    ASME BPVC I Part PG-60.1.1.1 Requirements

    • When the water level in at least one gage glass is not readily visible to the operator in the area where control actions are initiated, a remote water level indicator is required.
    • The indicator can be a fiber optic cable, mirrors, or a combination of two of the following: an independent remote water level indicator, and an independent continuous transmission and display of an image of the water level in a gage glass.

    Mechanical Remote Water Level Indicators

    • Figure 24 shows a type of remote water level indicator of entirely mechanical operation.
    • The operating element consists of a large sensitive diaphragm with the top side connected to the steam space of the boiler, and the bottom to the water space.
    • The diaphragm moves up and down in accordance with the water level.
    • Coloured screens illuminate the inside of the indicator with blue in the lower portion, representing the water, and red in the upper part to represent steam.

    Manometer Remote Water Level Indicators

    • Figure 25 shows a type of remote level indicator that is basically a manometer with one transparent leg.
    • The manometer is filled with a blue or green insoluble liquid that is denser than water.
    • The indicating liquid rises in the glass, and shows the level to engineers on the operating floor as the drum level rises.

    Electronic Remote Water Level Indicators

    • Figure 26 shows a common type of remote water level indicator that uses electronic devices to sense and transmit level.
    • The system is comprised of three major components: a water column with up to 24 water detection probes, an electronic detection and verification unit, and one or more remote LED displays.
    • The probes detect the presence of water or steam, and the detection and verification unit determines the validity of the reading, and transmits the level to LED displays.

    Digital Water Level Indicators

    • Figure 27 shows a digital water level indicator that receives a standard 4 to 20 mA signal from a drum level transmitter, and displays the level on an LCD display, in user-configurable engineering units.
    • The indicator shows drum level in millimetres, with levels above or below set point indicated as positive or negative readings.

    Remote Water Level Indicators in Control Rooms

    • Figure 28 shows four reflex-type gauge glasses for four different boilers, displayed on a single computer display, in a central control room.
    • Cameras monitor the water levels and transmit the information to the control room in real time.

    ASME BPVC I Part PG-60.1.1.2 Requirements

    • The display of a remote water level indicator shall have a clearly marked minimum water level reference at least 2 in.(50 mm) above the lowest permissible water level, as determined by the Manufacturer.

    Boiler Water Level Measurement

    • Boiler water level can be measured using direct or indirect methods.
    • Direct methods include gauge glasses of various designs.
    • Indirect methods include remote water level indicators.

    ASME BPVC Code Requirements

    • ASME BPVC I Part PG-60.1 requires at least one gauge glass for boilers with a fixed water level.
    • Boilers with a maximum allowable working pressure exceeding 400 psi (3 MPa) require two gauge glasses.
    • The lowest visible water level in a gauge glass must be at least 2 in. (50 mm) above the lowest permissible water level.
    • ASME BPVC I Part PG-60.1.1.1 allows for the use of remote water level indicators.

    Gauge Glass Types

    • Tubular gauge glasses:
      • Simplest and least costly design.
      • Limited to relatively lower pressures and temperatures.
      • Excessively long gauge glasses should be avoided.
    • Armored-type (flat) gauge glasses:
      • Used for higher pressures and temperatures.
      • Consist of glass plates bolted in a steel forged housing.
    • Bicolour gauge glasses:
      • Show steam and water as different colours.
      • Permit easy identification of the water level at a distance.

    Gauge Glass Installation and Maintenance

    • Gauge glasses can be connected directly to the shell or drum of the boiler, or to an intervening water column.
    • ASME BPVC I Part PG-60.3.1 and BPVC IV Part HG-603 permit gauge glasses to be connected to a single water column.
    • Gauge glasses should be replaced if they become corroded or damaged.
    • Replacement of tubular gauge glasses involves shutting off steam and water valves, opening the drain valve, and removing the broken glass.

    Error in Gauge Glass Measurement

    • Gauge glasses generally indicate a water level lower than the actual level in the boiler drum.
    • Error is affected by factors such as ambient temperature, length of the gauge glass, and level of the liquid in the gauge glass.

    Testing of Water Column and Gauge Glass During Operation

    • Water and steam connections to both a water column and a gauge glass must always be unobstructed.

    • Regular water column, gauge glass, and level control blow down is recommended to remove sediment and ensure accurate water level measurement.### Remote Water Level Indicators

    • Remote water level indicators are used to show the water level at a remote location, such as in a control room, adjacent to boiler blowoff valves, or at particular operating locations.

    ASME BPVC I Part PG-60.1.1.1 Requirements

    • When the water level in at least one gage glass is not readily visible to the operator in the area where control actions are initiated, a remote water level indicator is required.
    • The indicator can be a fiber optic cable, mirrors, or a combination of two of the following: an independent remote water level indicator, and an independent continuous transmission and display of an image of the water level in a gage glass.

    Mechanical Remote Water Level Indicators

    • Figure 24 shows a type of remote water level indicator of entirely mechanical operation.
    • The operating element consists of a large sensitive diaphragm with the top side connected to the steam space of the boiler, and the bottom to the water space.
    • The diaphragm moves up and down in accordance with the water level.
    • Coloured screens illuminate the inside of the indicator with blue in the lower portion, representing the water, and red in the upper part to represent steam.

    Manometer Remote Water Level Indicators

    • Figure 25 shows a type of remote level indicator that is basically a manometer with one transparent leg.
    • The manometer is filled with a blue or green insoluble liquid that is denser than water.
    • The indicating liquid rises in the glass, and shows the level to engineers on the operating floor as the drum level rises.

    Electronic Remote Water Level Indicators

    • Figure 26 shows a common type of remote water level indicator that uses electronic devices to sense and transmit level.
    • The system is comprised of three major components: a water column with up to 24 water detection probes, an electronic detection and verification unit, and one or more remote LED displays.
    • The probes detect the presence of water or steam, and the detection and verification unit determines the validity of the reading, and transmits the level to LED displays.

    Digital Water Level Indicators

    • Figure 27 shows a digital water level indicator that receives a standard 4 to 20 mA signal from a drum level transmitter, and displays the level on an LCD display, in user-configurable engineering units.
    • The indicator shows drum level in millimetres, with levels above or below set point indicated as positive or negative readings.

    Remote Water Level Indicators in Control Rooms

    • Figure 28 shows four reflex-type gauge glasses for four different boilers, displayed on a single computer display, in a central control room.
    • Cameras monitor the water levels and transmit the information to the control room in real time.

    ASME BPVC I Part PG-60.1.1.2 Requirements

    • The display of a remote water level indicator shall have a clearly marked minimum water level reference at least 2 in.(50 mm) above the lowest permissible water level, as determined by the Manufacturer.

    Boiler Water Level Measurement

    • Boiler water level can be measured using direct or indirect methods.
    • Direct methods include gauge glasses of various designs.
    • Indirect methods include remote water level indicators.

    ASME BPVC Code Requirements

    • ASME BPVC I Part PG-60.1 requires at least one gauge glass for boilers with a fixed water level.
    • Boilers with a maximum allowable working pressure exceeding 400 psi (3 MPa) require two gauge glasses.
    • The lowest visible water level in a gauge glass must be at least 2 in. (50 mm) above the lowest permissible water level.
    • ASME BPVC I Part PG-60.1.1.1 allows for the use of remote water level indicators.

    Gauge Glass Types

    • Tubular gauge glasses:
      • Simplest and least costly design.
      • Limited to relatively lower pressures and temperatures.
      • Excessively long gauge glasses should be avoided.
    • Armored-type (flat) gauge glasses:
      • Used for higher pressures and temperatures.
      • Consist of glass plates bolted in a steel forged housing.
    • Bicolour gauge glasses:
      • Show steam and water as different colours.
      • Permit easy identification of the water level at a distance.

    Gauge Glass Installation and Maintenance

    • Gauge glasses can be connected directly to the shell or drum of the boiler, or to an intervening water column.
    • ASME BPVC I Part PG-60.3.1 and BPVC IV Part HG-603 permit gauge glasses to be connected to a single water column.
    • Gauge glasses should be replaced if they become corroded or damaged.
    • Replacement of tubular gauge glasses involves shutting off steam and water valves, opening the drain valve, and removing the broken glass.

    Error in Gauge Glass Measurement

    • Gauge glasses generally indicate a water level lower than the actual level in the boiler drum.
    • Error is affected by factors such as ambient temperature, length of the gauge glass, and level of the liquid in the gauge glass.

    Testing of Water Column and Gauge Glass During Operation

    • Water and steam connections to both a water column and a gauge glass must always be unobstructed.

    • Regular water column, gauge glass, and level control blow down is recommended to remove sediment and ensure accurate water level measurement.### Remote Water Level Indicators

    • Remote water level indicators are used to show the water level at a remote location, such as in a control room, adjacent to boiler blowoff valves, or at particular operating locations.

    ASME BPVC I Part PG-60.1.1.1 Requirements

    • When the water level in at least one gage glass is not readily visible to the operator in the area where control actions are initiated, a remote water level indicator is required.
    • The indicator can be a fiber optic cable, mirrors, or a combination of two of the following: an independent remote water level indicator, and an independent continuous transmission and display of an image of the water level in a gage glass.

    Mechanical Remote Water Level Indicators

    • Figure 24 shows a type of remote water level indicator of entirely mechanical operation.
    • The operating element consists of a large sensitive diaphragm with the top side connected to the steam space of the boiler, and the bottom to the water space.
    • The diaphragm moves up and down in accordance with the water level.
    • Coloured screens illuminate the inside of the indicator with blue in the lower portion, representing the water, and red in the upper part to represent steam.

    Manometer Remote Water Level Indicators

    • Figure 25 shows a type of remote level indicator that is basically a manometer with one transparent leg.
    • The manometer is filled with a blue or green insoluble liquid that is denser than water.
    • The indicating liquid rises in the glass, and shows the level to engineers on the operating floor as the drum level rises.

    Electronic Remote Water Level Indicators

    • Figure 26 shows a common type of remote water level indicator that uses electronic devices to sense and transmit level.
    • The system is comprised of three major components: a water column with up to 24 water detection probes, an electronic detection and verification unit, and one or more remote LED displays.
    • The probes detect the presence of water or steam, and the detection and verification unit determines the validity of the reading, and transmits the level to LED displays.

    Digital Water Level Indicators

    • Figure 27 shows a digital water level indicator that receives a standard 4 to 20 mA signal from a drum level transmitter, and displays the level on an LCD display, in user-configurable engineering units.
    • The indicator shows drum level in millimetres, with levels above or below set point indicated as positive or negative readings.

    Remote Water Level Indicators in Control Rooms

    • Figure 28 shows four reflex-type gauge glasses for four different boilers, displayed on a single computer display, in a central control room.
    • Cameras monitor the water levels and transmit the information to the control room in real time.

    ASME BPVC I Part PG-60.1.1.2 Requirements

    • The display of a remote water level indicator shall have a clearly marked minimum water level reference at least 2 in.(50 mm) above the lowest permissible water level, as determined by the Manufacturer.

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    Description

    Learn about the methods of measuring boiler water level, including direct and indirect methods, and the ASME BPVC code requirements for gauge glasses on boilers.

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