3RD CLASS POWER ENGINEERING - B1
- PART 1 QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS 100%
CORRECT!!!
Flat Type Gauge Glasses
✔✔ Answer:
Designed for use with higher steam pressures
Made with thick glass plates secured inside a forged steel frame
The glass surfaces are protected with mica lining to reduce damage caused
by steam and water etching
Gaskets are installed between the covers to prevent stress or cracking when
the covers are tightened
Steps for Testing a Gauge Glass and Water Column
✔✔ Answer:
1. Isolate both the steam and water sides of the gauge glass before inspecting
the column connections.
2. Shut the bottom water valve on the column and open the drain valve. This
allows steam to pass through the steam connection and confirms there are no
blockages. Then close the drain valve.
3. Close the top steam valve, open the bottom water valve, and reopen the drain
valve. This checks that the water connection is clear.
4. Close the drain valve and reopen the top steam valve to return the column to
normal operation.
5. Open the top steam valve on the gauge glass along with the drain valve.
Steam passing through confirms the top connection is unobstructed. Then
close the drain valve.
, 6. Close the steam valve, open the water valve, and then open the drain valve.
Water flowing through verifies the water connection is clear.
7. Close the drain valve and reopen the steam valve to place the gauge glass
back into service.
Code for boilers not continuously attended by a certified operator? -ANSWER
✔✔- Shall be equipped with 2 low water fuel cut off devices each of which shall
be independent of each other or others
- Shall be installed so they cannot be rendered inoperative
- Shall be installed so they can be tested under operation conditions, by means of a
fuel shut-off or an interruption of energy source for electric boilers
Some manufacturers or jurisdictions require low water fuel cutoffs to be tested at
least monthly or even weekly. True or False? -ANSWER ✔✔True
Gate Stop Valves? -ANSWER ✔✔- Handwheel is carried on the yoke and does not
rise with the spindle
- Locking lugs secure the bonnet to the valve body and are engaged by lowering
the bonnet into the body and turning 45 degrees
- Bonnet is then seal welded to the body
- The steel ring below the seal weld prevents stress at the bonnet joint due to
welding
Globe type Stop Valves? -ANSWER ✔✔- Outside screw and yoke design with a
rising spindle AND rising hand-wheel (hand-wheel attached to spindle)
- Valve disc sits in a replaceable seat
- Steam flows up from the bottom and passes between the valve disc and the seat
- Excellent for throttling or for flow control applications
,Purpose of the Non Return Valve? -ANSWER ✔✔- The purpose of the non return
valve is to prevent a back flow of steam if failure occurs somewhere inside that
boiler.
- Non return valves also make it easier to bring a boiler online when its supporting
a common header with other boilers. The stem of the non return valve can be put in
the open position before the boiler is up to pressure
- Non return valves allow the shutdown and startup of a boiler without the need to
operate the manual stop valve
Y-Type Non-Return Valves? -ANSWER ✔✔- Very similar to the Globe Non
Return valve but is installed at an angle in the piping system usually by welding
- Uses an equalizing connection to prevent reverse flow of steam identical to non
return valve
Angle Non-Return Valve? -ANSWER ✔✔- Valve disc is attached to a piston,
which works within a cylinder
- When the valve spindle is backed off, the piston is free to move
- Valve may be secured in the closed position by turning the spindle down against
the disc
- The piston serves to cushion the action of the valve when opening
- Angle valves leaves the drum vertically and then exit the valve at 90 degrees
horizontally
A common arrangement would be:
- A Non Return valve closest to the boiler
- A Stop valve at the header
- Drain valves in drain the piping in between these 2 valves
, True or False? -ANSWER ✔✔True.
Codes for Blowoff Connections? -ANSWER ✔✔- " The minimum size for blowoff
connections shall be NPS 1 and the maximum size shall be NPS 2 1/2 "
- " A bottom blowoff pipe when exposed to direct furnace heat shall be protected
by firebrick or other heat resistant material "
4 most common Blowoff Valves? -ANSWER ✔✔- Sliding disc
- Seatless sliding plunger
- Seat and disc
- Combination
Sliding Disc Blowoff Valves? -ANSWER ✔✔- When open, disc moves to one side
creating a passage. When closed, disc covers the opening
- Must always be used in conjunction with a slow opening valve, unless the sliding
disc valve itself is made into a slow opening valve
- Moving the lever through less than 90 degrees operates the valve from full open
to full closed
Seat and Disc Blowoff Valves? -ANSWER ✔✔- Slow opening valves which
feature a rotating, rising stem with an attached disc on the bottom
- Disc is free to rotate and mates with the valve seat in the body
- The valve sear surfaces are protected from erosion by using hard materials such
as Monel or Stellite
- Seats are also threaded for easy replacement
- Comes in Angle Types and Y-Types
- PART 1 QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS 100%
CORRECT!!!
Flat Type Gauge Glasses
✔✔ Answer:
Designed for use with higher steam pressures
Made with thick glass plates secured inside a forged steel frame
The glass surfaces are protected with mica lining to reduce damage caused
by steam and water etching
Gaskets are installed between the covers to prevent stress or cracking when
the covers are tightened
Steps for Testing a Gauge Glass and Water Column
✔✔ Answer:
1. Isolate both the steam and water sides of the gauge glass before inspecting
the column connections.
2. Shut the bottom water valve on the column and open the drain valve. This
allows steam to pass through the steam connection and confirms there are no
blockages. Then close the drain valve.
3. Close the top steam valve, open the bottom water valve, and reopen the drain
valve. This checks that the water connection is clear.
4. Close the drain valve and reopen the top steam valve to return the column to
normal operation.
5. Open the top steam valve on the gauge glass along with the drain valve.
Steam passing through confirms the top connection is unobstructed. Then
close the drain valve.
, 6. Close the steam valve, open the water valve, and then open the drain valve.
Water flowing through verifies the water connection is clear.
7. Close the drain valve and reopen the steam valve to place the gauge glass
back into service.
Code for boilers not continuously attended by a certified operator? -ANSWER
✔✔- Shall be equipped with 2 low water fuel cut off devices each of which shall
be independent of each other or others
- Shall be installed so they cannot be rendered inoperative
- Shall be installed so they can be tested under operation conditions, by means of a
fuel shut-off or an interruption of energy source for electric boilers
Some manufacturers or jurisdictions require low water fuel cutoffs to be tested at
least monthly or even weekly. True or False? -ANSWER ✔✔True
Gate Stop Valves? -ANSWER ✔✔- Handwheel is carried on the yoke and does not
rise with the spindle
- Locking lugs secure the bonnet to the valve body and are engaged by lowering
the bonnet into the body and turning 45 degrees
- Bonnet is then seal welded to the body
- The steel ring below the seal weld prevents stress at the bonnet joint due to
welding
Globe type Stop Valves? -ANSWER ✔✔- Outside screw and yoke design with a
rising spindle AND rising hand-wheel (hand-wheel attached to spindle)
- Valve disc sits in a replaceable seat
- Steam flows up from the bottom and passes between the valve disc and the seat
- Excellent for throttling or for flow control applications
,Purpose of the Non Return Valve? -ANSWER ✔✔- The purpose of the non return
valve is to prevent a back flow of steam if failure occurs somewhere inside that
boiler.
- Non return valves also make it easier to bring a boiler online when its supporting
a common header with other boilers. The stem of the non return valve can be put in
the open position before the boiler is up to pressure
- Non return valves allow the shutdown and startup of a boiler without the need to
operate the manual stop valve
Y-Type Non-Return Valves? -ANSWER ✔✔- Very similar to the Globe Non
Return valve but is installed at an angle in the piping system usually by welding
- Uses an equalizing connection to prevent reverse flow of steam identical to non
return valve
Angle Non-Return Valve? -ANSWER ✔✔- Valve disc is attached to a piston,
which works within a cylinder
- When the valve spindle is backed off, the piston is free to move
- Valve may be secured in the closed position by turning the spindle down against
the disc
- The piston serves to cushion the action of the valve when opening
- Angle valves leaves the drum vertically and then exit the valve at 90 degrees
horizontally
A common arrangement would be:
- A Non Return valve closest to the boiler
- A Stop valve at the header
- Drain valves in drain the piping in between these 2 valves
, True or False? -ANSWER ✔✔True.
Codes for Blowoff Connections? -ANSWER ✔✔- " The minimum size for blowoff
connections shall be NPS 1 and the maximum size shall be NPS 2 1/2 "
- " A bottom blowoff pipe when exposed to direct furnace heat shall be protected
by firebrick or other heat resistant material "
4 most common Blowoff Valves? -ANSWER ✔✔- Sliding disc
- Seatless sliding plunger
- Seat and disc
- Combination
Sliding Disc Blowoff Valves? -ANSWER ✔✔- When open, disc moves to one side
creating a passage. When closed, disc covers the opening
- Must always be used in conjunction with a slow opening valve, unless the sliding
disc valve itself is made into a slow opening valve
- Moving the lever through less than 90 degrees operates the valve from full open
to full closed
Seat and Disc Blowoff Valves? -ANSWER ✔✔- Slow opening valves which
feature a rotating, rising stem with an attached disc on the bottom
- Disc is free to rotate and mates with the valve seat in the body
- The valve sear surfaces are protected from erosion by using hard materials such
as Monel or Stellite
- Seats are also threaded for easy replacement
- Comes in Angle Types and Y-Types
