A try lever safety valve test will:
Ensure the valve is free to operate
Safety valves "pop" open because the force of the steam:
Is suddenly increased due to a larger area
The safety valves on a boiler meet code requirements and are set to a popping pressure of 1 380 kPa. What would be the maximum permissible pressure rise in the boiler if the boiler is fired at full capacity with the main steam stop valve closed?
82.8 kPa
The "popping" action of a safety valve is due to the:
Cone-shaped lip on the valve disc
What is the minimum number of safety valves required on a boiler having a heating surface of 42 m2?
One
The blowdown on a safety valve is adjusted by turning the:
Adjusting ring
What is the maximum heating surface for a boiler to have only one safety valve?
47 m�
If a safety valve fails to open at its popping pressure, you should:
Try the lifting lever
The lip on a safety valve:
Allows it to "pop" open
The popping pressure of a safety valve:
Can be increased or decreased by up to 5%
An operator should check that a boiler safety valve will open at its set pressure by:
Increasing the boiler pressure until the valve opens and noting the pressure on the pressure gauge when the valve opened
Each boiler must have a safety valve, preferably:
Fitted in a vertical position directly connected to the top of the boiler
The discharge pipe of a safety valve should be separately supported:
So that allowance for expansion prevents stress on the safety valve
A blowdown ring on a safety valve is used to:
Adjust the blow down differential
To increase the opening pressure of a safety valve:
Increase spring compression
The only person who can adjust the opening pressure or popping point of a safety valve is a/an:
Boiler inspector
When performing a safety valve pop test, one of the first things to do is:
Verify the accuracy of the applicable steam pressure gauge
Blowdown of a safety valve is defined as:
The difference between opening and closing pressures
The purpose of the spring in a safety valve is to:
Hold down the disc on the seat
To raise only the closing pressure of the valve, one would:
Screw the blowdown ring downwards
If a boiler has a maximum allowable working pressure of 1 000 kPa, what would be the maximum pressure allowed when the safety valve is open?
1 060 kPa
Temperature relief valves can open on a rise in temperature by the expansion of a wax-filled rod or by the:
Melting of the alloy in a fusible plug
If a safety valve is too small, then the boiler pressure will:
Rise more than 6% above the MAWP
If the boiler was fired up with the main steam stop valve closed, the safety valves should ensure that the:
:Pressure cannot exceed the maximum working pressure by more than 6%
Test levers on safety valves should not be used until the boiler pressure is at least _____ or more of the safety valve's normal popping pressure.
75%
A safety relief valve is like a safety valve except it:
Does not have a blowdown ring or bottom guides
What does the boiler inspector install to prevent tampering with a safety valve setting?
A seal
If a safety valve leaks after a try lever test, the operator should:
Operate the try lever several times to blow away foreign material
A stop valve is allowed between the safety valve and the boiler drum when:
No stop valves are allowed before or after the safety valve
If a boiler has 60 m� of heating surface, it must have _____ safety valves.
At least two
If, during the testing of a safety valve, the valve does not open, you would first:
Try to open the valve with the lifting lever
Testing the safety valve by means of the try lever method is considered good practice when carried out on a:
Monthly basis
Two safety valves are required on a high pressure steam boiler that has a heating surface larger than:
47 m�
If the safety valve starts to leak steam:
Pull the test lever and try to clear the seat face
A device which must be replaced each time it performs its function is the:
Rupture disk
If the safety valve on a steam heating boiler opens, what is the pressure above the maximum allowable working pressure that the boiler is allowed to rise?
35 kPa
LP boiler safety valves can be repaired:
By only the manufacturer
If you found the safety valve on your heating boiler stuck in the closed position while the boiler was in operation, the best thing to do is:
:Shut down the boiler and repair or replace the safety valve
According to the current code, the valve seat diameter of the safety valve on a steam heating boiler must not be smaller than:
13 mm (� in)
For a steam heating boiler, the safety valve shall be such that, with the fuel burning equipment installed and operated at maximum capacity, the pressure cannot rise more than _____ kPa above the maximum allowable working pressure when all steam outlets a
34
If a safety valve leaks after a try lever test, the operator should:
Operate the try lever several times to blow away foreign material
The steam heating boiler safety relief valve capacity for each boiler with a single safety relief valve shall be such that the pressure cannot rise more than _____ above the maximum allowable working pressure.
10%
On steam heating boilers, the safety valve test lever must not be used unless:
The boiler is at maximum pressure
According to the current code, no safety valve on a steam heating boiler shall be smaller than:
15 mm (� in)
Popping pressure of a steam heating boiler safety valve may be adjusted:
Pressure is up to at least 34 kPa
In order to ensure a safety valve seats properly, it uses:
Guides and bushings
Blowdown of a safety valve is defined as:
The difference between opening and closing pressures
The lip on a safety valve:
Allows it to "pop" open
According to the current the minimum blowdown for a steam heating boiler safety valve is:
14 kPa
The "popping" action of a safety valve is due to the:
Lip on the valve disc
To increase the opening pressure of a safety valve:
Increase spring compression
The blowdown on a safety valve is adjusted by turning the:
Adjusting ring
The safety valve shall be installed in the _____ position and located in the highest practicable part of the heating boiler proper.
Vertical
According to the current code, no safety valve on a steam heating boiler shall be larger than:
115 mm (4 � in)
A steam heating boiler safety valve lever test should be performed:
Monthly
Cast iron fittings used for water columns and valves of a steam boiler can be deemed to have upper limitations of:
1 720 kPa and 232�C