Pipe_6007_Specialized_Valves

Question 1: Pressure relief valves start to open at a preset pressure but require __________ overpressure to open wide.

A - 20% B - 15% C - 10% D - 5% _______________________________________________

Question 2: Blow-off valves are designed and installed in accordance with the __________ code in systems where blow-down _____________ is necessary.

A - ASME, rapid cooling B - ASME, drainage C - APPEGA, rapid cooling D - APPEGA, drainage _______________________________________________

Question 3: The type of blow-off valve used on high-pressure boilers is a:

A - Pressure safety valve B - Seat-and-disc valve C - Diaphragm valve D - Single seated balance valve _______________________________________________

Question 4: Some blowoff valves are made with integral seats made by depositing a hard-facing material, such as stellite, directly on the body of the valve. When such a seat starts to leak, the seating surface:

A - Is self-repairing as the stellite conforms to pressure variations B - Can be re-inserted while the valve remains in place in the pipeline C - Must be refaced immediately D - Can be re-cut or reground while the valve remains in place in the pipeline _______________________________________________

Question 5: A ________________________ is the best choice of valve for applications in which the process fluid is highly flammable, expensive, corrosive, toxic, or explosive and where tight shutoff is necessary.

A - Double-seated balance valve B - Double-ported valve C - Single-seated single-port balance valve D - Sliding-disc blow-off valve _______________________________________________

Question 6: Weight-operated balanced reducing valves are used to regulate pressure for:

A - Downstream only B - Upstream only C - Backpressure control only D - Both upstream and downstream _______________________________________________

Question 7: In a diaphragm valve, the mechanism that moves the diaphragm is completely ______________from the fluid and no __________________________ is required.

A - Integrated, valve wheel B - Integrated, packing material C - Separated, packing material D - Separated, valve wheel _______________________________________________

Question 8: The force required to position the plug of a pilot operated high pressure regulator is obtained from:

A - An external pilot unit and piston-type actuator B - An externally mounted compression spring C - An internal flexible diaphragm D - A thermostat which signals the spring-loaded closing element _______________________________________________

Question 9: When compared to a single-seated balance valve, a double-seated balance valve has greater difficulty in achieving tight shutoff because:

A - The double-seated valve usually has a smaller port area B - The temperature causes the stem to expand, increasing the distance between the plugs C - It can pass up to twice as much fluid as a single-seated valve D - More power is required to operate a double-seated valve _______________________________________________

Question 10: The bypass valve utilized in a pressure reducing station which throttles the flow during reducing valve maintenance should be a:

A - Gate valve B - Ball valve C - Butterfly valve D - Globe valve ______________________________________________

Question 11: For mixing fluids, the mixing valve is designed with:

A - One inlet and two discharge outlets B - One inlet, one discharge, and a drainage cock C - Two inlets and one discharge outlet D - Two inlets and two discharge outlets _______________________________________________

Question 12: Which type of valves are preferred for isolating the pressure reducing valve of a pressure reducing station? A - Globe valves B - Ball valves C - Gate valves D - Butterfly valves _______________________________________________

Question 13: The primary difference between pressure relief valves and pressure safety valves is that safety valves:

A - Pop wide open while relief valves open gradually B - Operate against a compression spring while relief valves do not C - Require 20% overpressure before they are fully open while relief valves are open at a set pressure D - Will close completely when the pressure drops to the opening pressure while relief valves will close before the opening pressure is reached _______________________________________________

Question 14: In an application where the process fluid is highly flammable, expensive, corrosive, toxic, or explosive and where tight shutoff is necessary, the best choice of balance valve is a:

A - Sliding-disc blowoff valve B - Double-seated balance valve C - Double-ported valve D - Single-seated single-port balance valve _______________________________________________

Question 15: For diverting fluids, the diverting valve is designed with:

A - One inlet, one discharge and a balancing pipe B - Two inlets and one discharge outlet C - One inlet and two discharge outlets D - Two inlets and two discharge outlets

_______________________________________________

Question 16: The outlet pressure of a spring-loaded internal diaphragm pressure-reducing valve can be lowered by:

A - Increasing the fluid flow in the control line to the diaphragm B - Turning the compression screw downward, into the bonnet C - Throttling the downstream pressure to the top of the diaphragm D - Reducing the compression of the valve spring _______________________________________________

Question 17: Safety valves provide a rapid means of getting rid of any excessive pressure before a serious accident occurs.

A - True B – False

_______________________________________________

Question 18: The rupture-disc relief valve is much like a diaphragm valve except that it has no bonnet but does have a control mechanism at the discharge.

A - True B - False _______________________________________________

Question 19: The outlet pressure of a spring-loaded internal diaphragm pressure reducing valve can be increased by:

A - Throttling the downstream pressure to the top of the diaphragm B - Increasing the fluid flow in the control line to the diaphragm C - Turning the screw downward increasing the spring compression D - Reducing the compression of the valve spring _______________________________________________

Question 20: A sliding-disc blow-off valve is used in combination with a:

A - Rupture disc B - Mixing valve C - Pressure reducing valve D - Slow-opening valve _______________________________________________

Question 21: Why is the diaphragm in this illustration not affected by the temperature of the fluid in a spring-loaded pressure-reducing valve?

A - Because the low-pressure suction draws the fluid away from the diaphragm B - because the diaphragm and spring are mounted outside the valve housing C - Because the valve is not equipped with a diaphragm D - Because the diaphragm is sealed behind the bearing