Question 21: Lean sour gas is a type of natural gas that: Has a low concentration of hydrogen sulfide
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Question 22: Which of the following natural gas components is considered a contaminant?
A - Hydrogen sulphide B - Helium C - Carbon dioxide D - Nitrogen _______________________________________________
Question 23: The formula C4H10represents:
A - Ethane B - Propane C - Butane D - Methane
PIPE 6010_Valve Actuators
Question 1: A solution to the high torque required to operate larger valves is to equip the valve with a gear system so that: A - The valve can be closed much tighter B - The position of the valve can be more precisely regulated C - The valve can be opened and closed much quicker than without a gear D - It is easier for the operator to open and close the valve _______________________________________________
Question 2: When it is desired to position the valve plug of a pneumatic piston actuator at any intermediate position a: A - Worm gear is required B - Positioner is required C - Solenoid is required D - Mechanical linkage system is required _______________________________________________
Question 3: A preloaded type actuator has a large air dome on top of the diaphragm which replaces the: A - Worm and gear B - Piston C - Coil D - Spring _______________________________________________
Question 4:
____________________ actuators are used when the force required to position a valve or damper is higher than that which can be provided by a diaphragm. A - Spring loaded diaphragm B - Pneumatic piston C - Mechanical D - Solenoid driven _______________________________________________
Question 5:Large motorized valves are equipped with limit switches: A - To open the motor electrical circuit at each extreme travel B - To open the motor electrical circuit when a predetermined torque has been developed by the motor C - To cause an increase in speed of response to a control signal D - Both a and b
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Question 6: The air used to operate a pneumatic valve actuator must be free of: A - Oil and nitrogen B - Water and oxygen C - Oil and water D - Water and carbon dioxide _______________________________________________
Question 7: The air supply system for pneumatic actuators that receive an air supply from a source separate from that supplying the controller is usually equipped with a __________ to collect condensed ________________. A - sump, moisture B - valve, solids C - sump, solids D - filter, moisture _______________________________________________
Question 8: A solenoid operated valve may be used to control the position of the disc in a globe valve when the: A - Spring in the actuator requires extra force to open the valve B - Valve plug must be modulated at intermediate positions C - Valve must be fully open or fully closed D - Response speed of the actuator must be increased _______________________________________________
Question 9: Solenoid valves are employed in small size systems where: A - On-off operation is required B - Modulating service is required in day-to-day operations C - The position of the valve must be precisely regulated D - A reversed actuator is used to control the valve _______________________________________________
Question 10: Chain and wheel operators are used for valves that: A - Cannot be operated by one person B - Cannot be located within easy reach C - Require automatic valve positioning using a remote operating device D - Require electro-hydraulic operators and a remote operating device _______________________________________________
Question 11: Equipping larger valves with a gear system is one solution to the ________________ required to operate the valve. A - low torque B - handwheel C - high torque D - additional manpower _______________________________________________
Question 12: Pneumatic or hydraulic piston actuators are used when: A - A much greater stem movement is required than a diaphragm actuator can provide B - The air used for control purposes is contaminated with moisture, oil or particles of dirt C - The force required to position a valve or a damper is less than that which can be provided by a diaphragm D - Both a and c _______________________________________________
Question 13: Air loaded diaphragm actuators are considered superior to spring loaded types in many applications because: A - The spring and the unbalanced force on the valve plug oppose the air pressure on the diaphragm B - Spring action can be erratic and the force provided by the spring is constant at any degree of compression C - Spring action is constant but the force provided by the spring is erratic at any degree of compression D - Differential control is achieved by a single air pressure signal _______________________________________________
Question 14: A pneumatic actuator converts an air signal into valve stem motion by: A - Operating the solenoid by air pressure B - Telemetry C - Applying pressure to a diaphragm D - All of the above _______________________________________________
Question 15: With an air loaded diaphragm actuator design: A - A spring and the unbalanced force on the valve plug, due to the process pressure, opposes the air pressure on the diaphragm B - Two air signal pressures control the valve differentially C - Differential control is achieved by a single air pressure signal D - Spring action is constant but the force provided by the spring is erratic at any degree of compression _______________________________________________
Question 16: Pneumatic actuators are: A - Never used for on-off operation B - Only used for on-off operation C - Rarely used for modulating service D - Typically used for modulating service _______________________________________________
Question 17: Pneumatic actuators are widely used in the petroleum and chemical industries because: A - Instrument air is readily available B - They are less expensive than other actuators C - They are safe, simple and reliable D - They are most popular for on-off operation _______________________________________________
Question 18: Pneumatic actuators are typically used for modulating service and are never used for on-off operation. A - True B - False _______________________________________________
Question 19: In a small, low-pressure application where throttling service is not required of valves, the most appropriate and cost-effective valve actuator would be a/an:
A - Solenoid B - Chain and wheel C - Electric motor D - Geared hand-crank _______________________________________________
Question 20: The main disadvantage of an electric valve operator is:
A - The valves must be installed at the appropriate operating levels B - They cannot be operated from several locations C - They are relatively expensive, in both equipment and wiring costs D - That only a small range of valve operating speeds can be obtained
BLRS 6021_Pressure Safety Devices
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Question 1: A spring-loaded device that acts as a safety valve in gas service and as a relief valve in liquid service is called a: A - Pilot-operated pressure-relief valve B - Water sealed safety-relief device C - Relief valve D - Safety-relief valve _______________________________________________
Question 2: A pilot-operated pressure relief valve is a valve in which the major relieving device is combined with, and is controlled by a:
A - Self-actuated gate valve B - Water sealed safety-relief valve C - Manually operated pressure-relief valve D - Self-actuated pressure-relief valve _______________________________________________
Question 3: The type of safety valve shown in the illustration seen here is a:
A - Conventional safety-relief valve B - Power-actuated pressure-relief valve C - Pilot-operated pressure-relief valve D - Water sealed safety-relief valve _______________________________________________
Question 4: Power-actuated relief valves can be used instead of code-required safety valves as they do essentially the same job. A - True B - False _______________________________________________
Question 5: The pressure safety device in which the major relieving device is combined with, and is controlled by a self-actuated pressure-relief valve is the:
A - Pilot-operated pressure-relief valve B - Water sealed safety-relief device C - Safety-relief valve D - Power-actuated pressure-relief valve _______________________________________________
Question 6: A relief valve is a spring-loaded device that begins to open when the inlet pressure reaches set pressure, overcomes the spring force, and begins to lift the disk off the seat. It is used in: A - Gas service B - Liquid service C - Steam service D - All of the above _______________________________________________
Question 7: In a pilot-operated safety-relief valve, pressure is exerted on both sides of the main valve. The valve is held closed because the dome surface area is: A - Larger than the system side B - Smaller than the system side C - The same size as the system side D - None of the above
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Question 8: Inadvertent contact between the lifting cam and the spindle nut of a pressure relief valve may be the result of: A - Vibration and pulsing pressure B - Incorrectly adjusting lifting gear C - Damaged springs D - Rough handling _______________________________________________
Question 9: Pilot-operated safety-relief valves are primarily used: A - In general refinery process service B - Where chemical compatibility of the process fluid with the diaphragms is questionable C - Where there is low differential between normal operating pressures and set pressure of the valve D - In viscous liquid service _______________________________________________
Question 10: The operational characteristics of a conventional safety-relief valve are directly affected by changes in the: A - Process flow B - Valve outlet pressure C - Backpressure on the valve D - Tension on the main spring _______________________________________________
Question 11: Pilot-operated safety-valves are not used: A - In viscous liquid service B - Where large relief areas at high set pressure are required C - On large, low-pressure storage tanks D - Where very short blowdown is required _______________________________________________
Question 12: A pressure gauge, a try cock, a free vent, or a suitable indicator should be inserted _____________ a rupture disk device installed at the ___________ of a pressure-relief valve and the valve itself to detect disk rupture or leakage.
A - beside; outlet B - between; inlet C - between; outlet D - beside; inlet _______________________________________________
Question 13: Damaged flanges and misaligned valve parts of a pressure-relief valve can result from:
A - Vibration and pulsating pressure B - Leakage C - Rough handling D - Incorrect calibration _______________________________________________
Question 14: Which pressure relief valve problem could cause the disk to rub against the seat, resulting in leakage? A - Incorrect calibration B - Vibrating and pulsating pressure C - An incorrectly adjusted lifting gear D - Damaged springs _______________________________________________
Question 15: If you were designing a system where any superimposed backpressure is constant and any built-up backpressure will not exceed 10% of the set pressure, the type of safety pressure device that you would include in your design should be a: A - Conventional safety-relief valve B - Water-sealed safety-relief valve C - Rupture disk D - Power-actuated pressure-relief valve _______________________________________________
Question 16: The safety-relief device that is referred to as a non-reclosing pressure relief device is a: A - Pilot-operated pressure-relief valve B - Relief valve C - Water sealed safety-relief device D - Rupture disk _______________________________________________
Question 17: Rupture disks are used to protect:
A - The upstream side of pressure valves against corrosion by the system fluid B - The downstream side of pressure relief valves against atmospheric corrosion C - Pressure relief valves against plugging or clogging by viscous fluids D - All of the above _______________________________________________
Question 18: The safety valve has a valve disk that is held firmly on its seat by: A - A carbon-steel casing welded directly to the pipe B - Two adjustable nuts that are equipped with locknuts C - The pressure of the process flow D - The pressure of a heavy coil spring _______________________________________________
Question 19: When maximum pressure is reached, the metal membrane of a rupture disk fails and: A - Blows apart in fragments B - Dissolves C - Gradually relieves the pressure D - Peels open _______________________________________________
Question 20: The force of the pressure acting on the safety valve disk is a function of: A - Seat diameter B - Spring tension C - Disk area D - Percentage of valve opening
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
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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
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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
