Gas - Valves and Regulators Flashcards
What do the lubricated gas shut-off valve and spring loaded gas shut-off valve have in common?
Both open and close with a quarter of a turn.
Servo-operated and redundant gas valves are both types of _________ gas valves.
Combination.
In a servo-operated valve, the force that opens the main valve is caused by:
A. A solenoid.
B. Gas pressure from a regulator.
C. The inlet gas pressure of the valve.
D. A spring[][][][][][][][][][][][][][][][][][][][][][][][][]
B. Gas pressure from a regulator.
In a redundant gas valve, the force that opens the main valve is caused by:
A. A solenoid.
B. Gas pressure from the regulator.
C. The inlet gas pressure of the valve.
D. A Spring[][][][][][][][][][][][][][][][][][][][][][][][][]
C. The inlet gas pressure of the valve.
If the main gas valve of a redundant gas valve failed open with debris when the call for heat is satisfied, the main flame would:
A. Go out.
B. Keep burning until the flame safeguard lost the pilot flame.
C. Keep burning indefinitely[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
A. Go out.
True or False?
Rod-and-tube type gas control valves are primarily used on service water heaters.
True.
True or False?
The invar rod expands more than the copper tube.
False.
True or False?
Hydraulically-operated valves use an expanding liquid inside a sensing bulb, capillary tube, and bellows.
True.
True or False?
Snap or clicker mechanisms are used to provide two positions of the valve, full open and completely closed.
True.
True or False?
ECO stands for energy cut-off.
True.
True or False?
A seismic valve once activated must be manually reset.
True.
True or False?
A cable release valve is always activated manually.
False.
Referring to the figure below, the letter “A” indicates which of the following?
A. Appliance shut-off valve.
B. “B” Cock[][][][][][][][][][][][][][]]
C. “B” Cock[][][][][][][][][][][][][][]]
D. Branch isolation valve[][]]
A. Appliance shut-off valve.
Referring to the figure below, the letter “C” indicates which of the following?
A. Appliance shut-off valve.
B. “A” Cock[][][][][][][][][][][][][][][]
C. “B” Cock[][][][][][][][][][][][][][]]
D. Branch isolation valve[][][]
C. “A” Cock.
Referring to the figure below, the letter “D” indicates which of the following?
A. Appliance shut-off valve.
B. “A” Cock[][][][][][][][][][][][][][][]
C. “B” Cock[][][][][][][][][][][][][][]]
D. Branch isolation valve[][]]
C. “B” Cock.
Referring to the figure below, the letter “B” indicates which of the following?
A. Appliance shut-off valve.
B. Pilot valve[][][][][][][][][][][][][]]
C. Safety shut-off valve[][][][]]
D. Branch isolation valve[][]]
C. Safety shut-off valve.
Referring to the figure below, the letter “E” indicates which of the following?
A. Appliance shut-off valve.
B. Appliance regulator[][][][][]
C. Automatic gas valve[][][][]]
D. Safety shut-off valve[][][][]]
B. Appliance regulator.
Referring to the figure below, when the reset button is depressed:
A. Only pilot gas can pass through the valve.
B. Only main gas can pass through the valve.
C. The igniter is energized and the main burner can light.
D. All the gas flow is interrupted until the thermocouple reaches temperature.
A. Only pilot gas can pass through the valve.
Referring to the figure below, a weak magnet will cause the valve to:
A. Fail in the open position.
B. Shut off the power to the thermocouple.
C. Close the reset button to block gas flow[]
D. Shut off all gas flow[][][][][][][][][][][][][][][][][][][][]
D. Shut off all gas flow.
Referring to the figure below, this valve can be mounted:
A. In any vertical or horizontal position.
B. Only in the horizontal upright position.
C. In any vertical position[][][][][][][][][][][][][][][]
D. In a horizontal position with a rotation of up to 90°
B. Only in the horizontal upright position.
Referring to the figure below, installing the valve backwards in the gas line could result in:
A. Gas leaking through the valve when it is not energized.
B. No gas flow when the valve is energized[][][][][][][][][][][][][]]
C. Gas pressure holding the valve closed and it will never open.
D. Continuous uninterrupted gas flow at all times[][][][][][][][][][][][][][]]
A. Gas leaking through the valve when it is not energized.
Referring to the figure below, this valve is known as:
A. Diaphram gas valve.
B. Servo gas valve[][][][]]
C. Redundant gas valve.
D. Solenoid valve[][][][][]]
D. Solenoid valve.
Referring to the figure below, this valve is known as:
A. Diaphram gas valve.
B. Servo gas valve[][][][]
C. Redundant gas valve.
D. Solenoid valve[][][][][][]
A. Diaphram gas valve.
Referring to the figure below, if the pressure port is plugged on installation of the valve:
A. The valve will never fully open.
B. The valve will never tightly close.
C. The valve will not accurately control manifold pressure.
D. The valve will respond very slowly to a call for heat[][][][]
B. The valve will never tightly close.
Referring to the figure below, if the vent line becomes completely plugged with carbon:
A. The valve will never open.
B. The valve will never close.
C. The valve will not accurately control manifold pressure.
D. The valve will respond very slowly to a call for heat[][][][]
A. The valve will never open.
Referring to the figure below, only during a call for heat (burner operating) it is noticed that there is a flare on the vent line. This could be due to:
A. Dirt under the main diaphram.
B. Pin holes in the main diaphram.
C. The armature has broken off[][][]
D. The armature spring has broken.
B. Pin holes in the main diaphram.
Referring to the figure below, only during the off cycle of the burner it is noticed that there is a flare on the vent line in the combustion chamber. This could be due to:
A. Dirt under the diaphram.
B. The armature spring has broken.
C. The armature has broken[][][][][][]]
D. Pin holes in the main diaphram[]]
B. The armature spring has broken.
Referring to the figure below, the letter “A” indicates the:
A. Safety shut-off valve magnet.
B. Main appliance shut-off valve.
C. “A” cock[][][][][][][][][][][][][][][][][][][][]]
D. Combination “A” cock and “B” cock.
C. “A” cock.
Referring to the figure below, the letter “B” indicates the:
A. Safety shut-off valve magnet.
B. Main appliance shut-off valve.
C. “A” cock[][][][][][][][][][][][][][][][][][][][]]
D. Appliance regulator[][][][][][][][][]
D. Appliance regulator.
Referring to the figure below, the letter “C” indicates the:
A. Safety shut-off valve magnet.
B. Main automatic valve actuator.
C. “A” cock[][][][][][][][][][][][][][][][][][][][][]
D. Combination “A” cock and “B” cock.
B. Main automatic valve actuator.
Referring to the figure below, the letter “D” indicates the:
A. Safety shut-off valve magnet.
B. Main appliance shut-off valve.
C. “A” cock[][][][][][][][][][][][][][][][][][][][][]]
D. Combination “A” and “B” cock[]
A. Safety shut-off valve magnet.
Referring to the figure below, this valve is know as:
A. Diaphram gas valve.
B. Servo gas valve[][][][]
C. Solenoid valve[][][][][]
D. Redundant gas valve.
B. Servo gas valve.
Referring to the figure below, what condition would result if the valve was installed backwards?
A. The valve would provide poor control of the pilot gas.
B. The valve would open when it was not energized[][][][]
C. The valve will not open to allow a flow of gas[][][][][][][][]
D. The main valve will not open and not close[][][][][][][][][][]
B. The valve would open when it was not energized.
Referring to the figure below, if the servo regulator diaphram ruptured, the most likely result would be:
A. When energized it will not regulate gas flow.
B. The valve will close and never open[][][][][][][][]
C. The valve will not energize[][][][][][][][][][][][][][][][]]
D. The valve will fail wide open[][][][][][][][][][][][][][][]
A. When energized it will not regulate gas flow.
Referring to the figure below, this valve is commonly known as:
A. Diaphram gas valve.
B. Solenoid valve[][][][][]
C. Servo valve[][][][][][][][]
D. Redundant valve[][][]]
D. Redundant valve.
Referring to the figure below, this valve regulates the pressure to:
A. Both pilot and main burner.
B. Main burner only[][][][][][][][][]]
C. Pilot only[][][][][][][][][][][][][][][][][]
D. Neither main burner nor pilot.
A. Both pilot and main burner.
Referring to the figure below, the first action on a call for heat is:
A. Gas flows to the pilot burner.
B. Pilot valve opens[][][][][][][][][][][]
C. Pilot operator is energized[][]]
D. Both main and pilot valve energize together.
C. Pilot operator is energized.
Referring to the figure below, the valve operation is caused by the:
A. Spring tension.
B. Expansion of the invar rod.
C. Expansion of the copper tube.
D. Inlet pressure of the gas[][][][][]]
C. Expansion of the copper tube.
Referring to the figure below, extreme corrosion of the copper tube may cause:
A. The valve to stay wide open.
B. The valve to remain closed[][]
C. Water to enter into the gas line.
D. Gas to enter into the hot water tank.
B. The valve to remain closed.
Referring to the figure below, a rupture of the bellows will cause:
A. Water to enter the gas line.
B. Gas to enter the hot water tank.
C. The valve to fully close[][][][][][][][]
D. The valve to fully open[][][][][][][][]
D. The valve to fully open.
Which regulator is used at a gas meter to reduce service pressure?
Service regulator.
Which regulator is used downstream of a service regulator but upstream of an appliance regulator?
System regulator.
Which regulator is used at the appliance?
Appliance regulator.
Which element of a regulator is usually a spring?
Loading element.
Which element of a regulator is usually a diaphram?
Measuring element.
Which element of a regulator is usually a valve, disk or plug?
Restricting element.
True or False?
Regulators respond to a change in downstream flow without any change in downstream pressure.
False.
The desired downstream pressure is the definition of?
Setpoint.
The pressure above setpoint that is needed to shut off tight is the definition of?
Lockup.
The downstream pressure drop below setpoint is the definition of?
Droop.
True or False?
With a larger orifice in the regulator a specific change in downstream pressure produces a smaller change in flow rate than it would with a smaller orifice.
False.
More gas going through.
The “open and close repeatedly” effect that too large an orifice would have in a regulator is the definition of?
Cycling.
The “disc is slammed into the orifice” effect that too large an orifice would have in a regulator is the definition of?
Bathtub stopper effect.
What are two effects that too large an orifice would have in a regulator?
Higher lockup pressure.
Faster wear on the valve disc and orifice (not much distance).
When sizing a regulator there are choices to be made. From the list below identify the best choices.
A. Select the largest orifice.
B. Select the smallest diaphram.
C. Select the heaviest spring rate.
D. Select the lightest spring rate[]]
E. Select the largest diaphram[][][]]
F. Select the smallest orifice[][][][][]
D. Select the lightest spring rate[][]
E. Select the largest diaphram[][][]]
F. Select the smallest orifice[][][][][]
List two features that would improve the perfomance and accuracy of a regulator.
Pitot tube (tricks regulator).
Pressureless lever (stronger lockup force / less tendency of disc cycling).
Are single-stage regulator systems allowed on propane installations?
No.
List four advantages that a two-stage propane pressure regulatory system has over a single-stage system.
- Uniform appliance pressure[][][][][][][][][][][][][][][][]
- Reduce freeze-ups and service calls[][][][][][][][]
- Economy of installation[][][][][][][][][][][][][][][][][][][][]
- Allowance for future appliances is enhanced.
List two options for a two-stage pressure regulation system.
- A first-stage high pressure regulator.
- An integral twin-stage regulator[][][][]
List six considerations when selecting a gas pressure regulator.
Inlet pressure.
Outlet pressure.
Overpressure protection.
Pipe size[][][][][][][][][][][][][][][]
Rate of flow[][][][][][][][][][][][]]
Type of gas[][][][][][][][][][][][][]
Describe three considerations to bear in mind when installing a gas pressure regulator.
Enough room for servicing.
Outlet length 18” before any pipe size changes.
Shut off valve upstream and main gas line and vent line connection must have a union to disassemble.
Referring to the figure below, what type of regulator is pictured and what makes it this type of regulator?
Direct operated (poppet style).
There’s no positive lockup (simplistic regulator).
Referring to the figure below, what is component “A” and what is it’s function?
Loading element (spring).
Adjusts the setpoint[][][][][]
Referring to the figure below, what is component “B” and what is it’s function?
Measuring element (sensing element).
Measures the changes in the downstream flow.
Measures or senses downstream gas pressure.
Referring to the figure below, what is component “C” and what is it’s function?
Restricting element (valve disk and seat).
Controls the amount of flow by leaving the orifice full open, closed or in between.
Referring to the figure below, what is component “D” and what is it’s function?
Atmospheric vent.
Allows the air above the diaphram to escape or enter as the diaphram goes up/down
Referring to the figure below, how would you adjust component “A” in order to get a higher downstream pressure?
By varying the compression of the adjusting spring (tighten clockwise).
Referring to the figure below, what would happen if component “D” was blocked upon installation? What about if it was blocked after installation but while there was a call for heat?
It won’t work properly.
It will regulate improperly.
The force of downstream pressure across the bottom of the diaphram equals the force of the weight or spring pressure bearing down on the top surface of the diaphram is the definition of?
When a regulator is in equilibrium.
The spring (loading element) of the regulator determines the desired downstream pressure under various flow conditions is the definition of?
Setpoint.
Can you change the setpoint and if so how would you do that?
Yes you can change the setpoint.
By adjusting the amount of compression on the loading spring.
What is the maximum pressure that you can run into a one or two family dwelling?
2 psi.
Can you bypass a regulator?
No.
Referring to the figure below, what type of regulator is pictured?
Propane two-stage integral.
When ordering a regulator what are the three main characteristics of the regulator which you need to take into consideration?
Flow rate.
Inlet pressure.
Outlet pressure.
(Size of pipe)[][][]
Referring to the figure below, this is commonly referred to as:
A. Service regulator
B. Line pressure regulator
C. Appliance regulator[][][][]
D. Pilot-operated regulator
C. Appliance regulator.
Referring to the figure below, letter “A” is referring to the:
A. Restricting element.
B. Measuring element.
C. Loading element[][][]
D. Vent opening[][][][][][]
D. Vent opening.
Referring to the figure below, letter “B” is referring to the:
A. Restricting element.
B. Measuring element.
C. Loading element[][][]
D. Vent opening[][][][][][]
C. Loading element.
Referring to the figure below, letter “C” is referring to the:
A. Restricting element.
B. Measuring element.
C. Loading element[][][]
D. Vent opening[][][][][][]
B. Measuring element.
Referring to the figure below, letter “D” is referring to the:
A. Restricting element.
B. Measuring element.
C. Loading element[][][]
D. Vent opening[][][][][][]
A. Restricting element.
Referring to the figure below, if component “A” was plugged on installation of the regulator, the probable result will be:
A. The regulator will not open.
B. The regulator will not close.
C. The regulator will respond slowly to changes in downstream pressure.
D. Unusually high downstream pressures[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
C. The regulator will respond slowly to changes in downstream pressure.
D. Unusually high downstream pressures[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
Referring to the figure below, if component “B” breaks, the probable result will be:
A. The will not fully open.
B. The regulator will not fully close.
C. The regulator will respond slowly to changes in downstream pressure.
D. Unusually slow downstream pressure and flow rates[][][][][][][][][][][][][][][][]]
D. Unusually slow downstream pressure and flow rates.
Referring to the figure below, if component “C” should rupture, the probable result will be:
A. The regulator will go fully open[]]
B. The regulator will go fully closed.
C. The regulator will hunt[][][][][][][][][][]]
D. Unusually low downstream pressure.
A. The regulator will go fully open.
Referring to the figure below, if the regulator is installed backward, the probable result will be:
A. The regulator will not open.
B. The regulator will not close.
C. The regulator will respond slowly to changes in downstream pressure.
D. Unusually high downstream pressure[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
A. The regulator will not open.
Referring to the figure below, “C” is pointing to the small spring. This is known as the:
A. Measuring spring.
B. Main loading spring.
C. Relief valve loading spring.
D. Pilot valve spring[][][][][][][][][]]
C. Relief valve loading spring.
Referring to the figure below, the main reason the regulator is able to provide positive shut-off is because of:
A. High inlet pressure.
B. High outlet pressure.
C. Mechanical advantage.
D. The metal disk advantage.
C. Mechanical advantage.
Referring to the figure below, dirt lodged between the disk and seat will most likely cause:
A. Excessively high downstream pressures during high flow rates
B. The regulator to discharge during low flow rates[][][][][][][][][][][][][]
C. The relief valve to discharge during periods of high flow rates
D. The regulator to lock up[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]]
B. The regulator to discharge during low flow rates.
Referring to the figure below, an undersized vent line on a regulator may cause the:
A. Regulator to go into a hunting condition.
B. Restricting element to fully open[][][][][][][]]
C. Restricting element to stay fully open[][][]
D. Pilot safety to fail[][][][][][][][][][][][][][][][][][][][][]]
A. Regulator to go into a hunting condition.
Referring to the figure below, if the relief vent is terminated above the roof in such a way that rain water may enter the vent and lay on top of the diaphram, the likely result would be:
A. Regulator restricting element will fully open and not provide regulation.
B. Regulator restriciting element will fully close and not provide good regulation.
C. Loading element will fully collapse[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
D. Downstream pressure will be reduced to the point of burner flashback[][][][][][][]
B. Regulator restriciting element will fully close and not provide good regulation.
If the orifice in the restricting element of a pressure regulator is too small, the:
A. Pressure on the downstream side of the regulator will become too high.
B. Regulator will hunt[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]
C. Regulator will open and close rapidly causing damage to the disc[][][][][][][]
D. Restricting element will fully open and not be able to maintain the required downstream pressure.
D. Restricting element will fully open and not be able to maintain the required downstream pressure.
When selecting the components of a service regulator, the required downstream pressure will be determined by the selection of the:
A. Proper body size.
B. Loading element[]
C. Measuring element.
D. Restricting element.
B. Loading element.
An appliance regulator is allowing gas pressure to fluctuate above and below it’s setpoint. This can be caused by:
A. A completely plugged pilot tube.
B. A pinhole in the diaphram[][][][][][]]
C. Too large of a vent opening[][][][][][]
D. A partially plugged vent opening[]
D. A partially plugged vent opening.
All appliance regulators will require a vent to allow:
A. The diaphram to move up and down freely[]
B. Gas to escape when the diaphram ruptures.
C. Gas to escape if the relief valve opens[][][][][]
D. The gasfitter to check downstream pressure.
A. The diaphram to move up and down freely.
The K factor of a gas regulator loading spring is the:
A. Spring rate.
B. Coefficient of expansion.
C. Lockup range[][][][][][][][][][][]
D. Percentage of Kanthol in the spring.
A. Spring rate.
The area inside a regulator known as the vena contracta is an area of:
A. Lower than downstream pressure.
B. Higher than downstream pressure.
C. Slow gas pressure[][][][][][][][][][][][][][][]]
D. Minimal droop[][][][][][][][][][][][][][][][][][][]]
A. Lower than downstream pressure.
In the discussion of regulator performance, boost is a term that describes:
A. Critical flow.
B. Stopper affect.
C. The pressure at the vena contracta.
D. Pressure above setpoint[][][][][][][][][][][]
D. Pressure above setpoint.
A solenoid gas valve installed upside down may:
A. Remain closed when the valve is energized.
B. Stick closed when the valve is energized[][][]
C. Open very quickly when energized and cause a noisy light-off on the main burner.
D. Remain open and never close[][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][][]]
D. Remain open and never close.
These valves are designed to shut the gas off during an earthquake.
A. Check valve.
B. Combination valve.
C. Plug valve[][][][][][][][][]
D. Seismic valve[][][][][][]
D. Seismic valve.
These valves are designed to shut off the gas to equipment if there is a fire.
A. Cable release valves.
B. Check valves[][][][][][][]]
C. Plug valves[][][][][][][][][]]
D. Seismic valves[][][][][][]]
A. Cable release valves.
These two manual valves are the most common manual shut off valves in the gas industry.
A. Ball & Plug.
B. Globe & Check.
C. Gate & Check[][]
D. Solenoid & Control.
A. Ball & Plug.
Regulators, when they are installed, are in the ___________ position.
A. Downstream.
B. Normally closed.
C. Normally open[][]
D. Vertical[][][][][][][][]
C. Normally open.
Regulators operate on a change in _________________.
A. Atmoshperic pressure.
B. Downstream pressure.
C. Lock up pressure[][][][][]
D. Upstream pressure[][][]
B. Downstream pressure.
Once the restricting element is fully open and the capacity drops off sharply. This is referred to as:
A. Critical flow.
B. Droop[][][][][]]
C. Lock up[][][][]
D. Set point[][][]
A. Critical flow.
These are added to the regulator to make them more effective.
A. Larger inlets and outlets.
B. Lubricated parts[][][][][][][][]
C. Levers and pitot tubes[][]]
D. Levers and vents[][][][][][][]
C. Levers and pitot tubes.
By using a _______ the regulator is tricked into responding with a greater response to changes in pressure.
A. Lever.
B. Pitot tube.
C. Thicker diamphram.
D. Universal disk[][][][][]]
B. Pitot tube.
Vent pipes on automatic valves, diaphram gas valves, pressure regulators etc. shall not have an inside diameter of less than:
A. 1/4”.
B. 3/8”.
C. 1/2”[]
D. 5/8”.
A. 1/4”.
Positive shut-off is required on all line pressure regulators when the system pressure exceeds:
A. 1/2 psig.
B. 2 psig[][]
C. 5 psig[][]
D. 20 psig[]
A. 1/2 psig.
A Natural Gas pressure regulator equipped with a leak limiter will restrict the escape of gas to approximately:
A. 2.5ft³/hr.
B. 2ft³/hr[][]]
C. 2% of the regulator’s capacity.
D. 3 1/2% of the regulators capacity.
A. 2.5ft³/hr.
Solenoid gas valves with manual opening devices are:
A. Highly recommended for all gas installations.
B. Not allowed on any gas installation[][][][][][][][][]
C. Restricted to Propane-fired gas installations[]]
D. Rapidly replacing solenoid gas valves that are not equipped with manual opening devices.
B. Not allowed on any gas installation.
When two or more gas over-pressure relief devices are installed, they may be connected into a single vent line, provided that the single vent line has an area equal to the largest relief device opening plus ___ of the total area of the other relief devices.
A. 10%.
B. 25%.
C. 50%.
D. 75%.
C. 50%.
