Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Gas lvl 4 > Gas valves > Flashcards

Gas valves Flashcards

1
Q

how does a solenoid valve operate?

A

The most rudimentary of automatic gas valves is the solenoid valve. A controller (e.g.,
thermostat, aquastat, etc.) closes and completes a circuit which energizes a magnetic
coil pulling an armature (valve stem) and valve disk off of a valve seat. This allows gas
to flow to the burner. When the controller is satisfied it opens the circuit and deenergizes the electro-magnet (coil) causing the valve disk to fall back onto the seat from
its own weight and the upstream gas pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what orientation must a solenoid be installed in? what is the power source (voltage)

A

must be installed upright, operates on 120 or 24 v

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

does a diaphragm gas valve regulate gas flow?

A

no, it only functions as a on and off for gas delivery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what does a combination gas valve do?

A

combines all of the components of a gas valve train into one valve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

whats the main difference in operation between a diaphragm valve and a combo valve?

A

a sensing regulator?

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what does a sensing regulator do?

A

allows the valve to automatically adjust gas flow and pressure to a preset level. preset level is adjusted by adjusting spring tension in the regulator. (only on the main burner)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

on a combo valve, is the inlet pressure different or the same as the pilot. what pressures?

A

they are the same. 4.5-10” WC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what psi will a one stage redudant gas valve deliever fuel at?

A

3-4 inches wc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

what psi will a two stage redudant gas valve deliver fuel at?

A

first, 1 - 1.5 inches wc and then 3-4 inches wc on high fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

what type of pilot does a single stage redudant gas valve operate with?

A

intermitent pilot

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

how does a rod and tube gas valve operate

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is an eco and how does it operate?

A

Energy cut off. operates by breaking a circuit between the thermocouple and the safety valve when the water exceeds 200 f

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

where are hydraulic gas valves often found?

A

mobile homes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

how does a nova gas valve energize the safety shut of valve and main burner?

A

thermocouple and thermopile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

at what % of air will an oxidation depletion sensor shut the gas supply off

A

18%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what are the 3 configurations of a nova gas valve?

A

split pilot flame for fast ffrt, an o.d.s system,

17
Q

where must a gas valve be located in a fire suprresion system?

A

outside of the fire supression area

18
Q

does an earthquake valve automatically reset or does it have to be manually reset?

A

manually

19
Q

what opens and closes a diaphgram valve?

A

upstream gas pressure

20
Q

what powers a diaphgram valve

A

120 volts, 24 or milivoltage

Gas lvl 4 (3 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions