Chapters 4-5

Question 1

Three main operating elements of gas pressure regulator

Answer 1

1. Loading element
2. Measuring element
3. Restricting element

Question 2

What is an appliance regulator ?

Answer 2

The last regulator in the system before gas gets burned.

Sets burner manifold pressure

Has a low capacity, high capacity design
(High capacity straight through design)

Question 3

What is a surge arrester ?

Answer 3

Found on slow opening combination valves

Slows opening of the regulator but allows it to close normally

Question 4

What is a vent limiting orifice ?

Answer 4

Limits venting of gas if diaphragm is ruptured.

Limits flow rate to 1ft3/gas venting

Will limit opening closing speed equally

Question 5

Explain automatic safety vent limiting orifice

Answer 5

When the ball valve is closed any gas will be forced to escape through

designed to allow almost no restriction to the vent opening of the regulator

Question 6

Where is a service regulator located and what does it do ?

Answer 6

Located at the inlet of the gas meter

Reduces service line pressure to house pressure

Question 7

What is an internal safety release ?

Answer 7

Special seats located at the diaphragm and linkage connection.

Seat will open allowing gas to pass out through the vent if downstream pressure gets too high

Question 8

What is a lock off mechanism ?

Answer 8

equipped with an additional seat design to close, shutting off gas flow through the regulator if outlet pressure is too high.

Must be manually reset

Question 9

What is a positive shit off in service regulators ?

Answer 9

Provide a positive shutoff when no flow is occurring in the line to appliances. Will lockup to within 10% of the original outlet pressure setting