Assemblies

Question 1

Which assembly has only one test cock?

Answer 1

SVB

Question 2

Which assembly has four shut offs, four checks & 8 test cocks?

Answer 2

DCDA

Question 3

Maximum allowable pressure loss across a Double check assembly?

Answer 3

10 PSIG

Question 4

It is recommended that a DC be installed with its critical level a minimum of ____ inches above the floor?

Answer 4

12inches

Question 5

What is the minimum pressure drop across each check of a DC in a static condition?

Answer 5

1.0 PSID

Question 6

Where is the #2 test cock of a DC located?

Answer 6

upstream of check valve #1

Question 7

What is considered to be critical level of a PVB if it is not marked?

Answer 7

The bottom of the valve body

Question 8

What can be done if the air inlet valve of a PVB will not seat?

Answer 8

Increase the supply pressure

Question 9

What is the reason for the meter on a DCDA ?

Answer 9

To detect unauthorized water usage

Question 10

A DC may be used for what type of hazard only?

Answer 10

Low

Question 11

The purpose of the bypass flow indicator is to detect low flow rates up to how many GPM ?

Answer 11

2GPM

Question 12

The PVB shut-off valves are located where on the assembly?

Answer 12

At the inlet and outlet of the assembly

Question 13

A DC consists of how many valves & checks?

Answer 13

2 of each

Question 14

Are the checks of a DC interchangeable?

Answer 14

YES

Question 15

Where is the #1 test cock located on a PVB?

Answer 15

Upstream of the check

Question 16

Can the PVB & SVB be subjected to continuous pressure?

Answer 16

YES

Question 17

What is the critical level of a PVB or SVB?

Answer 17

12 inches above the highest downstream use.

Question 18

How many test cocks does a PVB have on the assembly?

Answer 18

2 test cocks

Question 19

How many test cocks does an SVB have on the assembly?

Answer 19

One test cock

Question 20

An SVB ‘s check must be drip-tight at ?

Answer 20

1.0 PSID

Question 21

The opening PSID of an SVB air inlet valve is a minimum of ?

Answer 21

1.0 PSID

Question 22

What is the maximum allowable pressure drop across a PVB or SVB?

Answer 22

10 PSIG

Question 23

What is the maximum protection provide by the PVB or SVB?

Answer 23

High hazard - backsiphonage

Question 24

A characteristic of the SVB operation is that the air inlet must seal before the :

Answer 24

Check opens

Question 25

Can the PVB or SVB have valves downstream of the assembly?

Answer 25

YES

Question 26

Could a PVB or SVB be subjected to backpressure and where would the backpressure come from?

Answer 26

YES and a closed downstream valve

Question 27

The hydraulic purpose of any vacuum breaker is to stop:

Answer 27

a siphon

Question 28

What is the minimum check valve closing differential for a PVB?

Answer 28

1.0 PSID

Question 29

The springs on the 2 check valves of an RP are

Answer 29

Always loaded differently

Question 30

Why should the #2 shut-off valve be closed first when testing a DC,RP,PVB or SVB?

Answer 30

To maintain pressure in the assembly

Question 31

An enclosure around the installation of an RP must have:

Answer 31

a provision for drainage

Question 32

What cause occasional discharge of water from the relief opening on an RP?

Answer 32

A fluctuation in supply pressure

Question 33

Performance design specs of an RP requires the differential pressure across the #1 check to be at least ___PSI greater than the PSI of the relief valve.

Answer 33

3PSI

Question 34

What is the function of the spring in the relief valve of an RP ?

Answer 34

To force the relief valve open

Question 35

What is the critical level for an RP ?

Answer 35

12 inches

Question 36

The relief valve on an RP remains closed during normal operation due to:

Answer 36

Supply side pressure

Question 37

What is the purpose for flushing the test cocks on all the assemblies?

Answer 37

To remove any trash that may be in the test cock

Question 38

How can you stop an occasional discharge of water from the relief valve of an RP caused by supply pressure fluctuations?

Answer 38

Install a soft seated check valve upstream of the assembly

Question 39

Can an RP be installed in the vertical position?

Answer 39

Yes , if it has been tested and approved for that installation.

Question 40

What is the minimum differential pressure drop across the #1 check valve of an RP?

Answer 40

5 PSID

Question 41

What is the maximum protection offered by an RP ?

Answer 41

High hazard - backpressure & backsiphonage

Question 42

What is the minimum differential pressure drop across the #2 check valve of an RP?

Answer 42

1.0 PSID

Question 43

Where should an RP never be installed?

Answer 43

In a pit or a vault

Question 44

What is the minimum loading to open the relief valve of an RP?

Answer 44

2PSID

Question 45

The calculated value between the #1 check valve and the relief opening is referred to as the :

Answer 45

Buffer

Question 46

Where should a strainer be installed on an RP or DC?

Answer 46

upstream of the assembly

Question 47

Where is the #1 test cock located on an RP or DC?

Answer 47

upstream of the #1 shut-off valve

Question 48

Where is the relief opening located in the RP?

Answer 48

Between the #1 & #2 checks

Question 49

For an assembly to be approved it must be?

Answer 49

in-line testable and repairable

Question 50

Why would an RP or DC be installed in parallel?

Answer 50

when it is vital to maintain continuous water flow