Backflow / Cross Connection

Question 1

An approved assembly consisting of spring loaded check valves and air inlet valve installed between two resilient seated shutoff valves is:

Answer 1

PVB (pressure vacuum breaker)

Question 2

An assembly consisting of two spring loaded check valves separated by a differential pressure relief valve is:

Answer 2

A reduced pressure backflow assembly

Question 3

This backflow assembly consists of two internally loaded check valves (either spring or weight loaded)

Answer 3

DCVA

Question 4

This assembly consists of an air inlet valve and a spring loaded check valve

Answer 4

PVBA

Question 5

The relief valve of a RPBA maintains a differential pressure of at least

Answer 5

2 psig

Question 6

This backflow assembly may also detect water loss or theft on a low hazard service

Answer 6

DCDA (double check detector assembly)

Question 7

This backflow preventer must not be installed upstream of a shutoff valve

Answer 7

AVB

Question 8

The air inlet valve of a PVBA must open at or above ___ psig

Answer 8

1

Question 9

An RPBA installed more than ____ feet above the floor shall have a platform provided for servicing and testing.

Answer 9

5 ft (1500 mm)

Question 10

Backflow preventer on a water service to protect the purveyor water supply but not the building occupants, referred to as ____ isolation

Answer 10

Premise isolation

Question 11

The #1 check valve on a RPBA is spring loaded to the ____ position

Answer 11

Closed

Question 12

The zone of reduced pressure in a RPBA will not be closer than ____ of the ____ pressure

Answer 12

2 psid (13.8 kPa) of the inlet pressure

Question 13

The relief valve on a RPBA is held closed by

Answer 13

Supply line pressure

Question 14

The check valves of a DCVA must hold in the direction of flow against

Answer 14

1 psig, equivalent of 27.7” of water column

Question 15

Any backflow assembly installed in a piping system where debris is a problem should have a ____ installed upstream

Answer 15

Strainer

Question 16

The relief valve discharges when you close shutoff #2. What is likely the problem?

Answer 16

The #1 check valve is leaking

Question 17

The second test of the RPBA would be to check which of the following

Answer 17

The #2 check valve

Question 18

If the #2 shut off valve of a RPBA does not close right, the assembly may still be tested with the help of a ____

Answer 18

Bypass hose

Question 19

A small drop in the differential pressure when opening the bypass valve, to test check valve #2 of an RPBA would indicate

Answer 19

Disc compression of #2 check valve

Question 20

When testing a DCVA with sight tubes, the tubes must be marked at ____ to obtain accurate test

Answer 20

28” (712 mm)

Question 21

When testing a DCVA with sight tubes, the tubes should be _____ long to obtain the correct test head pressure

Answer 21

36” (914 mm)

Question 22

The first test of the DCVA is

Answer 22

Check valve #1 in direction of flow

Question 23

During a test of a DCVA we notice that the sight tube connected to test cock #3 is dropping and water is discharging from test cock #4. This indicates

Answer 23

2 check valve is leaking

Question 24

Which shutoff valve is opened first when completing the test of a DCVA?

Answer 24

Shutoff #1

Question 25

The second test requirement, when testing a PVBA is the _____ holds tight in the direction of flow

Answer 25

Air inlet valve

Question 26

If when testing a RPBA the psid reading drops, it his would indicate that the pressure in the zone of reduced pressure is _____

Answer 26

Increasing

Question 27

The second test requirement of a RPBA is

Answer 27

2 check valve shall hold tight against all pressures in reverse direction

Question 28

Minimum buffer required for a RPBA?

Answer 28

3 psid

Question 29

To calculate the buffer of a RPBA ____ the relief valve opening psid from the ____

Answer 29

Subtract, actual psid

Question 30

What is the minimum number of test report forms required?

Answer 30

3

Question 31

When testing a RPBA with a 3-valve differential gauge, what is the cause of the relief valve failing to open when opening the LSCV to test the relief valve opening psid?

Answer 31

Shutoff #2 is leaking or not properly closed

Question 32

When testing a RPBA with a 3 valve differential gauge, what would cause the psid to rise when opening the BPCV while testing the #2 cv in reverse direction?

Answer 32

Leaking shutoff #2 and a backflow condition