Backflow Prevention And Cross Connection Control Frequently Tested Actual Exam Questions With Correct Answers

BACKFLOW PREVENTION AND CROSS CONNECTION
CONTROL FREQUENTLY TESTED ACTUAL EXAM
QUESTIONS WITH CORRECT ANSWERS
Question 1.
Relief valve discharges continuously. Problem May be caused by what 5 faults?

ANSWER
1. Faulty No. 1 check valve (F1CV)
2. Faulty No. 2 check valve with backpressure (F2CVwB)
3. Faulty relief valve (FRV)
4. Relief valve plugged sensing |ine(s) (RVPSL)
5. Relief Valve leaking diaphragm (RVLD)



Question 2.
Relief valve discharges intermittently. Problem May be caused by what 4 faults?

ANSWER
1. Properly working assembly with large pressure fluctuations
2. No.1 check valve reading is close to RV opening point, with small line
pressure fluctuation.
3. Water hammer
4. No. 1 check valve leak with intermittent flow through assembly.



Question 3.
During RP Test 1, Relief Valve discharges after No. 2 shutoff valve is closed. What does this
indicate?

ANSWER
1. Normally indicates faulty No. 1 check valve
• Dirty or damaged disc
• Dirty or damaged seat: or,
2. Leak through relief valve diaphragm



Question 4.
During RP Test 1, Relief valve would not open; differential on the field test kit would not drop.
What does this indicate?

ANSWER
1. Leaky No. 2 shutoff valve with flow through the assembly (L2SVwF)




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, Question 5.
During RP Test 1, Relief valve would not open, differential drops to zero. What does this
indicate?

ANSWER
1. Relief valve stuck closed due to corrosion or scale (RVSC).
2. Relief valve sensing line(s) plugged.



Question 6.
During RP Test 1, Relief valve opens too high (with sufficiently high No. does this indicate?

ANSWER
1. Faulty relief valve
• Dirty or damaged disc
• Dirty or damaged seat



Question 7.
During RP Test 1 or 3, Check Valve No. 1 check reading too low (less than 5.0). What does this
indicate?

ANSWER
1. Dirty or damaged disc
2. Dirty or damaged seat
3. Guide members hanging up
4. Damaged spring



Question 8.
During RP Test 2, Check Valve No. 2 is Leaking. What does this indicate?

ANSWER
1. Dirty or damaged CV 2 disc
2. Dirty or damaged CV 2 seat
3. CV2 guide members hanging up
NOTE: Lubricants should only be used to assist with the reassembly of components, and must be
non-toxic.



Question 9.
During DC Test for either check valve, the Check valve is reading below 1.0 psid. What does this
indicate?

ANSWER
1. Dirty or damaged check disc
2. Dirty or damaged check seat
3. Damaged spring




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