Backflow Test V Key Concepts And Practice Questions

BACKFLOW TEST V KEY CONCEPTS AND
PRACTICE QUESTIONS

◉ When a residential property has a backflow-prevention
device/assembly installed on the service line the best means to
control thermal expansion is with a.
Answer: Thermal expansion tank


◉ According to the Nebraska regulations what is the minimum
acceptable air gap for a 2" pipe located 1" from the wall.
Answer: 6"


◉ The RPBA must have a provision to drain away at least _____ times
the rated flow of the assembly.
Answer: 4


◉ When velocity of the water flowing in a service pipe increases, the
pressure available at the consumers tap _________.
Answer: Decreases


◉ The second check valve of a DCVA has become distorted. What
could have caused this?.
Answer: Water hammer

, ◉ The RPBA #1 check valve is ___________.
Answer: A heavier spring than used in the #2 check valve


◉ The check valve spring of a PVB ________.
Answer: Closes the check valve


◉ The _____ test cock of an RPBA is located on the inlet side of the
assembly.
Answer: #1


◉ If a 10" RPBA doesnt test properly.
Answer: Check to see if the downstream gate valve is leaking


◉ Back flow prevention testing equipment should be accuracy
verified at least every _______.
Answer: year


◉ A damaged or dirty disc or seat of an RPBA may account for ______.
Answer: A low first check differential