PVB , SVB & DC Flashcards
What is the critical level of a PVB?
12 inches above the downstream use
What can be done if the air inlet of a PVB will not seat?
Increase the supply pressure
Two areas were a PVB shouldn’t be installed?
In a pit or area with toxic fumes
How should a PVB be installed?
upright & plumb
A PVB is rated for what type of hazard and backflow?
High hazard & low hazard
Backsiphonge only
What is the maximum pressure drop across a PVB?
10 PSI
What is the minimum PSID for the check of a PVB?
1 PSID
What is the minimum PSID that the air inlet valve of a PVB must open out ?
1 PSID
How many test cocks are part of the PVB assembly?
Two Test Cocks
Where are the shut off valves located on a PVB assembly?
Inlet & Outlet
Can a PVB be subjected to continuous pressure?
Yes
The # 1 test cock of a PVB assembly is located where in relationship to the #1 shutoff?
Downstream
The hydraulic purpose of any PVB is to stop a__________.
Siphon
An indication that a pressure vacuum breaker is undersized for its application is
chatter or noise during flow
When using the one hose test on a PVB ,how many of the shut off valves must be closed?
Both
Pressure vacuum breaker shut offs and test cocks will avoid freeze damage if winterized by________________
rotating the ballvalves handles to a 45 degree angle
If not marked , a pressure vacuum breaker’s critical level is
the bottom of the valve body
What is the most common use for a pressure vacuum breaker?
Irrigation system
A spill -resistant vacuum breaker’s check valve must be drip tight at ____ PSID.
1 PSID
The required minimum number of resilient seated valves in an SVB is
two
The closing & opening pressure of a spill-resistant vacuum breaker’s vent valve is _____PSID
1 PSID
An SVB ‘s critical level must be above the downstream use by at least _____ inches?
12 inches
A spill- resistant vacuum breaker assembly has how many test cocks?
one test cock
The SVB may be subjected to _______ water pressure.
continuous
The SVB must not be installed in areas containing _____ fumes.
toxic
How must the SVB be installed according to the manufacturer?
Upright & Plumb
Which valves of the SVB must be closed when performing the one hose test procedure?
Both valves
What application was the SVB specifically designed to solve in the plumbing system.
X-ray development lab in a Hospital
How many test cocks does a Double check detector assembly have as part as the assembly?
eight
What is the minimum PSID of the #one check on a DC?
1 PSID
