Wet and Dry Pipe Valves Flashcards
Vane type flow paddle will not operate ______
Water motor gong
Audible alarm must be heard within
5 minutes
Piping between the sprinkler system and pressure actuated alarm initiating device shall be
Non corrosive pipe, no smaller then 3/8”
Alarm line is to be auto drained through
A restricted orfice
Drain pipe on alarm line to be no smaller than
1/4”
Paddle type water flow alarm indicators shall be installed on _____
Wet systems only
PS10 switch is
Alarm switch, can be used on any system
PS120 is
Supervisory, low water pressure
Generally used on wet systems
PS40 is
Supervisory, Low air
Generally used on dry systems
The 3 different kinds of seating arrangements for alarm valves are
Split/Groove
Pilot Port
Divided ring
Which seating arrangement has grooved rings with a large channel for feeding alarm line
Split/Groove
Which seating arrangement has a separate clapper and larger opening to the alarm line that is prone to issues
Pilot Port
Which seating arrangement has 2 separate rings with small holes between the seats
Divided ring
Water motor gongs need
Constant water supply to operate
Piping for water motor gong can not be less than
3/4”
Maximum vertical distance WMG can be from alarm valve is
20’
Maximum horizontal distance WMG can be from alarm valve is
75’
Excess pressure pumps must be
Hardwired
Excess pressure pumps can either be
Manual or automatic
A retard chamber takes ______
Small surges from city supplies and discharges them to the drain
Where does a retard chamber generally vent through
Water motor gong pipe
A wet pipe system shall be provided with a relief valve no less then
1/2” in size and set to operate at 175psi
When are relief valves not required?
Where auxiliary air reservoirs are installed to absorb pressure increases
The 4 common types of dry pipe valves are
Differential
Latching differential
Mechanical
Low differential
What’s the difference between a differential dry pipe valve and a latching differential dry pipe valve?
Very similar, latching has a mechanical latch that assist the valve clapper to stay closed
What is the system air pressure in a low differential valve
15-20 psi above supply pressure
Low differential valves are not subject too
Water Column
Accelerators are to be installed as close ___
As practical to DPV
Where is the anti flooding device installed
Between accelerator and DPV
Drum drips are used where the capacity is over _____ in a dry system
5 gallons
Air shall be able to be restored in a system within ___ minutes (system above 5 degrees Fahrenheit)
30 minutes
Air shall be able to be restored in a system within ___ minutes (system below 5 degrees Fahrenheit)
60 minutes
Air supply is taken for a shop system w/ higher pressure then needed, what is required
A relief valve between outlet of the air maintenance device and the dry system and set to relieve 20 psi above the operating pressure
Dry pipe valves controlling systems larger then 500 gals are usually required to have a
Accelerator or exhauster
How does an accelerator work
Admits sprinkler system air to the intermediate chamber, located beneath the clapper of a differential type valve
How does an exhauster work
Uses the movement of the diaphragm to open an auxiliary valve, which discharges system air pressure into the atmosphere
Quick opening device is to be located
As close as practical to the dry pipe valve
What needs to be installed between the dry pipe riser and an accelerator
Composition disc glove valve
What must be installed between the QOD and intermediate chamber
Check valve
Trapped section with less than 5 gallons of water, what is required
Drain no smaller then 1/2” and a plug or nipple cap
Trapped section larger then 5 gal In a dry system, what is required
Auxiliary drain/drum drip assembly
The alarm valve primarily acts as a ____ _____ in a wet system
Check valve
Where is the pressure flow switch installed with an alarm valve equipped with a retard chamber
Above the retard chamber
What kind of pumps are excess pressure pumps
Positive displacement
Where must paddles be bent towards on a paddle flow switch
Towards the water flow
In a dry pipe valve, the intermediate chamber is always open through the _______
Velocity drop
Which valve does not latch upon opening, which can lead to the valve closing before it’s fully drained
Low differential
Low differential valves must have a _____ installed to protect system piping from freezing
High water level signalling device, or automatic drain
Electrical signals from an alarm valve can operate
Fans/exhausts, close doors, sound electric bells, buzzers, horns, and strobes
Air maintenance devices shall be tested
Annually, during DPV trip test
Excess pressure pump provides how much pressure above city
30-50psi
Paddle flow switch must be installed how far from a change of direction
6”
Paddle flow switch must be installed how far from a control valve
24”
