Wet, Dry & Anti-Freeze Systems Flashcards
Wet system pressure gauge connection to be no smaller then
1/4”
Which gauge cannot be calibrated
Standard gauge
Relief valves are to be a minimum of what size and what pressure
1/2” in size, 175psi or 10 psi over system pressure, whichever is greater
Air venting is required on
All systems using metallic piping
Air vent manual valve to be a minimum of ___ in size
1/2”
What is the purpose of air venting a wet system
Get rid of as much trapped air as possible, minimize corrosion, microbial activity
Wet system low point drain less then 5 gallons
1/2 plug or cap
Full draining via removal of single pendant
Easily separated flex coupling
Wet system, low point on system more then 5, less then 50 gal
3/4 valve
Wet system, low point on system larger then 50 gals
1” valve
How often should drain connections be tested
Annually or as needed
Main drain tests, what is the percentage of reduction in flow pressure that shall be corrected
10%
How often are alarm devices to be tested
Quarterly
Hydraulic nameplate is required to have
All hydraulically calculated wet systems / inspect monthly
Anti freeze information sign shall indicate
Location of anti freeze system
Location of Auxiliary&low points
Dry system air shall be able to be restored in ______ minutes (above -15C)
30 minutes
Dry system air shall be able to be restored in ______ minutes (below -15C)
60 minutes
Air supply connections shall be a minimum of what size
1/2”
Air supply must enter the valve
Above priming level
What’s the purpose of an air maintenance device
To control pressure and air flow
Where is an air maintenance device not required
When a compressor has a capacity of less then 5.5ft3 at 10psi
How many dry pipe valves per air maintenance devices
One
What is required when using a stored supply to refill a dry system
A low pressure alarm
When nitrogen is coming from a stored supply what must be used
A pressure regulator
Dwelling units ITV delivery time
15 seconds
500 and gallons and less, ITV delivery requirements
No quick opening device required, no required delivery time
750 gallons and less ITV water delivery requirements
QOD permitted, no required delivery time
ITV min pipe size
1”
Air pressure in dry system shall be
Based off manufacturer literature or 20 psi above trip
Check valves used for subdivisions shall have a ____ hole drilled in the clapper to allow for equalization
1/8”
What kind of system is gridded permitted in
Wet only
Tie in drains for dry pipe systems shall be
1”
Areas subjected to freezing, what is the pitch
Mains - 1/4” per 10’
Brand lines - 1/2” per 10’
Auxiliary drains located in refrigerated areas shall not be smaller then
1”
Minimum size nipple for drump drip
2”x12”
Where is FDC installed on a dry pipe system
Between the system control valve and the dry pipe valve
Dry system air test consists of
40 psi for 24 hours
Leakage in dry system air test cannot be more then
1-1/2 psi
Dry system integrity test is
40 psi 2 hours
System operational test is performed through the
ITV
Refrigerated area temperature is
Any area maintained below 0 degrees Celsius (32F)
Pipe pitch in refrigerated areas shall be
1/2” per 10’ on all pipe
Air supply in a refrigerated area must have
2 supply’s, minimum of 1” in diameter
What temp requires a dry pipe/pre action system to be installed
4 degrees Celsius or 40 F
Max size of wet system in light and ordinary hazard
52,000ft2
Max size of extra hazard scheduled system
25 000ft2
Max size of extra hazard, hydraulically calculated and high piled storage
40 000ft2
What should the size of the floor drain in the valve room be
Twice the diameter of the main drain pipe
Adequate clearance in valve rooms is
3’0 around valve
4’0 in heated enclosure
What is used to measure the freezing point in an anti freeze system
Ratractometre
What is a ratractometre calibrated with
Distilled water
