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Sprinkler System Terminology Questions and
Correct Answers
Heads Ans: — series of nozzle like devices
Riser Ans: — Vertical piping that feed the cross main and contain
system control valves
Cross Mains Ans: — serves the branch lines
branch lines Ans: — where the sprinklers are directly installed
Three types of release mechanisms for sprinkler heads Ans: —
Fusible Links
Glass (frangible bulb)
Chemical Pellets
Types of sprinkler heads Ans: — Upright
Pendant
Sidewall
Special Sprinkler Heads
Main Control Valves Ans: — Outside Screw and Yoke (OS&Y)
Post Indicator Valve (PIV)
Post Indicator Valve Assemble ((PIVA)
Wall Post Indicator Valve (WPIV)
What are Control Valves? Ans: — Control valves are valves used to
cut off the water supply to the system or zone when it is necessary
to perform maintenance, change sprinkler heads, or interrupt
operation. These valves must be indication valves.
What is an OS&Y Valve Ans: — Outside Screw and Yoke valves
have a yoke on the outside with a thread stem or screw. The
threaded portion of the stem is out of the yoke when the valve is
open and inside when the valve is closed.
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What is a PIV Valve? Ans: — Post Indicator Valves are hollow
posts. The valve stem has a target where the words "open",
"closed" or "shut" appear.
What is a WPIV? Ans: — Wall Post Indicator Valves are the same as
Post indicator valves except it is located on the wall, most
frequently in warehouses.
Where is the FDC location for the building? Ans: — Outside wall of
building where the riser room is located.
What type of protection device will be seen on the FDC? Ans: —
Either plastic caps or knox caps
Why do FDCs have protection devices on them? Ans: — To keep
arsonists from interfering with the device, as well as to keep birds
out and to prevent people from stuffing debris inside
How do you get the caps off an FDC? Ans: — Plastic caps can be
center broken with a spanner wrench. The eye bolts can also be
pried off with the spanner. If knox caps, use the knox key.
Where will the knox key be located? Ans: — Underneath the
Officer's seat in the cab, and in driver 1 compartment
What pressure does the driver need to pump to when pumping to
an FDC? Ans: — 150 PSI + 5 additional PSI for each floor
If you are called out to a location for a water flow alarm and you
discover that the water gong is ringing with water flowing from its
drain what would this indicate? Ans: — Water is flowing
somewhere in the system.
If you are called to a location for a water flow alarm and arrive to
find the water gong is silent but a small puddle of water is on the
ground under the drain what would this indicate? Ans: — Possible
water surge in the system setting off a false alarm
The following are the four basic components that make up a
sprinkler system. What do these each do/what are they?
a) water supply main
b) riser
© 2025 All rights reserved
Sprinkler System Terminology Questions and
Correct Answers
Heads Ans: — series of nozzle like devices
Riser Ans: — Vertical piping that feed the cross main and contain
system control valves
Cross Mains Ans: — serves the branch lines
branch lines Ans: — where the sprinklers are directly installed
Three types of release mechanisms for sprinkler heads Ans: —
Fusible Links
Glass (frangible bulb)
Chemical Pellets
Types of sprinkler heads Ans: — Upright
Pendant
Sidewall
Special Sprinkler Heads
Main Control Valves Ans: — Outside Screw and Yoke (OS&Y)
Post Indicator Valve (PIV)
Post Indicator Valve Assemble ((PIVA)
Wall Post Indicator Valve (WPIV)
What are Control Valves? Ans: — Control valves are valves used to
cut off the water supply to the system or zone when it is necessary
to perform maintenance, change sprinkler heads, or interrupt
operation. These valves must be indication valves.
What is an OS&Y Valve Ans: — Outside Screw and Yoke valves
have a yoke on the outside with a thread stem or screw. The
threaded portion of the stem is out of the yoke when the valve is
open and inside when the valve is closed.
© 2025 All rights reserved
, 2 | Page
What is a PIV Valve? Ans: — Post Indicator Valves are hollow
posts. The valve stem has a target where the words "open",
"closed" or "shut" appear.
What is a WPIV? Ans: — Wall Post Indicator Valves are the same as
Post indicator valves except it is located on the wall, most
frequently in warehouses.
Where is the FDC location for the building? Ans: — Outside wall of
building where the riser room is located.
What type of protection device will be seen on the FDC? Ans: —
Either plastic caps or knox caps
Why do FDCs have protection devices on them? Ans: — To keep
arsonists from interfering with the device, as well as to keep birds
out and to prevent people from stuffing debris inside
How do you get the caps off an FDC? Ans: — Plastic caps can be
center broken with a spanner wrench. The eye bolts can also be
pried off with the spanner. If knox caps, use the knox key.
Where will the knox key be located? Ans: — Underneath the
Officer's seat in the cab, and in driver 1 compartment
What pressure does the driver need to pump to when pumping to
an FDC? Ans: — 150 PSI + 5 additional PSI for each floor
If you are called out to a location for a water flow alarm and you
discover that the water gong is ringing with water flowing from its
drain what would this indicate? Ans: — Water is flowing
somewhere in the system.
If you are called to a location for a water flow alarm and arrive to
find the water gong is silent but a small puddle of water is on the
ground under the drain what would this indicate? Ans: — Possible
water surge in the system setting off a false alarm
The following are the four basic components that make up a
sprinkler system. What do these each do/what are they?
a) water supply main
b) riser
© 2025 All rights reserved
