Wet Systems

Question 1

how it sounds an alarm

Answer 1

alarm valve or vane type flow switch to sound an alarm

Question 2

water temperature minimum

Answer 2

4 degrees

Question 3

relief valves

Answer 3

every wet system needs to have a relief valve

Question 4

air venting

Answer 4

shall be in a high point in the system
methods:
1. manual valve, minimum 1/2" size
2.automatic air vent
3.remote inspectors test valve
4.other approved means

Question 5

vane type flow switch

Answer 5

has a vane(paddle)

flowing water sends signal to fire alarm system panel and/or electrical bell, causing the audible alarm.

Question 6

clapper

Answer 6

system pressure holds it closed and it opens when system pressure drops

Question 7

intermediate chamber

Answer 7

when the clapper opens water flows into the intermediate chamber and to the alarms

Question 8

main drain connection

Answer 8

tapped into the valve housing, which is above the clapper. It should allow full flow to test the system

Question 9

alarm test valves

Answer 9

connected to a threaded outlet (Port) below the clapper on the alarm valve housing.

• providers a means to test the operation of alarm devices, without tripping the alarm valve(opening the clapper)

Question 10

alarm line valve

Answer 10

connected to the threaded outlet (port) which is supplied for discharge from the intermediate chamber on the alarm valve housing

Question 11

check valve

Answer 11

this valve allows water to flow into the system and does not allow water to flow backwards

Question 12

restricted orifice

Answer 12

the restricted orifice is used to restrict the flow to the drain out of the intermediate chamber, which forces the water to flow out to the alarm device.

Question 13

alarm pressure water flow switches

Answer 13

installed on the alarm line, downstream of the alarm line and alarm test shut-off valves. These switches detect the flow of water and send an electronic signal.

Question 14

Alarm test valve external bypass

Answer 14

water hammer could potentially open the clapper. This bypass allows water to come from the supply side to the system side to keep pressure higher on the system side at all times.

Question 15

low-pressure switches

Answer 15

installed on the system side of the alarm check valve clapper and are attached to piping that cannot be isolated.

Sends a trouble signal or supervisory that the system is losing pressure.

Question 16

water motor gong

Answer 16

makes the audible alarm

Question 17

strainers

Answer 17

installed prior to the water jet orifice of the water motor gong

Question 18

water pressure gauges

Answer 18

above and below alarm valve.
system pressure
supply pressure.

Question 19

Preventing false alarms

Answer 19

Retard chamber
external by-pass
constant pressure(pump)

Question 20

Service on wet system

Answer 20

phone monitoring company
close supply valve
close alarm line valve and alarm test valve
close excess pressure pump valve
open drain

Question 21

gauges

Answer 21

cannot be smaller than 1/4 inch

shall have a maximum limit not less than twice the normal system working pressure

Question 22

alarm line

Answer 22

has to be a minimum 3/4 inch corrosive resistant pipe
maximum length 75 feet
maximum rise 20 feet