Potter Releasing Systems - Manual (Page 44)

44
Annually be done in the Spring after freezing weather, with the water supply control
(continued) valve only partially open. Once the valve trips, the water control valve can
be quickly closed so that the system is not filled with water. (Caution: Some
dry pipe valves will not operate properly without an adequate flow of water
to fully lift the clapper valve.) The valve is tripped by opening the inspector’s
test valve which releases air pressure within the system.
After the test, open the 2-inch main drain valve to drain the system. Remove
the valve cover and thoroughly clean the valve interior. Renew worn or
damaged parts as required, reset the valve, and replace the cover.
Add priming water and open the air supply to fill the system with air.
When the air pressure has reached its proper level, open the 2-inch main
drain to reduce the chance of a water hammer tripping the system,
then slowly open the water supply valve. When the water supply valve is
fully open, slowly close the 2-inch main drain.
Every 3 years Trip test the dry pipe valve.
The dry pipe valve should be trip tested with the water supply valve fully
open. The test should be terminated when clean water flows from the
inspector’s test connection.
A full trip test should also be conducted whenever the sprinkler system
undergoes a major alteration or extension.
Every 5 years All Sprinkler Systems:
Remove a representative sample of sprinklers with temperature classifi cation
of Extra High (325ºF or 163ºC) or greater which are located in an area in
which the temperature frequently exceeds the maximum al lowable ceiling
temperature. (See Table 2-1.) Provide new sprinklers of the same rating to
replace the removed sprinklers. The removed sprin klers should be sent to a
laboratory for operational testing in accord ance with NFPA 13. If sprinklers
fall to perform satisfactorily during the operational tests, all of the Extra
High and higher temperature heads should be replaced with new sprinklers of
similar rating.
Every 50 years Remove a representative sample of sprinklers from service and provide
new sprinklers in their place. Send the removed sprinklers to a testing
lab for operational testing in accordance with NFPA 13. If the sprinklers
fail to perform satisfactorily during the operational tests, all of them
should be replaced with new sprinklers of similar rating. After the 50-
year operational test, the test should be repeated every 10 years.
Note: A representative sample consists of the larger of:
A. Two sprinklers per floor or individual riser but not fewer than a
total of four, or
B. One percent of the number of sprinklers per individual sprinkler
system.