Sprinkler

Discuss & collaborate on issues of public safety and fire prevention.
surewin
Posts: 6
Joined: Wed Dec 31, 1969 7:33 pm

Sprinkler

Postby surewin » Fri Jul 30, 2010 2:47 pm

Wet Sprinkler System

System side pressure and supply side pressure are the same? Do you guys know what's causing this? Also, it's equipped with a backflow preventer. I suspect this might be the cause but wanted other opinions. Also, what is the solution? conducting a 2 inch drain test?

CKL958
Posts: 310
Joined: Wed Dec 31, 1969 7:33 pm

Postby CKL958 » Fri Jul 30, 2010 7:47 pm

"surewin" wrote:Wet Sprinkler System

System side pressure and supply side pressure are the same? Do you guys know what's causing this? Also, it's equipped with a backflow preventer. I suspect this might be the cause but wanted other opinions. Also, what is the solution? conducting a 2 inch drain test?


If an attempt has been made to bring the system pressure up and it does not rise, you have a leak. I wouldn't so much suspect the backflow as a leaking drain valve, or a gasket on the flapper not seating properly. The backflow is on the city side of the system - it will have no effect on the building side of the system holding pressure.
CKL958

"We're all in this together"
- Steve "Red Green" Smith

infernobuster
Posts: 505
Joined: Wed Dec 31, 1969 7:33 pm

Postby infernobuster » Fri Jul 30, 2010 10:35 pm

A few things i would check ..

- a possible leak at the inspector test site
- a leak in the system itself
- bad jockey pump or bad jockey pump lines
- faulty gauges ( they have to be swapped out every 5 years)
All men are created equal, a few become fire fighters.

sugar
Posts: 56
Joined: Wed Dec 31, 1969 7:33 pm

Postby sugar » Sat Jul 31, 2010 4:36 pm

is there an alarm valve or just a manifold with a flow switch and test and drain? New or old system??

gfd31
Posts: 48
Joined: Wed Dec 31, 1969 7:33 pm

Postby gfd31 » Sat Jul 31, 2010 8:32 pm

What is the "system pressure" supposed to be?

It is possible to have both the "city pressure" and the "system pressure" to be the same, or relatively close.

If there was a leak, or even a problem with the backflow preventer the system would have "flow" and the alarm should be sounding, and if it's connected to a fire alarm system you should have either a supervisory or a trouble on the FACP at the very least.

CKL958
Posts: 310
Joined: Wed Dec 31, 1969 7:33 pm

Postby CKL958 » Sat Jul 31, 2010 9:48 pm

"gfd31" wrote:If there was a leak, or even a problem with the backflow preventer the system would have "flow" and the alarm should be sounding, and if it's connected to a fire alarm system you should have either a supervisory or a trouble on the FACP at the very least.


Flow switches generally wouldn't trip for water travelling backwards in the system. They are a spring return paddle that closes contacts when pushed. Therefore, water travelling towards the city would be pushing back to the "normal" position, and would not cause an alarm.

In a system that utilizes a pressure switch on the alarm line to detect flow, the main alarm valve would have to be open to allow water into the alarm line to create an alarm.

The backflow would be the absolute last place I would be looking. The pressure has to leak through the alarm valve to pass back into the city supply.
CKL958



"We're all in this together"

- Steve "Red Green" Smith


Who is online

Users browsing this forum: No registered users and 4 guests