Hydrostatic Test on addition to existing freezer

[SprinklerDesigner2]

Picture an existing 20,000 sq ft industrial freezer where 30 years ago the fire sprinkler contractor did not fully sprinkler the building.

Decades later the local authority having jurisdiction requires additional sprinklers, about 60 heads, be added to this freezer and now he wants to see a hydrostatic test.

It's a standard dry system and when it has tripped in the past they simply take the pipe outside to let it thaw out.

We can't heat the building because frost under the slab will heave and most likely destroy the building. I can not see how we can do a hydro. I know, we have to destroy the building to save it with sprinklers?

Is there anywhere I can find a saving grace on this rather peculiar situation?

 

[skdesigner]

Pump in antifreeze solution, hydro it, then drain the antifreeze solution?

 

[SprinklerDesigner2]

Yes, that would work and something to think about but what about the full trip test?

 

[skdesigner]

Good question. Make sure the pipe is all graded properly, and then as soon as water hits the inspector's test, shut the control valve and crack the main drain as fast as possible? Probably would involve some of the aforementioned removal and outdoor-thawing of the pipe if it doesn't drain fast enough.

You could always go for the up-sell, convert it to a single-interlock pre-action and tell the owner he'll never have to worry about flooding the system again... unless there's a fire, of course.

 

[SprinklerDesigner2]

Even with the up-sell I still have to hydro the system and there is no way they will shut the system down to warm the building up.

And yes, the valve trips, the pipe is taken apart to thaw but what about the hydro after it is put back together again?

 

[skdesigner]

Valid points my good man. Best of luck with it.

 

[cdafd]

What does 13 say about doing a air test only,in freezing weather??

Does it say do the air till it warms up, or air test is good enough?

Not near the book.

Yes I saw a company try to anti freeze a deep freeze warehouse once, took a number of tries before it passed, plus a lot of anti freeze

I take it this is a freezer for food?? The one I saw had to use food grade anti freeze

 

[cdafd]

13 says hydro test regardless.

Can they some how isolate the new stuff and only test that?

Or set down with someone and try some common sense, that kind of not testable??


Can you use this out of 25, to argue that a hydro should not be done??

13.4.5.2.2.1


Dry pipe valves protecting freezers shall be trip tested in a manner that does not introduce moisture into the piping in the freezers.

 

[cdafd]

Maybe see what answer you get from here::

http://www.nfsa.org/?page=EOD

 

[cdafd]

FM have any guidance??

 

[fireguy519345]

Dry pipe valves protecting freezers shall be trip tested in a manner that does not introduce moisture into the piping in the freezers.

1. We have added a sectional valve to shut off the piping to the freezer. The valve was locked or monitered
2. Most of the freezers we have serviced have dry heads
3. Signs were added to remind us of the purpose of the valve, and if the system was wet, dry, an antifreeze loop, and what kind of antifreeze

 

[chicopee]

Heater strips on the pipes may be an answer during a hydro. Would be expensive and an installation headache.