I'm interested in hard piping the sprinkler system drain down pipe into the 6" sewer via a closed system.
My inspector can't tell me why I can't and says I need to build a 4" stand pipe with a wet trap. This will use a lot of water throughout the years just to keep the trap wet and will only be used once a year. Why can't I hard pipe the drain into waste and avoid the air gap with a wet trap? I would welcome any comments from anyone. Submitted anonymously and posted for discussion. Discuss This | Submit Your Question | Subscribe
9 Comments
Jonathan Sullivan
8/6/2020 10:25:53 am
The plumbing code won't allow a direct connection to the drain. This is another layer of backflow prevention.
Reply
Matt Cornell
8/6/2020 10:57:30 am
Mr. Sullivan is absolutely correct. If you are wanting to conserve water the mechanical seal is best. Take a look at the Sure Seal by Rectorseal SS2009V
Reply
Jonathan Sullivan
8/6/2020 11:16:54 am
Thanks Matt. I too prefer an seal, less moving parts. Just make sure it's ASSE 1072 conforming.
Brian Gerdwagen FPE
8/6/2020 11:00:07 am
There are two problems I have encountered:
Reply
Glenn S Berger
8/6/2020 11:46:41 am
Agree with Mr. Sullivan, having the air gap also gives you visual indication that the system is draining. I do not recommend discharging over a flat floor drain, provide funnel drain connection and locate where tripping can be minimized.
Reply
Sue
8/6/2020 02:38:31 pm
Where I work, the only places you can discharge a fire sprinkler system is into a landscaped area, an approved bio-swale with erosion protection or to sanitary with the approval of the Sanitary agency. We are no longer allowed to flow directly to storm because of the issues of pollution. When going into the sanitary system it has to be with an air gap or a wet trap. The flow of the fire sprinkler system must be taken into consideration when using an air gap because they can splash all over the room.
Reply
Jonathan Sullivan
8/7/2020 06:51:17 am
Sue - what jurisdiction is this? What specific pollution issues are encountered here? Is the sanitary system also overwhelmed?
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Mike
8/7/2020 09:41:09 am
Wet traps stop sewer vapors from entering the building.
Reply
Brad K
8/7/2020 10:39:29 am
System drain connection are the sprinkler design responsibility as pertains to NFPA 13-8.16.2.4...and on.
Reply
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