MeyerFire
  • Blog
  • Forum
  • PE Exam
    • PE Forum & Errata
    • PE Problems
    • PE Store
    • PE Tools
    • PE Prep Series
  • TOOLS
    • TOOLKIT (FREE TRIAL)
    • *TOOLKIT (PURCHASE)
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND
    • FIRE PUMP ANALYZER
    • FIRE PUMP DATABASE*
    • FIRE FLOW CALCULATOR*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'19)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • REMOTE AREA ANALYZER
    • QUICK RESPONSE AREA REDUCTION
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • TOOLKIT
  • LOGIN
  • STORE
  • About
Picture
ALL THINGS FIRE PROTECTION | SUBSCRIBE NOW

Why Not Hard Pipe Sprinkler Drain to Sewer?

8/6/2020

9 Comments

 
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.

This type of discharge is an indirect waste and requires an air gap or air break depending on how it is classified, ie potable or non-potable.

This must discharge into a waste receptor (floor drain, sump, mop sink, etc) that has a wet trap.

You then have two options to protect the trap as it won't be used often, either a trap seal or a trap primer.

See IPC 802 for indirect waste requirements and 1002.4.1 for trap seal protection.

Don't forget you also need fixture venting.

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.

And if permitted a bit of mineral oil.

Brian Gerdwagen FPE
8/6/2020 11:00:07 am

There are two problems I have encountered:
1 - Local water company wants the sprinkler to drain to storm since the water is unmetered and they do not get revenue to pay for the cost of treating it.
2 - Local water company cares about the environment and wants to treat the water instead of dumping it in the storm water flow, so it needs to go to sanitary.

Either option should have an airgap so that pressure does not build up and sprinkler water flows out of the air vents elsewhere in the building. I would never use a wet trap. If a trap is used, a mechanical trap seal would be my recommendation.

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?

Reply
Mike
8/7/2020 09:41:09 am

Wet traps stop sewer vapors from entering the building.

Have never seen a hard piped drain before in the manner you describe.

TBO designing a drain connection is really out of your scope as a fire sprinkler technician. This would be the mechanical or plumbing engineers responsiblility.

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.
Also 8.16.2.6.1 (2010-16) prohibits this connection specifically.
see also 8.16.2.6.2

Things to consider for system drains:
-Main drain tests and inspector tests can be overwhelming for some plumbing due to pressures and flows involved.
-Visual confirmation of drain water is typically preferred for system testing and service.

Reply



Leave a Reply.

    Jump to: Daily Posts
    Jump to: PE Problems
    Picture
    Why Sponsor?

    Free Signup

    Subscribe and learn something new each day:
    I'm Interested In:

    Community

    Thank You to Our Top
    ​February '21 Contributors!
    1. Dan W.
    2. Franck
    3. Jesse
    4. CJ B.
    ​5. Brian G.
    6. Mike
    7. Matt
    8. Casey M.
    9. Jay R.
    10. Glenn B.

    Your Post

    SUBMIT A QUESTION

    The Toolkit

    Sprinkler Designer or Engineer?
    ​
    ​Get all of our tools, including the Sprinkler Database, Friction Loss Calculator, Fire Pump Analyzer and more:
    Picture
    FREE 30-DAY TRIAL
    GET THE TOOLKIT

    Filters

    All
    ABA
    ADA
    ASCE 7
    ASME A17.1
    Daily Discussion
    Design Documents
    Explosion Protection & Prevention
    Fire Detection And Alarm Systems
    Fire Dynamics
    Flammable & Combustible LIquids
    FM Global
    Human Behavior
    IBC
    IFC
    Information Sources For Analysis
    IRC
    Means Of Egress
    NFPA 1
    NFPA 10
    NFPA 101
    NFPA 11
    NFPA 110
    NFPA 12
    NFPA 13
    NFPA 13D
    NFPA 13R
    NFPA 14
    NFPA 15
    NFPA 17A
    NFPA 20
    NFPA 2001
    NFPA 214
    NFPA 22
    NFPA 24
    NFPA 25
    NFPA 291
    NFPA 30
    NFPA 33
    NFPA 400
    NFPA 415
    NFPA 497
    NFPA 5000
    NFPA 502
    NFPA 54
    NFPA 55
    NFPA 654
    NFPA 68
    NFPA 70
    NFPA 72
    NFPA 92
    NICET
    Passive Building Systems
    PE Prep Guide
    PE Prep Series
    PE Sample Problems
    Poll
    Smoke Management Systems
    Special Hazard Systems
    Types Of Analysis
    UFC 3 600 01
    UFC 3-600-01
    Updates
    Water Based Fire Suppression
    Weekly Exams


    Archives

    March 2021
    February 2021
    January 2021
    December 2020
    November 2020
    October 2020
    September 2020
    August 2020
    July 2020
    June 2020
    May 2020
    April 2020
    March 2020
    February 2020
    January 2020
    December 2019
    November 2019
    October 2019
    September 2019
    August 2019
    July 2019
    June 2019
    May 2019
    April 2019
    March 2019
    February 2019
    January 2019
    December 2018
    November 2018
    October 2018
    September 2018
    August 2018
    July 2018
    June 2018
    May 2018
    November 2017
    October 2017
    September 2017
    August 2017
    July 2017
    June 2017
    November 2016
    October 2016
    July 2016
    June 2016


    Daily
    Daily discussions are open-ended fire protection, fire alarm, and life safety questions submitted anonymously for the benefit of sharing expertise and learning from other perspectives. Anyone can submit a question here:
    SUBMIT A QUESTION

    Exam Prep

    Picture
    2020 PE Prep Guide​
    ​(Available Now!)
    Picture
    PE Prep Series
    ​(Available Now!)
    2020 PE Prep Series
    Current Leaderboard
    ​(Click to enlarge)
    Fire Protection PE Exam Prep

    PE Problems
    ​Visit July-October for daily Fire Protection PE Exam sample questions.

    Solutions are posted the day after posting.

    Comment with your solutions, questions or clarifications.

    Please note that questions posted are unofficial and in accordance with NCEES rules are intended to be similar to actual exam questions, not actual exam questions themselves.

    RSS Feed

Picture
Home - About - Blog - Contact - Exam Prep - Store

​Copyright © 2021 MeyerFire, LLC

The views, opinions, and information found on this site represent solely the author shown and do not represent the opinions of any other party, nor does the presented material assume responsibility for its use. Fire protection and life safety systems constitute a critical component for public health and safety and you should consult with a licensed professional for proper design and code adherence. Some (not all) outbound links on this website, such as Amazon links, are affiliate-based where we receive a commission for orders placed elsewhere.
  • Blog
  • Forum
  • PE Exam
    • PE Forum & Errata
    • PE Problems
    • PE Store
    • PE Tools
    • PE Prep Series
  • TOOLS
    • TOOLKIT (FREE TRIAL)
    • *TOOLKIT (PURCHASE)
    • SUBMIT AN IDEA
    • BACKFLOW DATABASE*
    • CLEAN AGENT ESTIMATOR
    • CLOUD CEILING CALCULATOR
    • DOMESTIC DEMAND
    • FIRE PUMP ANALYZER
    • FIRE PUMP DATABASE*
    • FIRE FLOW CALCULATOR*
    • FRICTION LOSS CALCULATOR
    • HANGER SPACER
    • IBC TRANSLATOR*
    • K-FACTOR SELECTOR
    • NFPA 13 EDITION TRANSLATOR ('19 ONLY)
    • NFPA 13 EDITION TRANSLATOR ('99-'19)*
    • LIQUIDS ANALYZER*
    • OBSTRUCTION CALCULATOR
    • OBSTRUCTIONS AGAINST WALL*
    • PLUMBING FIXTURE COUNTS
    • REMOTE AREA ANALYZER
    • QUICK RESPONSE AREA REDUCTION
    • SPRINKLER DATABASE*
    • SPRINKLER FLOW*
    • TEST & DRAIN CALCULATOR
    • THRUST BLOCK CALCULATOR
    • TRAPEZE CALCULATOR
    • UNIT CONVERTER
    • VOLUME & COMPRESSOR CALCULATOR
    • WATER SUPPLY (US)
    • WATER SUPPLY (METRIC)
  • TOOLKIT
  • LOGIN
  • STORE
  • About