Security & Fire Protection Systems/Underground Fire main



Here in the UK we have  a large industrial , We have approx 2000m of HDPE welded pipe in our underground firemain. The pipe varies in 355 dia to 80 dia and there are sluice/gate valves installed for isolation purposes etc.
The client designers have confirmed the system is a completely welded system however the valves are mechanical joints (bolted) to the actual pipe.

I have read through NFPA 24 but there doesn't seem to be any advice in relation to using HDPE welded pipe and mechanical joints

For instance, as the valves are so large, do they require a concrete base?

The reason I ask, is that we have carried out sectional testing throughout the site main and areas that have passed previously are know failing.
We suspect that the HDPE pipe is expanding and moving under the 18 bar test pressure and there is nothing holding the valves in position. It is always at the valves  the pressure test fails.

Can you advise on any solutions or point me to some info showing I need bases for the valves?


Mr. Donegan~

This is an interesting issue and I have not been involved in a lot of underground issues such as yours. NFPA 24 isn't helping me either, but I will direct you to someone that may be more in tune with your issue as well as with UK above and beyond NFPA.

Mr. Alan Brinson of the European Fire Sprinkler Network can be reached at or
tel:   +44 (0) 20 8877 2600 and may be in tune with your situation technically as well as applicable UK standards and policies.

My apologies that I couldn't answer your question directly, but Mr. Brinson should be able to assist.

Thank you.

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Dominick G Kasmauskas


Can assist ONLY with WATER-Based FIRE Protection Systems, specifically fire sprinklers. Legislative issues, education, home fire sprinklers, where to find resources, and promoting fire sprinklers as "Green". Mostly NFPA 13, 13R, 13D, 14, 20, 24, 25, 101 and model building, residential, and fire codes.


Fire sprinklers, code enforcement, working with legislation, creating reports, presentations. Familiar with the LEED system. NY Regional Manager of the National Fire Sprinkler Assn. Member of two NFPA committees and the American Water Works Assn - Fire Protection Committee. I have done countless presentations and articles involving the fire sprinkler concept. Presently a memebr of the NY State subcommittee to the Codes Council for dwelling fire sprinklers.

NFPA, ICC, AWWA, SFPE, NYSBOC, NY Fire Marshals, Greater NYC FSDA, US Green Building Council.

NFPA Fire Service Section newsletter, SQ Magazine, NFSA Regional Reports.

Former NJ Certified Firefighter, Fire Inspector, Fire Official, and Fire Instructor. Presently an NFPA Certified Fire Protection Specialist and NY Certified Code Enforcement Official.

Awards and Honors
US Army- GCM, and Honorable Discharge. Fire Service- 2 commendations.

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