×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Provision of Globe Valves In Fire Water System

Provision of Globe Valves In Fire Water System

Provision of Globe Valves In Fire Water System

(OP)
Hi,

I am working on one project in which process and safety Department have used Globe Valve in Fire Water System for PCV bypass on recycle line from the pump discharge header back to the suction source of the pumps. Refer to NFPA section 6.1.1: All valves controlling connections to water supplies and to supply pipes to water-based fire protection systems shall be listed indicating valves. We could not find any Globe Valve available in market with UL/FM approved. Also I could not find any FM approval procedure for Globe Valve.

Can anyone provide expert opinion on this issue, whether we can use Globe Valves in FW water system as this is usually considered as non indicating type valves. I have seen some provision of globe valve in NFPA-20 on drains Refer NFPA-20 Fig: A.4.31(a).

RE: Provision of Globe Valves In Fire Water System

The Cla-Val Pressure Relief Valves are designed specifically for fire protection pumping systems and are available in a variety of configurations and end connections. These are automatic glove valves.

Cla-Val

RE: Provision of Globe Valves In Fire Water System

(OP)
Thanks for your response. However, We require manual globe valve on the bypass of PCV with UL listed and FM approved.

RE: Provision of Globe Valves In Fire Water System

Which NFPA code do you refer to above - there are lot of them!

Generally NFPA systems treat pumps appallingly and have no return line or min flow bypass in many systems I've seen. I've seen large fire water pumps regularly (weekly) fired up and run for 15 minutes at dead head to prove the system. Heaven only knows what this does to the pump, but NFPA doesn't seem to care. If your process and safety dept are looking at this like any other process system, they need to think again. NFPA work in an alternate universe and vendors work to a very very fixed design. You can ask for all sorts of changes and additions to make it like the way you design everything else and they just ignore you, at least in my experience...

I can only think they work on the basis that such valves can be set badly, can fail or can allow more water to pass than it should and just normally don't use flow or pressure regulating valves in their systems.

There is a specialist NFPA forum in the engineering codes heading. Try searching there or starting a new post on this subject there.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

RE: Provision of Globe Valves In Fire Water System

(OP)
Thanks LittleInch,

I forgot to mention, the reference Code is NFPA-24 section 6.1.1.

This recycling line is requirement of Client Safety Standard which cannot be avoided. This standard statement are as under:

Water pressure shall be controlled by recycling fire water from the pump discharge header back to the suction source of the pumps. The fire water pressure control system shall consist of a dedicated pressure transmitter, a pressure controller with adjustable set point, and at least two pressure control valves installed on the recycle manifold.
The pressure control valve system shall be sized to recycle a minimum flow of one half the design capacity of the smallest jockey pump and shall be designed to fail closed. The maximum recycle flow of the system shall be two times the sum of the design flows of one jockey pump plus the largest single fire water pump.

Therefore, In this case I dont think there is some way if we think again. Thanks for your guidance, I will definitely start new post on this subject on NFPA forum as well with some more details.

Regards.

RE: Provision of Globe Valves In Fire Water System

Good luck.

It sounds to me like a conflict between client spec and NFPA. If you want 100% compliance with NFPA you can't have that fancy looking pressure control system (at least AFAIK). Find out the details then it's up to the client what he want to do.

Fire systems really need to be very simple and essentially bullet proof. When it all needs to work in the dark, with no power or light and something on fire the last thing you want is your pressure control system throwing a hissy fit and opening up fully.... Hence you would need to make your pressure control system something like SIL3 standard - that's a lot of cash for something that isn't needed.

LI

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources