In a current project, we have ordered a set of cast iron vertical pumps as per NFPA Standard. The specific standard does not mention a thing about allowable loads at nozzles and the values given by the vendor are almost half the values indicated at API610. It’s the Fire fighting system with Design Temp 70oC, Pressure 16.8barg and 12” discharge nozzle diameter. I lean towards using rubber compensator.
As far as I have searched NFPA Standard for the Installation of Stationary Pumps for Fire Protection I haven’t find any restrictions using rubber compensations or expansion joints in general.
Have any of you have found such a restriction due to safety reasons, in NFPA or in any other code or standard that you are using for fire fighting systems?

Thanks in advance
Kyriakos.

Your company or client loss control experts should help you regarding use of rubber joints. If they agree, then why not ? I would recommend use of tie bars.

Thanks for the reply.
Your suggestion is correct but it’s about pressure thrust loads. My question was if you have ever came across in any code or standard a restriction in using rubber compensators at fire fighting systems, due to the fact that rubber is flammable.
Thanks again,
Kyriakos

Like I said, this is for others to decide. That said, firewater pumps are frequently located in a safe area, so may not need protection themselves. In that case I would suggest that a rubber EXJ is ok.