Block Valve in the Relieving Path of Fixed CO2 Extinguishing System 1

[ripaldee]

NFPA 12 requires the installation of pressure relief device in closed piping sections of the fixed CO2 extinguishing system. My question is: Does the standard requires a block valve in the relieving path of the pressure relief device?

 

[BigInch]

I can't be sure, not having read NFPA, but I've not seen where any code reqires a block valve in front of a relief valve, no matter how much some people like to put them there.

If you do put one there, be sure you can seal-lock it open.

We will design everything from now on using only S.I. units ... except for the pipe diameter. Unk. British engineer