Low Pressure (300 psi) CO2 Pressure Test Requirements

[BillyNuclear]

I'm replacing a pilot operated valve that will require cutting the piping on both sides of the valve in order to replace it. We'll end up with a new weld on the upstream and downstream side of the valve. The valve is normally pressurized on the upstream side, but not the downstream side. The downstream side is only pressurized if the system is discharged. My question is, are either of these welds required to be pressure tested? Would it be at normal operating pressure or some percentage above normal? If a pressure test is required, is there an out? Like maybe a dye penetrant test in lieu of pressure test? What standard and section would this be called out in in the NFPA? Thanks.

 

[stookeyfpe]

You need to obtain a copy of NFPA 12 and review the requirements in Section 4.4 through 4.7. And if your thinking about asking me for a copy, please don't because its a copyrighted document.

 

[BillyNuclear]

I have read through those sections. It's written very general. Not specific. The only section that really tells you anything is the section about Marine Systems. It actually tells you to pressurize the piping from the tank to the nozzles to a specified pressure and that some amount of leakage is acceptable from the tank shut off valve to the nozzles. You get not such instruction from any of the other sections as best I can tell. Maybe I'm missing something? Are you to refer to ANSI B31.1?