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Hi Greg, Some safety considerations with R717. 3 to 5ppm is a ammonia smell.
30ppm you need a respritor
OSHA allows 5 minutes exposure at 50ppm
It's a life hazzard at 5000ppm
It's flamable at 150,000ppm to 270,000ppm
It's pressue at 75*f is 126psi and 300psi@125*f a typical condensor pressure. Water is the key for contamination removal and use alot of water. Ammonia lung burns do not heal well nor fast. Never rub your eyes and use sweat head bands. This is a short list of some of the considereations. I would hope the plant safety manger would give the crew a safety talk before work begins. R717 piping is considered high pressure piping. It does not like copper, bronze or there alloys. Since your flowmeter is probably brass you need to find a steel gauge or plan on replacing the gauge. Your welding leads will deterioate after use so use old leads if you have them. Code calls for all high pressure piping to be Tig welded 2" diameter and smaller and root pass on 2" and larger. A, AR purge of 5cft/hr is required. I strongly suggest no Mig on the piping welds. To easy to get a pin hole that will a bitch-to fix latter. I would do a low dry nitrogen pressure test of 150psi for 15 minutes without a gauge movement befoe I would call "leak free". The plant refer man would be able to help you here. You can use Co2 for pressure checks but nitrogen also removes moister and is a stable gas. I'm allergic to ammonia so I never got to work on used systems so I can't help you anymore than what I've told you. T_Bone
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