Ammonia PRV coated with green residue after release. 1

[ammoniachick]

We recently had a small release of ammonia from one of our Hansen Pressure Relief Valves. It released at 160 PSIG instead of 250, off of an Evaporative Condensor. When we took it apart, it was coated in a green powdery residue. I believe this was the cause for the release. But I can not figure out what it is or where it is coming from. Any ideas or suggestions?

 

[cloa]

Any copper in the system

 

[BenThayer]

ditto copper / brass in the system or relief.

confirm the PSV is for ammonia service. not likely an OSHA issue if on a refrigeration system but review the OSHA Ammonia standards. there is some decent info there.

http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9757

"Brass, copper, or galvanized steel pipe shall not be used."

 

[ammoniachick]

I have verified there is no brass, copper, or galvanized. Yes the valve is rated for ammonia.