Selection of other instruments not related to ammonia in processes involving ammonia solution
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I have a question: In processes that involve ammonia, the use of copper is completely prohibited. The main difference between pressure gauges designed for use with ammonia and ordinary stainless steel pressure gauges lies in the welding materials used. So, must all other pressure gauges in the same workshop that are not intended for use with ammonia also be manufactured using the same welding methods as those used for ammonia pressure gauges?
Ampere gauge for ammonia is also made of 304 stainless steel, right? Can’t ordinary pressure gauges also use 304 to prevent scaling? Except for the part that connects to the pressure gauge, which is a threaded connection, the other parts can be welded.
I asked my former teacher just now; nowadays, stainless steel pressure gauges are sufficient for measuring ammonia. Previously, copper was used for the Bourdon tubes in the pressure gauges designed for ammonia, but now stainless steel is used for those purposes as well.
We’ve been using ordinary stainless steel pressure gauges for our liquid ammonia tanks for several years now, and nothing wrong has happened! It passes the inspection every six months
Mm-hmm. Since it was the first time I was working with a process involving ammonia water, I checked the relevant standard requirements more carefully and delved deeper into them; now I understand.
Welding? Welding is the same; what’s not needed is the pressure gauge itself.