We should clarify what dead pressure gauges are for this issue. The spring tubes of ordinary pressure gauges are mostly made of copper alloy (alloy steel is used for high-pressure gauges), while the spring tubes of ammonia pressure gauges are made of carbon steel (or stainless steel), and copper alloy is not allowed. Because ammonia reacts chemically with copper and can explode, ordinary pressure gauges cannot be used for ammonia pressure measurement.
There are many materials used for pressure gauge interfaces, but besides stainless steel, some pressure gauge interfaces also use copper alloys, mainly bronze (copper tin alloy), brass (copper zinc alloy), and white copper (copper nickel alloy).
So a sealing gasket must be added at the joint of the pressure gauge.
There are many types of RTJ gaskets, including R Gasket,RX Gasket,BX Gasket, SBX Gasket,IX Gasket,and various customized products.We will do more sharing about ring joint gasket.