Galvanized pipe brazing
Galvanized pipe brazing
(OP)
Anyone has experience in brazing of galvanized pipe in fire system piping?
I'm interesting how this joint working during water hammer?
I'm interesting how this joint working during water hammer?





RE: Galvanized pipe brazing
RE: Galvanized pipe brazing
Brazing of Galvanized steel presents a few problems that are detrimental to pressurized applications. These joints can catastrophically fail resulting the in loss of life and property.
The brazing temperature approaches the melting point of the galvanizing. Depending on the galvanizing alloy the melting temperature may be as low as 830F. Brazing, oxy-fuel or inert gas torch brazing, being a relatively slow process, allows a significant amount of time for elements in the galvanizing alloy to migrate into the steel. This leads to Liquid Metal Embittlement of the steel. Galvanized chimney flue liners typically fail in the manner, numerous house fires have been reported due to this.
Brazing pipe together is highly depended on fit-up. Galvanize coating is not an exact science, the thickness can easily vary 0.3 mm. This results in poor wetting of the joint, during brazing.
Welds typically have porosity problems due to the volatility of zinc at welding temperature. Cracking is also a problem.
Either Welding or brazing may result in a failure with or without water hammering occuring.
RE: Galvanized pipe brazing
RE: Galvanized pipe brazing
RE: Galvanized pipe brazing