For towers using ammonia gas and ammonia water as the medium, how should the equipment flanges be selected?
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This is the content of Appendix A to HG20583. The medium in this tower is ammonia gas and ammonia water; its diameter is 1000. How should the flanges for this equipment be selected? Must a Type B flat welding flange of 2.5 MPa be selected? There isn’t this model either (up to 800)? There are also gasket rubber pads – are you referring to XB450 (asbestos rubber)?
For equipment flanges, use necked butt-welded flanges
Thank you! Then may I ask why, in this Appendix A table, there is only the Type B butt weld flange?
Ammonia is a strong permeating medium; therefore, it is better to use butt weld flanges
Thank you! Then may I ask why, in this Appendix A table, there is only the Type B butt weld flange?
In accordance with code requirement 3.2.5, for containers holding highly permeable media of moderate hazard, flanges in the range 20592–20635 should be used, along with butt-welded flanges and metal wound gaskets equipped with reinforcement rings. I recall that according to the interpretations in the old regulations, ammonia is a highly permeable medium; per 20660-2000, it is considered to pose a moderate level of hazard. It’s different now with 20583; I also want to learn* and confirm it
Just use it as a reference. Using a type B flange is less convenient than using a butt-welded flange directly
Ammonia is a strong permeating medium; it is therefore better to use butt-welded flanges for full brain development franchise
The standards apply to pipe flanges; these are equipment flanges
Yeah, I’m just curious if there are any special rules?
Then may I ask if it’s also okay to use a necked butt-weld flange with PN1.6 rating?