Eng-Tips is the largest engineering community on the Internet
Intelligent Work Forums for Engineering Professionals
-
Congratulations waross on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!
AMMONIA LINE
- Thread starter purnawan
- Start date
Hi Purnawan
In general for high pressure system or piping containing hazardous material, anything above 2 inches should be butt welded. For 4" & 6" ammonia line I would say must be butt welded.
Then you should gamma-ray test it for welding quality before you pressure test it with water of low chloride content (assuming you are using stainless steel pipe for ammonia)to up to one and a half times working pressure.
This is a general procedure without knowing full details of your situation. You should check ASME B31.3 for chemical plant piping.
Paul
In general for high pressure system or piping containing hazardous material, anything above 2 inches should be butt welded. For 4" & 6" ammonia line I would say must be butt welded.
Then you should gamma-ray test it for welding quality before you pressure test it with water of low chloride content (assuming you are using stainless steel pipe for ammonia)to up to one and a half times working pressure.
This is a general procedure without knowing full details of your situation. You should check ASME B31.3 for chemical plant piping.
Paul
AMSE B31.3 should only be used if the line is totally conatained within the boundaries of of single plant. If the line is cross-country and/or crosses public lands or roads, then the provisions of ASME B31.8 and CFR Part 192 will apply.
But I agree that any line over 2" should be butt-welded.
But I agree that any line over 2" should be butt-welded.
Ammonia piping typically falls under ASME B31.5, and is normally carbon steel. A53F pipe (usually junk to be avoided anyway), however, is expressly prohibited.
If for no other reason, economics dictates butt welds in larger diamter pipe. 2" pipe is the typical upper threshold for socket welding.
Many plants (most of my experience involves food processing operations) avoid hydrostatic testing of ammonia systems, and use pneumatic. This is because even trace amounts of moisture in these systems will cause operational problems due to ice crystals forming.
If for no other reason, economics dictates butt welds in larger diamter pipe. 2" pipe is the typical upper threshold for socket welding.
Many plants (most of my experience involves food processing operations) avoid hydrostatic testing of ammonia systems, and use pneumatic. This is because even trace amounts of moisture in these systems will cause operational problems due to ice crystals forming.
purnawan,
Go with the experience of the ammonina manufacturers and distributers.
Most of what is said above is valid,... however check the following website and ask LaRoche specific questions about your storage/transfer systems
ASME B31.3 is the appropriate piping code; butt welded fitting are best above 2"NPS.....avoid water in piping systems.
let us know what you decide..........
MJC
Go with the experience of the ammonina manufacturers and distributers.
Most of what is said above is valid,... however check the following website and ask LaRoche specific questions about your storage/transfer systems
ASME B31.3 is the appropriate piping code; butt welded fitting are best above 2"NPS.....avoid water in piping systems.
let us know what you decide..........
MJC
MJC - Applicable code depends upon the jurisdiction and plant. In Ontario, unless the NH3 piping is in a petro-chem, pulp & paper mill, etc, it very much WILL be deemed to fall under ASME B31.5. Always check with the local inspection authority.
- Status
Similar threads
- Locked
- Question
- Locked
- Question