purging stainless pipe

[dlonu2005]

What have you used to make purging attachments for 2 inch stainless pipe. I teach at a career center and don't want to spend the money on manufactured purge parts if I can make something to teach with.

[andyhawk2003]

In the union hall foil tape is used and it does a good job, if you are talking short coupons

[Portable Welder]

Take a regulator off a machine your not using along with its hose, stick the hose in the pipe, and seal it off ( Foil tape will work ) Then cap the opposite end and put a hole in the cap about the size of your purge hose and keep it flowing while you weld.

[kvwall]

Take a regulator off a machine your not using along with its hose, stick the hose in the pipe, and seal it off ( Foil tape will work ) Then cap the opposite end and put a hole in the cap about the size of your purge hose and keep it flowing while you weld.

How many cfh is recommended?

[OldSparks]

Basically what Portable Welder said.......You can also use a splitter off one bottle with valve at end of purge hose. Set flowmeter at 30 cfh, open purge valve to flood coupon (5-10 seconds), back off purge valve to minimum flow, weld away (experiment). Should have no problem using good quality masking tape. Note...I also tape around bottom of coupon to jig before welding.

[Portable Welder]

The bigger the pipe the more cfm needed to get the carbon dioxide out, once the pipe is full of purge gas you can back it down to approx. 15-20, If its 1-1/2" pipe or less I would back it down a little more.

Purging is not something I do all the time so there may be others that can give you better advise.

Most of my purging is to evacuate explosive fumes out of a pipe or tank verses needing it for welding.