Purge Plugs

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I just got done welding a bunch of sanitary coupons and 2" sch 40 ss 6g coupons for a project my employer is trying to keep from another contractor that is trying to move in on our work. After 3 days of cussing tape I started looking into a set of purge plugs.  But since I like to try and build something before I buy it, im wondering if there is anyone with any tips, tricks, or has on the part, make a set of purge plugs.  Preferably a set that you can slide inside a length of pipe and only purge a small 6-8" section around the weld.  And be able to handle the heat.
Reply:If I were to make it, I would try to use that cording they use on wood furnaces. For the distance away from the weldment your purge section should be installed, I would think it could handle the heat. Use that as a gasket around the plug sections, like an o-ring. That, or even something like mesh steel wool twisted into "strings" to form a seal would work. It would give you enough "leakdown" too to push the air out.Just a thought.
Reply:Thanks for the reply, what do you mean by "cording used on wood furnace"  I've always had electric heat.  Lol
Reply:It's the door gasket material for a wood stove - different styles available.Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Ok, that makes sense.  Ideas for a collapsible plug that could be fished in/out of the pipe?  The plumbers use test balls that can be inflated but there is no way they would handle anything close to the heat that would be needed
Reply:How about a multi segment disk like a tailpipe expander with a slot on the outer rim for the high temp cord?Overly complicated maybe, but would work Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:Right. So thinking along those lines, you could affix a diaphragm of some sort to a cylinder hone.  One of them spring loaded 3 finger  jammies.
Reply:its possible you can integrate those purge divider disks that stop your purge from going past them that dissolve with water when you use the pipe. Really though, those purge plugs etc. that are professionally made are real nice. I don't know how much your looking at price wise, but they may be hard to build something quality like that.Note: I have no personal experience using purge plugs. Just seen them.   Also, Your wife sow? buy some nylon or other material to be sown into the bags. Just an idea.Dynasty 200DX   (2014)Millermatic 211 (2015)Optrel 864   (2014)Smith Medium duty MBA 30510 (Xmas 2014)Tennsmith 16ga 4ft finger brake (2015)Trailblazer 325 EFI and excel Thermal dynamics Cutmaster 82Miller maxtron 450
Reply:Well I found these http://www.purgeplugs.com/order/#!/P...sort=priceDesc which is pretty slick, and kinda what I've been basing this idea off of.  They are $225 for the set which honestly isn't too bad, but if I can fashion something similar at a much better cost, then im all about it.  The material and craftsmanship does not have to match, just the intended function. Attached Images
Reply:Sounds cheap as hell, but you almost could fashion a small section of copper/whatever pipe, and cap both ends. Use a drill and drill many small holes in the center of the pipe section. Then attach a nipple on the end, and drop it down the pipe. Make sure the pipe is a little bit smaller than the inner diameter of the pipe to be welded. Then position it so it is at the weld joint, then fire up the argon. The argon dumps into the copper pipe, and blows out of the unit onto the backside of the weld joint. Its not a perfect idea, but for the 10-20 you may have in the pipe and fitting (given this job isnt on 12" diameter material) its worth a shot.
Reply:That could actually be really simple.  Im picturing something that looks kinda like a pill with a bunch of small holes in the middle.  I sees that working rather well until there is a 90° or 45°.  Altho one could probably reduce down from the caps and use 3/4 or 1/2 soft copper and probably make it around some of the elbows
Reply:I have had the purge plug set for five years. Spend $400 and get everything they have the purge plug back plate, and the purge tee.  I have had two other purge setups one from tri-clover and one from westfallia-surge meltec.   Don't try to reinvent the wheel the people at purge plugs have.  If you are want to get into sanitary welding spend the money on good equipment. A good pipe and tubing cutter like the Exact PipeCut 170E system that will make a sq cut on pipe or tube from .6" to 6.7".  And the Metabo rbe 12-180 pipe belt sander.  Fit and finish of the product is what you want. I bought both of the above items within the last year and they are time savers after all time is money
Reply:Well the thing is, it's the company I work for.  They have done little bits of food grade in the past but not much.  There is a big 2yr project I think they got that is all SS.  Some food grade, some sch40.  They have some of the equipment and whatever they dont have, I get the feeling we will have to try and do without.  I can't stand that ****, but it's completely out of my hands, and other than **** like that, they treat me good so I won't go anywhere.That being said, I try to only carry tools that would make MY job easier.  Purge plugs would definitely be nice to keep in my bucket, I just hate to have something of value that everyone else will want too.  If that makes sense, that is why I try and get by with cheap first.
Reply:i saw this thread the other day and thought about this method but was too lazy to take a pic till now. this home made contraption was taken from a book published in the 40's. the cones slide along the hollow center tube till they are tight to pipe ends and purging gas is introduced through the center tubing. if you look close you can see the gas fitting at the far left. sorry about the bad pic quality. Attached Imagesi.u.o.e. # 15queens, ny and sunny fla
Reply:Like a giant set of 2 hole pins.  I c. I c
Reply:For $400 if I were you I would buy the purge plugs for myself and it would be like any hand tool, you let nobody else use them without you direct supervision they are yours.  People working for me have to provide there own hand tools and a battery powered tools they take care of their own stuff unlike provided equipment.
Reply:Originally Posted by Milkerman  People working for me have to provide there own hand tools and a battery powered tools they take care of their own stuff unlike provided equipment.
Reply:A Water Soluble Purge Fiim     http://www.huntingdonfusion.com/inde.../article?id=88            http://www.huntingdonfusion.com/inde.../article?id=88TO INVENT  YOU NEED A GOOD IMAGINATION  AND A  PILE OF JUNK'' - THOMAS EDISONMost Of The Time People Don't see The Quality of a Good Job Unitl they see a Bad Job !! -Scott Esplin
Reply:The back purge plate is used for ferrules at the end of pipes it is used with the plug with the diffuser  on and keeps the plug away from the weld area and only purges a small area it also locks the ferrule tight to the pipe.  The only part that I don't have is the purge tee which is very useful for welding elbows tees.  This is the best purge kit of the three that I have owned.  I also run 30cfh of purge as that supports the weld and leaves a very clean inside as Skull 1 said.  $400 for everything is cheap the plugs will take some heat without melting unlike the meltec and tri-clover.
Reply:Originally Posted by Milkerman  I also run 30cfh of purge as that supports the weld and leaves a very clean inside as Skull 1 said.