How Easy Is It To UNweld????

[ScubaSteve]

So I recently got this tri-clover fitting that has a flange welded OVER it. It is a 1/2" size triclover with a 3/5" flange welded to the back of it. You can see it from the back:

And the front:

The factory it was used at must've bolted the large flange to a bulkhead or something. There is a ring of residue where it looks like a gasket used to live. It looks like there is room on the face of the big flange to place a gasket over and around the 1/2" triclover (the OD is 1", I could use a 1.5" gasket) but I wouldn't know how to clamp another fitting against the big flange. Buying the same flange to match up the other side could be pretty $$$. Does this make sense?

I wonder if I can cut off the big flange? Or, could I heat the thing and loosen the weld? It's a pretty thick piece of SS, which is a TOUGH metal. I'm just a regular guy, I don't have a plasma cutter or MAPP torch. I just have propane, an angle grinder, a jigsaw, and a reciprocating saw. (But losing a finger isn't in my 5 year plan.) If I could get the big flange off, then I could just use the tri-clover as it was intended.

Any suggestions?

 

[bad coffee]

scrap it.

Welding isn't like soldering. Welding something actually makes it one solid piece. Solder just fills the gaps between two pieces. You don't re-heat a weld to break it, you cut and/or grind it. You'll have to cut off the flange, and re-grind the fitting.

Other than that it's pretty useless as a stand-alone fitting. You could buy a gasket or make one out of a silicone baking sheet if you have something to bolt it to. What's the other end look like?

B

 

[brewmonk]

+1 above

short answer = "*NO*!"

(what's it attached to? a pump? cut the flange OFF, use the pump)

 

[leboeuf]

You can "unweld" with a saw or a grinder

 

[thantos]

Ok, so what you have there is a 1/2" Zero Static Diaphragm valve with a 1/4" sample port most likely it is 316L SS that has been electropolished to 20ra finish or better. Its probably at least 10+ years old as all newer valves are of the block valve configuration. These are mainly used in the Bio Tech industry because of the 100% drain ability and sanitary use applications. That valve you have is/was probably a $500.00 + dollar valve! I would not throw it away!

The only thing that would make it better is if it had the PTFE Diaphragm instead of the EPDM. It is good to well over boiling temps and is pressure rated to 150psi. Cut the flange off and take it to a shop and have a tri clamp sanitary ferrule welded on or get a Swagelok coupling to join the two together and use it for what ever you need! Diaphragm valves are far superior to ball valves, I use them on all my brewing equipment, you wont realize it until you have taken apart a ball valve and seen just how much crap gets left in the seats. Worse case throw it on ebay and make some money! Here is a link to the style of valves I use so you can bone up on them, hope this helps.

http://www.ittpureflo.com/

 

[bad coffee]

blah blah blah. That valve you have is/was probably a $500.00 + dollar valve! I would not throw it away! blah blah blah

EBAY THAT SHTI and buy half a new rig with it!

B

 

[sanch]

I was thinking CHAIN SAW and THERMITE but e bay would also work, although not near as entertaining.

 

[mordantly]

hack saw, band saw, sander, grinder, or milling machine.

 

[ausdb]

Sorry disregard this post Thantos has already suggested this

Why not just cut it off at the back of the flange and get someone to weld a new triclover ferrule onto the pipe stub? By the looks of it there is more than enough pipe left coming off the body of the valve.

 

[bad coffee]

I was thinking CHAIN SAW and THERMITE but e bay would also work, although not near as entertaining.

why would you waste thermite on anything that small?

B

 

[ScubaSteve]

Yeah, these are Gemu diaphragm valves. They're pretty good, but like Thantos said, it would be better if they were the updated version. They're pretty stout, and sanitary to boot. Plus, that tee configuration with a drain/sample valve is just what I need in my rig. The only problem is, they're different than all the other valves I'm using in my rig! I'm trying to get a bunch of swagelok valves with the black handles cobbled together. Aesthetically, it's not a very good fit. Plus, I'm not sure what I'd be getting myself into by paying a welder. If I take a hacksaw to it and use a swagelok adapter, I'm not sure if it would attach to a pipe with this wall thickness, as they are designed for tubing. Plus wouldn't that further restrict the ID? The ID of a 1/2" triclover line is 3/8"...if I add a tubing adapter, it will surely put more hardware in the tube (heh, heh )? Iplan on using this as my water inlet for flushing, filling, and chill water through the CFC. Flow is important, even though it should be at pretty high pressure coming from a city supply.

What do you guys think? I was thinking about going perpendicular to the back of the flange with a hacksaw....hopefully the weld is just around the pipe and not also to the back of the triclover. If I can hack through the big flange, it should fall away once I reach the gap between the big flange and triclover flange.