Cutting PVC Fittings

[john.m.cole3]

I'm using an external beckett style skimmer for my current build. I'm using a threaded fitting to slip from the skimmer output, then a union, followed by another threaded fitting into the bulkhead in the sump. The 2 threaded to slip fittings are taking up so much space in my stand that the skimmer won't fit in there well, but it will fit with 0 millimeters of extra space. I was hopoing I could cut about a quarter of an inch off each threaded fitting by the slip end. Has anyone ever done this successfully?

 

[iemsparticus]

I'm using an external beckett style skimmer for my current build. I'm using a threaded fitting to slip from the skimmer output, then a union, followed by another threaded fitting into the bulkhead in the sump. The 2 threaded to slip fittings are taking up so much space in my stand that the skimmer won't fit in there well, but it will fit with 0 millimeters of extra space. I was hopoing I could cut about a quarter of an inch off each threaded fitting by the slip end. Has anyone ever done this successfully?

I've never actually done it, but I don't see why it wouldn't work. That would still leave a decent amount of pvc to fit into the joining pipe, even being shorter.

 

[jhoop]

Use a " DeWalt" chop saw. Cuts nice and straight.

 

[justingraham]

So are u saying to cut the treads or cut the slip side? Is there any way u could just use a union instead? It's not under a lot of pressure either so u wouldn't have to glue it on the one side just the side coming from the bulkhead

 

[cromag27]

I would not cut any of the threads.

 

[john.m.cole3]

I want to cut the slip side by about a quarter inch on 2 fittings that attach to a union

 

[cromag27]

If it's the pvc pipe, I don't see why not. don't cut the actual fitting though. they're specifically tapered.

 

[john.m.cole3]

it was the fittings that I wanted to trim down. What do you mean they are tapered? Like they start bigger at the opening of the fitting and slightly narrow towards te center of the fitting?

 

[cromag27]

Correct.

 

[Sleepydoc]

Yes, this will work for slip fittings. I have trimmed about ⅓ of the depth off of some elbows I used for my coast to coast overflow. As always, check the fit before you glue, but it should work fine.

Threaded fittings are another story, as NPT fittings are tapered, so if you cut the end off you will cut the widest part of the female fitting or the narrowest part of the male fitting and make it more difficult to fit the two together. (There's a picture towards the bottom of the wikipedia article on NPT fittings that may make it clearer)

I can't quite picture you're connections, but they do make threaded unions, so it sounds like you could save space by connecting a threaded union directly to your skimmer connection.

 

[john.m.cole3]

Yes, this will work for slip fittings. I have trimmed about ⅓ of the depth off of some elbows I used for my coast to coast overflow. As always, check the fit before you glue, but it should work fine.

Threaded fittings are another story, as NPT fittings are tapered, so if you cut the end off you will cut the widest part of the female fitting or the narrowest part of the male fitting and make it more difficult to fit the two together. (There's a picture towards the bottom of the wikipedia article on NPT fittings that may make it clearer)

I can't quite picture you're connections, but they do make threaded unions, so it sounds like you could save space by connecting a threaded union directly to your skimmer connection.

Yeah a dual threaded male NPT union would solve my issues

 

[Sleepydoc]

Yeah a dual threaded male NOT union would solve my issues

You mean like a PVC nipple?

 

[john.m.cole3]

No I could use a union with male threaded in each end

 

[Sleepydoc]

Aha. never seen a MPT union. Google didn't turn up much either, so I suspect they either don't exist or are quite rare if the do.

Your original post said "threaded fitting to slip from the skimmer output, then a union, followed by another threaded fitting into the bulkhead in the sump." Can you swap the threaded bulkhead in the sump out for a slip bulkhead? That would let you eliminate the slip-MPT adapter and save a bit of space.

 

[john.m.cole3]

I figured it out! I wanted all the fittings on this build to be threaded so that things could be removed and modified later down the road if need be. After talking with a fb friend she recommended using a regular threaded union with "nipples"

this will save me the most space. BRS has them

 

[Sleepydoc]

Isn't that what I suggested above? :rolleyes:

Glad you found something that will work!

 

[john.m.cole3]

You mean like a PVC nipple?

OMG I missed that! The answer was in front of me all along. Thank you for your help!

 

[cromag27]

Just don't use thread seal tape.

 

[john.m.cole3]

Just don't use thread seal tape.

Of course. I use the LA Co pvc thread sealant stick

 

[Sleepydoc]

Just don't use thread seal tape.

Yes - good advice. Non-hardening thread sealant is much better for threaded fittings - Seals better, more reliable, and less chance of over tightening and cracking fittings. I've used this in the past with good luck, but there are other options available.