Switching from NPT to Compression Fittings

Hi All,

I’m looking to convert every single, god-damned, NPT valve, tee, elbow, plug, whatever with compression fittings from swagelok.

I’m either an idiot or these things are immensely complicated to get right without seeing them in person. I have 1/4” and 3/8” FNPT on the lid of my material column, likewise for my collection vessel.

My idea was to place an MNPT to “tube adapter”:

Then place a valve onto the protruding tube adaptor:

However, it looks like beyond that I’ll have to buy small pieces of this:

Is this sufficient for replacing my NPT stuff, or am I still missing some information?

Bonus question: anyone have sources that demonstrate the value of swagelok tube fittings to regular ol NPT?



yes and no.

that “port connector” will get you to another tube fitting…but only one within an inch of your valve.

if you stick an appropriately bent piece of 1/4" tube into the valve, the two ferules there can be compressed to give you a very similar looking seal, connected to a tube that actually goes where you need it.

you’ll need nuts, ferrules, tube, a pipe cutter or hacksaw, a bender, and at least two wrenches…a reamer to clean up the ends would be ideal.



they are SOOOOO much easier to deal with when you want to reconfigure your machine. which means your tinker toys can perform more tricks with less work.


Thanks @cyclopath, always got some insight to shed us :’)

Don’t mix the fuerrles of the Swagelok and Parker types of fittings.
They both work fine and there are decent Chinese repops at low prices but a Parker fuerrle will mess up a Swagelok fitting when really torqued.
When you make up the fittings pay attention to how far they are supposed to be torqued according to specs.
Swagelok Quick Info


You might want to consider Tri-clamp fitting instead, very easy to use, and a type of fitting that is fairly universal in the sanitary processing world. Thanks, Greg 310-212-7777

get the mnpt to swage and bend a piece of tube to get your desired direction


not in 1/4" or 3/8".

And after re-reading, I think the piece you’re actually missing @TheGratefulPhil is the compression to JIC connector to connect that swagelok valve to the ptfe/stainless hoses you have…

1 Like

Where are you located? Chrissy at Pipe Valve and Fitting Co in Denver is a good person to use for swageloc and tyloc fittings. Parker makes good stuff but their stores have a hellacious markup IMO.

I’d also ask, what issues are you having with FPT/MPT connections? I’ve personally fought leakage with some cheap import stuff because they make straight threads instead of the proper tapered threads that the pipe thread spec calls for. Also be cautious of what you are using to seal threads, some pipe dopes are better than others and some are completely incompatible with the solvents you are using.


We are a filter company and sometimes, depending on the filter housing (hardware), we do have fractional fittings and we do make them available in the 1/4" and the 1/2" TC. Typically these are vents and gauge ports. Thanks, Greg

Because you have a 1/4" NPT fitting the smallest ID you have is 1/4", therefore you’d want a 3/8" NPT to 3/8" tube fitting. 3/8" tube/compression has a OD of 3/8" and a ID of 1/4". You do not want to go from a 3/8" NPT to 1/4" tube fitting - you’re choking your flow rate.

SS-600-1-6 is a 3/8" MNPT to 3/8" Compression or a Male 3/8" NPT fitting to a 3/8" tube (female)

SS-6-TA-1-6 is a 3/8" MNPT to 3/8" tube (male). This is the larger size of the first one you showed.

Ask Swagelok to send you their bible (catalog book) its as big as a college chemistry book, is free, and is my go to when I need to correctly source fittings.


You can drill (or get pre-drilled) versions so that you can pass tubing through the fitting.

Unlike NPT they are “clock-able”.

Obtainable as tri-clamp, npt, jic adapters

Some sizes work with o-rings and PEX, available at your hardware store.

Off topic: I recommend a diaphragm between you gauge and your product. For your gauges sake…


super slick with the elbow (DIP)tube.


son of a whore!!! that looks so user friendly!!!

1 Like

Where do you get your tubing at for making runs?

1 Like

I use Paramount Supply in Eugene, but that is because I’m in Eugene :shushing_face:

I noticed titan fittings sells tube today…


I have a solid source for swagelock clones from China. I can dig up the contact if you like. Their valves are excellent functionally, they just need to be tightened with hex keys and box wrenches prior to first use because the Chinese seem to have a superstition about tightening things properly. Once that initial adjustment is complete these swage clones have lasted 5+ years with zero leakage. Forgot to mention, the 3/8" (NPT or compression fittings) only cost $10 each!


Gotta love our machine overlord’s attempt at misdirection (auto-correct)…


Thanks for the copy-edit boss :wink::call_me_hand:

I would appreciate it if you could pass that contact along if you find it.

1 Like