Swagelock QC6 source

[joshk]

The reverse is typical. Male goes on the tank side, female on the BOV or ADV etc side.

There are non-valved QC6s. So be careful if you order direct from swagelok as the ones without valves are not very useful for diving.

That’s the nominal setup I have. But I also adapted a few female QC6s onto some Omni splitters. Because reasons.

Female side QCs should always have a shutoff. Male side you want the red sleeve (“DESO” for double end shutoff).

Has no one ordered specific fittings from Swagelok before? They all are retrofits? I’m finding that a little incredible given how widespread these fittings are. Maybe I should call my account rep and ask. I did NPT because I wasn’t sure how I wanted to move things around at the time and it gave me flexibility.

 

[tbone1004]

@joshk when I order from Swagelok I get the NPT's and have my machinists cut them down for me. I haven't bothered to ask if they can give a solid end block so I can custom mill them, but that may be where I go for the next attempt. Let me know what you find!

 

[joshk]

@joshk when I order from Swagelok I get the NPT's and have my machinists cut them down for me. I haven't bothered to ask if they can give a solid end block so I can custom mill them, but that may be where I go for the next attempt. Let me know what you find!

What NPT size do you order?

I was going to ask them to tap/thread them directly, not a plain end. I think they offer “plain” as a stainless tube fitting which you can put any Swagelok connector on. Though I don’t know if they have tube to 3/8 or 9/16.

While we’re on the topic of fittings and adapters, why are scuba fittings these sizes? Is there any historical reason? I’ve been wondering about some hose fittings. I could order a few SKUs off McMaster but it’d save time if I knew what I was looking for.

 

[tbone1004]

What NPT size do you order?

I was going to ask them to tap/thread them directly, not a plain end. I think they offer “plain” as a stainless tube fitting which you can put any Swagelok connector on. Though I don’t know if they have tube to 3/8 or 9/16.

While we’re on the topic of fittings and adapters, why are scuba fittings these sizes? Is there any historical reason? I’ve been wondering about some hose fittings. I could order a few SKUs off McMaster but it’d save time if I knew what I was looking for.

I'll have to check my order, it's been a few years and I don't remember.

No idea about the specific history, but like most things it has to do with what was readily available at the time and was physically the right size to not make the regulators massive.

 

[rjack321]

Has no one ordered specific fittings from Swagelok before? They all are retrofits? I’m finding that a little incredible given how widespread these fittings are. Maybe I should call my account rep and ask. I did NPT because I wasn’t sure how I wanted to move things around at the time and it gave me flexibility.

@nadwidny has ordered from Swagelok directly. But he had a business account at the time.

I guess I am wondering why you would bother? They are not substantively cheaper.

 

[joshk]

@nadwidny has ordered from Swagelok directly. But he had a business account at the time.

I guess I am wondering why you would bother? They are not substantively cheaper.

Ordered QC6 fittings with 3/8 or 9/16? Or ordered ¼” NPT and wrenched an adapter on it?

Getting ¼” NPT direct from Swagelok was substantially faster and easier to deal with than most scuba places I looked for fittings. It also allowed me to build my own connections as needed.

The advantage I see of getting 3/8” female (on a female QC6) or 9/16” male (on a male DESO QC6) is that the fitting itself is smaller. QC6s are large. I could cut at least ½” of length on either side (1” total) and possibly more by having the correct connection on there to begin with. The cost is less of an objective.

 

[rjack321]

Ordered QC6 fittings with 3/8 or 9/16? Or ordered ¼” NPT and wrenched an adapter on it?

Getting ¼” NPT direct from Swagelok was substantially faster and easier to deal with than most scuba places I looked for fittings. It also allowed me to build my own connections as needed.

The advantage I see of getting 3/8” female (on a female QC6) or 9/16” male (on a male DESO QC6) is that the fitting itself is smaller. QC6s are large. I could cut at least ½” of length on either side (1” total) and possibly more by having the correct connection on there to begin with. The cost is less of an objective.

Light monkey carries exactly what you are doing in a smaller & lighter package.
QC-6 Connectors (lightmonkey.us)

If the female side is going to a manifold you won't need any NPT to scuba adapters at all. If the female side is going to a BOV you will need an adapter one way or another.

SS NPT fittings are good for "one" and pretty much only one attachment to whatever. If you connect and disconnect them more than once or twice they will gall and your fitting is ruined. So don't think you can mix match and change your mind on these 1/4" NPT adapter to QC6 variations. You get one, maybe two, tries.

 

[joshk]

Light monkey carries exactly what you are doing in a smaller & lighter package.
QC-6 Connectors (lightmonkey.us)

If the female side is going to a manifold you won't need any NPT to scuba adapters at all. If the female side is going to a BOV you will need an adapter one way or another.

SS NPT fittings are good for "one" and pretty much only one attachment to whatever. If you connect and disconnect them more than once or twice they will gall and your fitting is ruined. So don't think you can mix match and change your mind on these 1/4" NPT adapter to QC6 variations. You get one, maybe two, tries.

$200/pair feels steep. At that price I'd like it to come out of the box with a 3/8" female so the BOV connection doesn't need yet-another-adapter. I do NPT + Adapter already.

 

[nadwidny]

@nadwidny has ordered from Swagelok directly. But he had a business account at the time.r.

I've also ordered from the local Swagelok guy before I had my business. In my neck of the woods they are pretty much just a franchise and won't turn any business away.

 

[tbone1004]

for reference, directly from Swagelok each side is about $50. You're paying 100% markup for the machining. Your call on whether it's worth it or not.