I am hoping someone might be able to help me identify the thread on the fuel union in the pic.

Basically I need to source some with 8mm tails (I have one with 10mm and one with 6mm) but need to find out what thread they use first obviously. I think they are quite an odd size, so suggestions for sourcing 8mm tail versions welcome!

Its from a fuel swirl pot as sold by tweeks, raldes, burtons etc etc here.

The large bolt on teh right is m12, the small bolt above is 7/16unf which leads me to believe it might be 1/2unf, is this likely or a look/sound about right?
Only thing is it looks to me to have a slight taper on the thread, but I'm not sure.

I've spoken to burtons who can't tell me what size the threads are and they don't sell any alternative unions apart from the jic version of the pot.

Most unions of this size use 1/4 or 1/8npt as far as i can make out so this is a fair bit larger, maybe something commercial might fit as it has been said that this filter/swirlpot is very similar to a lorry diesel/water seperator.


thread size?

cheers,

Ned.

[Edited on 6/2/06 by ned]

Its likely to be 1/4" NPT.

http://wolfstone.halloweenhost.com/TechBase/pipthr_ThreadedPipe.html

NPT thread sizes dont match up with the actual OD of the thread, confusing as that may be...they refer to the bore of the pipe that the thread is cut on (or was originally designed to be cut on!)

David

[Edited on 6/2/06 by flak monkey]

Could always be BSP

BSP
Nom size-------- TPI -------------Major dia

1/8 ----------------28 -------------0.383
1/4 ----------------19 -------------0.518

NPT
Nom size-------TPI-------- Major dia

1/8 ------------- 27 -------- 0.405
1/4 ------------18 ---------- 0.540

Hope that makes sense

At a guess I'd say that looks like 3/8 BSPT If you measure the O/D with a micrometer and count the threads per inch I'll confirm that.

If yo buy one of These you can check it yourself.

[Edited on 6-2-06 by BKLOCO]

It looks like an air line fitting with a tapered thread.

I'd say BSPT as well.

Looks a bit like the one I had on my inlet manifold for the hot water.

PAt..

looks like 1/4 npt to me Ned. 1/4 npt is approx 1/2" midway up the taper to the thread od, which looks similar to that. It is either that or 1/8 npt which is approx 0.4" midway up the taper (all approx before the aircraft engineers shoot me down!)

Thanks for all the responses, I recon it'll be 1/4" npt as most fuel unions commonly available are 1/8 or 1/4 so I'll get a couple of straight unions,they're only £2 or so each and see if they fit.

cheers,

Ned.

quote:

---

Originally posted by trikerneil
Could always be BSP

---

You've got a branch of Pirtek in Guildford (according to their website). They're a great source of NPT, BSP and similar connectors.

If they're anything like the blokes in Ipswich you'll find them very useful... oh - and cheap, as well.

David

quote:

---

Originally posted by BKLOCO

If yo buy one of These you can check it yourself.

[Edited on 6-2-06 by BKLOCO]

---

I measured the od of the thread as a tad over 1/2" and the id as near dead on 1/4" so Im gambling on it being the 1/4npt thread

cheers again,

Ned.

BSP can be tapered or parallel

quote:

---

Originally posted by 02GF74

quote:

---

Originally posted by trikerneil
Could always be BSP

---

could be excpet BSP is not tapered.; it is clear from the picture that it is

I'd go with the npt camp.

---

Looks exactly like 1/4" BSPT Airline hose fitting to me --- try Machine Mart

1/4 BSPT --- max dia at thick end of taper 12.87 mm

[Edited on 7/2/06 by britishtrident]
Rescued attachment quartbspt.jpg

Thanks for that British Trident.
Just been on the phone to demon thieves who also sell the swirl pot and confirmed off the top of their heads that it was 1/4 npt. bits should arrive tomorrow so hopefully can confirm that they fit!

cheers all,

Ned.

Knew when you posted the question BT'd know that one!


Won't bother digging that book up.... good, as I've no idea where it is!

Cheers,
James

Just to confirm I received the new fuel union and it is a 1/4" npt thread.
thanks for all the help guys.

Ned.