Fuel tank union: thread type

[boggie]

Hi all,

 

I am resoring the tank on our post-TS60000 TR3a. I have POR15 flushed, degreased and metal prepped the tank inside ready for the liner/sealer unce it is all dry. I want to clean up the union threads on the outlet and breather but am struggling to identify thread type so I can get the right tap and die set so need some help please...

 

The diameter of the male connector is 0.51" and measuring between the peaks across 4 threads is 0.16". All this seems to suggest is a 1/2" 18tpi thread but this is an odd size. The only listing i can find is for a 1/2"UNS.

 

Does anyone know for sure what size the tank unions are please?

 

Thanks,

Ian

[Lebro]

¼" BSP is 0.518 O/D & 19 TPI.

 

Your measurement across 4 peaks is 3 threads so 18.75 TPI

If 19 TPI then measurement across 4 peaks would be 0.15789"

 

Bob.

[boggie]

Ah, I had counted the thread at the start of the inch too....

Allowing for the slight inaccuracies in only being able to measure across 4 threads it sounds like I might need to get a set of BSP taps and dies...

 

Does anyone know for sure if this is correct for the tank unions please?

[BlueTR3A-5EKT]

I have been fitting the elbow and pipe from the TR4-6 (149556) in the tank. - I have a couple of NOS of the tube nuts with both 1/4 & 5/16 pipes and olives fitted.

PM me if you want one posted to UK for £5.00

 

 

It is 1/2" x 20 UNF threaded. - It fits tank and pump.

 

Peter W

Edited May 10, 2017 by BlueTR3A-5EKT

[boggie]

Interesting, thanks Peter.

I have a comprehensive set of UNC/UNF taps and dies but mothing seemed to match and none of the thread gauges matched. I will check again and make sure I try a 1/2"UNF20.