Bump Tube Form Standard 1

[jnelson33]

Hello All,

We're finding it difficult to source the specification for what the aftermarket is calling a bump tube fitting.

This fitting was popular on USDM brands for several decades and might still be used on some legacy vehicles like Ford's E-Series vans.

Regardless, the best I can research is that it could be a push connect fitting, or bump tube. Bump tube is by far the most popular name in the zeitgeist.

Here are some pictures.

• This one shows the standard tube form with sliding nut: An O-ring typically installs on the tube and sits adjacent to the flange formed in the tube. Note the slight flare on the tube's end.

• This one shows an aluminum adapter fitting that also has the flared style tube.

• This one shows a straight form instead of a small flare.

Any help is appreciated: Thanks in advance!

 

[CapriRacer]

I would call those flared fittings and I think there are SAE standards on them.

Here's what Wikipedia says: "The most common flare fitting standards in use today are the 45° SAE flare[2] [3],the 37° JIC flare, and the 37° AN flare.

So SAE, JIC, and AN standards.

 

[3DDave]

I think those are not flared fittings because flared fittings don't use an o-ring in that manner.

See https://www.atcoproductsinc.com/wp-content/uploads/ATCO_EG-1031-Hose-and-Fitting-Guide.pdf

Atco also references:

IMACA 305 - Section 7 seems to depict the tube configuration that matches.

https://www.macsw.org/images/Macs_Docs/Membership/IMACAStandard305.pdf

Check with the IMACA for the latest version of their standards if that is important. Note that section 7 says they do not control any self-retaining dimensions for o-rings which the slight flare appears to be for in the first photo.

 

[jnelson33]

Thanks for sharing that info; would have never guessed mobile air-con standards. That allows us to be certain about the O-ring versus tube diameter when designing this billet adapter fitting.

 

[Doug Hunter]

Try these guys if you are still in need:

Aeroquip

aeroquipperformance.danfoss.com