How to torque a hydraulic fitting

[Furu]

May be a dumb question but the only dumb question is the one that is not asked.

My question is how to torque a hydraulic fitting but the question generally is when you can't get a socket torque wrench on a bolt/nut/fitting how do you torque it to a specific setting. Using crows feet and a normal torque wrench and math I think it could be done with some degree of error due to angles changing but is there a better/simpler method. Of course one can always tighten it till it feels right but that doesn't always turn out well.

 

[RickB]

A crow's foot socket positioned 90 degrees to the beam of a torque wrench requires no math calculation. Practice will give good results; that is knowing how tight 'tight' really is. You won't get a torque wrench near many hydraulic fittings anyway. Here are fitting torque guides:

http://www.pirate4x4.com/tech/billa... Hydraulic Hose and fitting Torque values.pdf

 

[Baby Grand]

This document came in the box of my new (in 1975) SK 3/8 torque wrench:

http://www.srtorque.com/Downloads/Instructions/857313D.pdf

Hope it helps!

-Jim

 

[Monster5601]

Here is yet another resource for the math:
Torque Wrench Adapter Extended Calculation - Engineers Edge

May be a cut-a-way socket could work, like the ones used to remove oxygen sensors from the exhaust system. Doesn't seem practical though, the rigidness of the hydraulic line and diameter to nut size of the fitting would require a very long socket. Just thinking...

 

[wdchyd]

Here's a few videos that may help....

Tompkins Adapter Assembly Videos - Tompkins Industries Hydraulic Adapters And Fluid Power Products

 

[Egon]

Some type of fittings may use a criteria that involves the number of turns after finger tight snug.

 

[Soundguy]

wow.. I must be doing it all wrong.

I just put em in till they feel good and go.. and that accounts for npt, orb and jic.... I better start getting high tech and get the TW out..

soundguy

 

[Gary Fowler]

I am with SoundGuy, I have never used a torque wrench on hydraulic couplings. Just tighten till it is snug. Hydraulic fittings dont take a lot of torque to be leak tight so a bit more than snug is about all you need. If it leaks, which I have never encountered, tighten it a bit more.
If you are built like a young Arnold S. then maybe you need to torque everything, but I have found that after a few years of practice and knowing how much it takes to twist off a bolt, experience is better than torqueing. Torque wrenches dont take into consideration the friction factor and sometimes you can reach specified torque and the bolt will still be loose whereas a really well lubricated bolt may be overly tight when torqued to the max.

 

[BethesdaEC]

I have often joked that the best way to properly torque a bolt without a torque wrench is to tighten it until the head snaps off then back off a quarter turn.

 

[Soundguy]

... or to tighten till just before it breaks off..


soundguy