Hydraulic Fittings Confusion (2024)

I found some information at surplus center which now has me confused regarding the fittings I need to use for my log splitter project. So here are some questions about hydraulic fittings.

1. whats the difference between NPT & NPTF ?
2. the surplus center information said the best connection should be with SAE o-ring not with NPT.
3. can you get cylinders and valves with SAE o-ring ports ? I only see them with NPT or NPTF ports.
4. does everyone just convert at the connector NPT to SAE and then back again ? this doesn't make sense.
5. what do you guys do ?

I can go on and on with the stupid questions in my novice lay person knowledge of the subject matter so I will stop as I think you all understand my confusion by now.

Please help.

Thanks,
-unixkid

Here's a BIG start -

http://www.discounthydraulichose.com/v/vspfiles/downloadables/thread_guide.pdf

NPT is National Pipe Tapered - NPTF is National Pipe Tapered Fuel - compatible enough to interchange, but needs sealant or it will leak.

SAE O-ring, aka ORB, are much better than NPT - with a 90 deg. fitting, you can point it whatever direction you want and THEN tighten the lock nut which pushes against a flat washer which pushes against the O-ring which makes a leak proof seal pointed the direction you need it. Try that with NPT, it'll almost never point where you want it and seal.

Some cylinders come with SAE/ORB fittings, some with BSPP (British Standard Parallel Pipe), some with NPT, some may even come with JIC 37 deg. fittings. Last two I bought, one was BSPP with an included adapter to ORB, other was NPTF and I'll add NPTF to JIC straights and JIC male/female elbows so I can point them where I need them.

Same place as the above thread chart DiscountHydraulicHose.com also has tubing compression fittings that will adapt to JIC, etc - check out their site, there's lots of pix but not a lot of "schooling" - Surplus Center's tech section seems to have more of that.

Also -

Technical Frequently Asked Questions

http://www.derijcke.com/dl/manual.pdf

http://www.phtruck.com/download/training/trainingbasichydraulics.pdf

Those should get you started - I've spent about two days just looking thru discount's site and sussing out what things were, and still messed up my parts order til JJ filled me in on WHY I couldn't do what I intended initially -

So read, look, scratch yer head, ask questions, somebody'll chime in and eventually you'll be helping others with your newfound ejamicashun ... Steve

for those of you NPT haters.. they do make swivels with a sealing shoulder.. so once you get the taper section secured and not leaking int he parent material.. then you can tighten the swivel yo your hose and go.

some of us old tractor owners had to get good at this instead of waiting fo rthe new tch to get here and do the work for us..

ArkanDan said:

Not exactly on topic here, but I see a link to "discounthydraulichose.com" and thought it might help someone out who's dealing with a hydraulic problem or doing some down home fabricating. I got an e-mail from them yesterday stating that if anyone places an order between now ant the 10th of December that they can get a 15% discount by typing in the word HOLIDAY in the coupon section. Not a big window of opportunity, but a pretty good deal for anyone that is ready to order. Came a couple days too late for me.

Click to expand...

I just ordered some fittings from them and everything came in good order etc. I had 3 day select as my shipping method and they called to let me know I would have it in 2 days going with ground......so kudos to them!

Yeah, I got that 15% email shortly after posting - too short a window for me too, I'm nowhere near knowing what all I'll need for all the mods I'm looking at for the Case, still working on the Allis. Maybe next time...

Speaking of wierd ports, just checked this cylinder out. Note the DIFFERENT push and pull ports. Huh???!?

https://www.surpluscenter.com/item.asp?item=9-7850&catname=hydraulic

There's a couple like that. New to me... Steve

Thanks to all who answered. Good stuff.

Much appreciated.

-unixkid