SAE 8 orange boss leaks

[Bsavulis]

I have a diverted valve with 6 oring boss fittings. The orings fail frequently. I am not sure if it is poor installation or bad sealing surfaces, or something else. The oring will be pushed out in a small area around the fitting. When I install new orings I put them as tight as possible but they still eventually leak. The valve just has a flat surface for sealing. There is no counter bore. Should I try a copper ring instead? The valve and fittings are a chore to access so I would like to solve this. The orings hold for a while but then start to drip. Not all at the same time. Just one or two. System pressure is set for 2200psi.

Thanks
Brian

 

[K5lwq]

You may be over tightening them. ORB normally does not take much to get a good seal.

 

[LD1]

ORB should have a small counterbore for the oring to seat into. It's very subtle....but I bet it's there. Almost looks just like using a countersink to knock the edge off the hole.

Is this ALL of the fittings on the valve that are causing issues....or just one? Maybe if just one.....the bore has a burr or something cutting the o-rings.

Also....ORB o-rings are different than your standard o-rings. So are you just finding something that looks like it will work out if a generic oring kit? Or are you actually getting ORB o-rings? They are slightly different sizes....and a bit harder durometer.

Pictures would be worth 1000 words here

 

[Zebrafive]

It could be any of the above posted answers.
I am think:
You are tightening too tight, for -8 or 1/2" the torque is 34lb ft.
Wrong O-ring
Poor machining of the part the fitting mounts to.
In that order.

 

[oldnslo]

From your description it sounds like you have BSPP ports which require a seal ring. BSPP seal on the surface while SAE have a chamfer the O-ring fits into

 

[LD1]

From your description it sounds like you have BSPP ports which require a seal ring. BSPP seal on the surface while SAE have a chamfer the O-ring fits into

I didn't think BSPP threads were the same as SAE. But I don't deal with BSPP at all. Maybe just close enought to think they are right?

 

[ptsg]

BSPP adjustable swivel fittings will have an O-ring which can easily be confused with an ORF fitting.

My experience with Korean manufacturers is that they do use BSPP fittings on their tractors.

The idea of these fittings is to thread the fitting as much as possible without bottoming it out on the nut and till it points the right direction. The just tighten the nut. No need to go crazy on the torque either.

Here is a picture of one of these fittings for reference:

 

[oldnslo]

LD1
I would have to dig out my thread chart to confirm but I think a couple of the BSPP are close enough that SAE will fit I believe biggest difference is 1 threads per inch difference same as I have seen NPT screwed into SAE ports.

 

[TractorGuy]

I'm betting you have the wrong o-rings. Go to your local hydraulic shop and get the right ones or order from one of the online suppliers. My diverter also has the #8 SAE ports and I haven't had a single o-ring fail.

 

[07keo02]

If the o-ring is squeezing out and showing then either:

1: There is no counter-bore and in this case the port is not ORB.

2: There is insufficient shoulder on the fitting. This could happen in a swivel 90 where the nut/washer was removed and the o-ring was installed against the hex portion of the fitting. Same thing happens when using a Jic fitting in an ORB port without an o-ring backing washer.

3: Wrong o-rings.

Otherwise, the o-rings should not show once the fitting is seated.