OPV question

[hongrace]

Today I inflated a new OMS wing. It held the pressure ok but after 5 mins, you could feel it wasn't as ridge as the beginning. Some minor air leak was evident.

I then put the inflated wing into a tub of water and found some bubbles coming out from the OPV.

I took it open and found the following:


The yellow arrow is pointing to a fine ridge. In my other wings (which hold pressure for weeks), this ridge makes contact with the rubber pad which in turn connected to the pull-cord. The fine ridge and the rubber pad make an air-tight seal under the spring pressure.

However, in this OMS wing, the ridge is actually lower than the thicker ring (indicated by the blue arrow). Therefore, the part making contact with the rubber pad is actually this thick ring and not the fine ridge. This is confirmed by the slightly impression of the thicker ring on the rubber pad if you inspect the pad. I believe this does not create the correct sealing and hence the leak. Am I correct?

 

[cool_hardware52]

You actually want the soft seat to seal on the "thicker" inner piece. The thicker piece is the end of the inner "T-Nut" If you rely on the "Thin ridge" on the inside of the "outer nut" then gas has a chance to pass around the threads between the two pieces.

Do this:

Blow the wing up until the OPV vents.

Then pull the string a couple quick times to vent a little more gas, not a lot, just a couple quick puffs.

Now feel how taut the wing is and let it sit for an hour. If it is no less taut then you are fine.

If it is still losing gas try flipping the soft seat over in the "cup" inside the OPV.

Tobin

 

[hongrace]

Thank you Tobin.

I found this out when I tried to change the OPVs to those made by you.

So the OPVs in other wings (oxycheq) were not set correctly in the first place!!?! The impression on the rubber pads are all of the outer thin ridge of the outer nuts. The ridges in these OPVs are set higher than the thicker inner piece...

 

[cool_hardware52]

Thank you Tobin.

I found this out when I tried to change the OPVs to those made by you.

So the OPVs in other wings (oxycheq) were not set correctly in the first place!!?! The impression on the rubber pads are all of the outer thin ridge of the outer nuts. The ridges in these OPVs are set higher than the thicker inner piece...

It has been my consistent experience that using the inner T-nut to seal the soft seat is more reliable. DSS OPV's are designed to do just that.

Tobin

 

[hongrace]

have tried flipping over the soft seat in the cup. Still leaks. Do you think switching to DSS OPV will help stop the leak?

 

[cool_hardware52]

have tried flipping over the soft seat in the cup. Still leaks. Do you think switching to DSS OPV will help stop the leak?

Probably, but you will need the basic kit + the hex outer nut.

Replacing the hex outer nut requires "BC wrenches" we do not sell the wrenches, sorry. You might find these at your LDS, but many do not have them.

Tobin

 

[Splitlip]

I have 2 Oxycheq wings. I just pulled the cover off one. The inner, thicker ring is higher as Tobin describes. Maybe you need to tighten down the outer threaded part so it is lower than the inner?
Incidentally, I have the DSS Conversions. Cap, spring, string and flap only. Work great. The rest is Oxycheq.

 

[cool_hardware52]

I have 2 Oxycheq wings. I just pulled the cover off one. The inner, thicker ring is higher as Tobin describes. Maybe you need to tighten down the outer threaded part so it is lower than the inner?
Incidentally, I have the DSS Conversions. Cap, spring, string and flap only. Work great. The rest is Oxycheq.

I'd be careful about over tightening the outer nut on to the inner T nut. It's possible to break the inner T nut. Snug + a little is good.

Tobin

 

[hongrace]

The tools that required to loosen and tighten the Hex nut has arrived today and I changed the OPV to the DSS one. Water test show still leak from the OPV. After trouble-shooting, I believed the leak was not from the rubber pad and the inner ring seating. It got to be from the sealing of the inner and outer nuts. It just happened that I have a new double gasket. So I changed it and voila!! No leak!!

So my question is now, do we have to change the double-gasket when I loosen and tighten the hex nuts? The old gasket had permanent impression of the sealing rings from the nuts. If I take them out and re-assembly, chances are the gasket will find a new position and the sealing may not be perfect due to old impression. Also the DSS Hex nut has a flat base vs the ringed (ribbed) base of those from OMS or Oxycheq. So if not changing to new gasket, will there be a problem?

 

[cool_hardware52]

The tools that required to loosen and tighten the Hex nut has arrived today and I changed the OPV to the DSS one. Water test show still leak from the OPV. After trouble-shooting, I believed the leak was not from the rubber pad and the inner ring seating. It got to be from the sealing of the inner and outer nuts. It just happened that I have a new double gasket. So I changed it and voila!! No leak!!

So my question is now, do we have to change the double-gasket when I loosen and tighten the hex nuts? The old gasket had permanent impression of the sealing rings from the nuts. If I take them out and re-assembly, chances are the gasket will find a new position and the sealing may not be perfect due to old impression. Also the DSS Hex nut has a flat base vs the ringed (ribbed) base of those from OMS or Oxycheq. So if not changing to new gasket, will there be a problem?

Probably not, but you have the tools, try it and see.

Tobin