Question BCD inflator hose o-ring replacement

[Pearlman]

I don't know o-ring Scuapro 138s but I found it is been used in Scuapro's first stage on high pressure piston. So I expect it to be 90shore which is definitely wrong for inflator coupling.

Does anybody know 138s' size? Might be the same size but 90shore?

Right - I just serviced my Mk25 so thats how I remembered it. It is a hard O-Ring and my intuition told me we need a softer one on the LPI. But searching for technical info to match my hunch or discover the correct size. If all universal QDs are exactly the same dimensions for the O-Ring land then safe to say it should be a 610 (as per a dive shop technicians video I saw). But thats the uncertain bit we don’t know… and mine look almost the same on both ends.

803 is much, much smaller: 6.35x1.78 I can hardly imagine this works. I expect o-ring to move around in the groove.

610 is 6.75x1.78 which still is much smaller than 611, could move around as well.

Is anybody able to measure o-ring groove? Outside diameter should be around 11mm. I am not able to measure this without distroying the coupling but I am sure a professional can do so.

My bad - you are correct! I should have stuck to the 903 (7.65 x 1.63=10.91) as the most feasible downsize from a 011 not 803. Same diameter but thinner c.s. I am wondering if it’s ok to use/compress the 011 to conform to a 903 size without encountering premature O-Ring failure? I do have to push the mini IPG stem a little hard on to the QD when inserting right now with the 011.

I think I will try the bubble test on my LPI and K-Inflator by dunking the LPI into a bucket after soaping the circumference of the connector. But in any case I will be searching for 610/903 O-rings to stock in my save-a-dive kit, a day before I dive at the end of this month.

 

[Agro]

Right - I just serviced my Mk25 so thats how I remembered it. It is a hard O-Ring and my intuition told me we need a softer one on the LPI. But searching for technical info to match my hunch or discover the correct size. If all universal QDs are exactly the same dimensions for the O-Ring land then safe to say it should be a 610 (as per a dive shop technicians video I saw). But thats the uncertain bit we don’t know… and mine look almost the same on both ends.


My bad - you are correct! I should have stuck to the 903 (7.65 x 1.63=10.91) as the most feasible downsize from a 011 not 803. Same diameter but thinner c.s. I am wondering if it’s ok to use/compress the 011 to conform to a 903 size without encountering premature O-Ring failure? I do have to push the mini IPG stem a little hard on to the QD when inserting right now with the 011.

I think I will try the bubble test on my LPI and K-Inflator by dunking the LPI into a bucket after soaping the circumference of the connector. But in any case I will be searching for 610/903 O-rings to stock in my save-a-dive kit, a day before I dive at the end of this month.

7.65x1.63 has the same INNER diamete, smaller outside diameter. This might result in a o-ring which does not fully touch housing's outside, wobbling around in the groove, which is no good at all.

Best would be to measure groove's outside diameter but I am not able to do so.

Pearlman, are you sure it is the o-ring which makes it hard to push the nipple inside the coupling? Might also be the tire valve, which is inside the coupling. Or your nipple is a bit longer? You can try to screw out the tire valve and then put nipple into coupling - of course without air pressure on it. This gives you a feeling how hard it is to overcome o-ring resistance.