SEA oring size?

[scubaalblake]

Servicing a USD SEA first stage which has a base o-ring PN 8244-07.
I know the bit about USD orings using the last 3 digits as the size - but 407 doesnt make any sense
Anyone know what size this oring should be.
Its pretty important to get the correct size as I have seent leaks from the base of the first stage in the past when the wrong size it used.
Thanks
Al

 

[knotical]

Short answer: 013, but . . .

Although some Aqualung/USD o-ring part numbers series are correlated to size, it is far from universal, and not always well aligned with AS568 dash numbers. As you've discovered, the 8244 series isn’t even close. Also consider Aqualung 8200-04 and 9570-04; they are nowhere near the same size.

I saved some of the old cards from Aqualung service kits, and in 2000 they replaced the 8244-05 with the 8244-07 for the SEA end plug o-ring. I can only guess the cause (material change?) Presumably, you could still use an 8244-05. Both are close to (are?) AS568-013. I’m sure you already know to not use just any similar sized o-ring, but to also consider material.

One useful source of information: http://www.diveriteexpress.com/hardware/orings.shtml