US Divers K Valve Oring Question

[BigRed96]

Good Evening All, I rebuilding a vintage US Divers K Valve and have stubbled upon an issue. There is a plug on the right hand side of the valve and I’m trying to figure out the oring size for it. I have included a pic of a valve that’s the same as mine.

 

[Couv]

Assuming it's not the blow out plug, I believe that plug was for an SPG. Remove the plug and check the size. If 3/8" use a -011. If 7/16" use a -012. As there is high pressure differential there, suggest a duro 85-90.

 

[BigRed96]

Assuming it's not the blow out plug, I believe that plug was for an SPG. Remove the plug and check the size. If 3/8" use a -011. If 7/16" use a -012. As there is high pressure differential there, suggest a duro 85-90.

Thank You Sir. The blow out plug is on the back side. I replaced it with a multi-directional burst disk plug.