refuse to fill

[rigdiver]

Not as a legitimate product.

I have yet to find the origin of the DIN for 3500 PSI rule but it seems to hold. That's why the cylinders with convertible valves are rated at 3442. Shaving those few atmospheres off of the rating gets them in under the wire.

The most common supplier of the 3500 PSI cylinders was PST and those were built with 7/8 fine thread necks. That's physically smaller than the more common 3/4 straight pipe thread. This by design or otherwise prevents re-valving to alter the configuration.

Pete

7/8 is smaller than 3/4?

Bill

 

[Scared Silly]

Yes, 3/4"NPSM is larger than 7/8" UNF because they are different standards and not direct measurement of the valves.

 

[fab50diver]

Manby regulators can be used din and yoke with no more effort than unscrewing one nut, changing out one part and screwing that nut back on. What sort of regulator(s) are you using?

I have a ScubaPro MK25-S600.

 

[rigdiver]

Yes, 3/4"NPSM is larger than 7/8" UNF because they are different standards and not direct measurement of the valves.

PSI calls it a 5/8". Order an O-ring for it.