This adapter fits over a standard cylinder K, J or H valve and tightens onto the sealing O ring on the Yoke Insert. Please Note - The valve must be fitted with a standard G⅝ -14TPI BSP DIN to Yoke Insert.  

The adapter has two uses.

Air Top Up

Attach to a large capacity cylinder (e.g. 15 Liter (100 cuft @3,000 psi)) for use as a donor air reserve to top up receiver 0.5 or 1 liter cylinders.

This method will not completely fill a small cylinders as pressure balances out between the large donor and the small receiver. Fill top up pressure will diminish each time the process is repeated and air is consumed from the donor.

For use with an electric high pressure air pump or with a manual high pressure stirrup pump to fill a cylinder fitted with a standard K, J or H valve. 

In practice only suitable for filling small cylinders with a capacity of up to about 3 liters with an electric pump and with a capacity of up to about 1 liter with a manual pump.