Timer release or shutoff on nitrogen gas cylinder, possible but where to buy?

[dave diamond]

Is there such a thing as a cut off valve with correct cga-580 (I think) gas fitting for a nitrogen cylinder? If so where can I buy it in the UK? Thanks.

 

[dave diamond]

Bump. Where can I get a timed shut-off valve for a nitrogen cylinder?

 

[Robotstar5]

Does it have to be cylinder mounted or could you use a solenoid valve downstream with a timer relay?