Well cheers for that you've just saved me a few quid.
Its more for the ascetic reasons, than the other valves that are available.
I had one of those brass chromed non-return valves before my diffuser it leaked Co2.
I have just orderd this http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... K:MEWAX:IT
Its only Â£4.00 so a may aswell and see how it goes its Â£10.00 elsewhere and Â£9.00 on other e-bay sites just a different colour check valve you got to laugh.
Thanks for that.