Ball valve hole size - question.

[Cully]

I an buying a plastic boiler which the supplier can cut holes in for elements and also for a tap. He lists three sizes of hole that he can cut, the tap sized one being 22mm. The Bal valve that I am buying is one from the Malt Miller, which he says fits a 21mm hole. Does the spare mm matter or can I just proceed and fit one to the other?

[Wonkydonkey]

If I remember right, a ball valve can be threaded into a 20mm hole. But it's a tight fit and threading it in is apita,
If the guy cuts a 21 mm hole, by the time it's cleaned up, it's gonna be 22mm in plastic.
It nothing a washer will sort out IMHO.

Hope this helps

[Cully]

This is the one I planned on getting, it has its own bulkhead fitting with washers - would I have to make a bigger washer and where would it go?

http://www.themaltmiller.co.uk/index.ph ... ductId=194

[Wonkydonkey]

The way I see it, the thread on the bulkhead fitting is 21mm diameter, those nuts and fibre washers will easly seal a 22mm hole. It may move a little bit, if it's not tight.

Edit: you may have to use a bit of Ptfe tape on the thread.

[Cully]

Cool. Cheers for the help, I might get my first AG brew before the month is out! Drooling at the thought tbh.