Plumbing size for 2 metre long galvanised farm water trough?

In message snipped-for-privacy@mid.individual.net>, alan_m snipped-for-privacy@admac.myzen.co.uk> writes

Isn't this likely to be sized for a conventional float valve with the supply piping linked to that?

Usually such tanks are supplied with a cover to prevent valve damage by livestock.

This is the "supplied drain bung". I've been on line and various suppliers say they come with bung but no sizes given.

Edit: I found a measuring tape and best estimate is OD of bung thread =

This is an open tank - no cover. This isn't going to be used for cattle but raised up and the intention is to fit a tap for draining down.

That normally would be 1/2" BSP though would it not?

The ones I found on agri supplier sites said 10mm drain bung, but I assumed you'd be talking about the inlet for the ball-valve?

Most farmers would just tip the trough on its side with a front end loader or similar. Quicker than faffing with a drain plug (assuming an outside trough).

Piggies of course are expert at tipping troughs over anyway, so most of the time farmer brown is putting it back upright.