Crown Urn Tap Thread Size?

[Hefty]

Hi all,
I've done a bit of searching here and on Craftbrewer, where I bought my urn from, and I can't find my answer:

Does anyone know what size thread is on the shank of the tap in a 40L crown urn and how it is sealed? I can't see any kind of washer in there but maybe it's covered by the nut on the inside?
I'd like to replace mine with a ball valve and barb to match my mash tun, kettle and associated tubing. I've been losing too much heat and missing infusion temps from doughing in using a 5 litre jug filled from the tap.
I'm trying to determine whether or not I'll need to drill it out more or if it's something common like 1/2" BSP etc. I would just pull it off to find out but if it is sealed in a way other than a washer behind the nut, I didn't want to break it and risk a leak if I have to re-assemble the current set up.

Any help would really ease my paranoia!
Cheers!
Jono.

 

[edschache]

There's a standard size that fits, I swapped mine out when I first got the urn - just call Ross/Anthony at Craftbrewer.

 

[OneEye]

It's definitely a 1/2" BSP. I replaced mine with a ball valve... easier to get the hoses on and off

 

[Hefty]

Cheers guys! So is it just a standard nut and silicone/neoprene/norprene washer job to seal it?

 

[Amber Fluid]

1 x SS Nipple
2 x SS Washers
1 x 1/2" Barb
2 x 1/2" Lock Nuts
2 x Silicone O-Rings

Order to install is...

nut | washer | O-Ring | Urn wall | O-Ring | Washer | nut

Don't over tighten it or you will buckle the wall of the urn.