These ball lock posts include a 1/4 inch BSP thread so you can attach it to a wide range of other fittings. The posts include a 20mm long thread, an o-ring, poppet, locking nut and short dip tube.  can be purchase separately . This would enable you to make a keg out of any pressure vessel if you wanted to. 
Please note the Liquid Bulkhead does not have the score around the edge. The score around the edge is for gas. Have a look at the photos if you are confused.

Liquid Ball Lock Post with 1/4 Inch BSP Bulkhead Assembly
These ball lock posts include a 1/4 inch BSP thread so you can attach it to a wide range of other fittings. The posts include a 20mm long thread, an o-ring, poppet, locking nut and short dip tube. can be purchase separately . This would enable you to make a keg out of any pressure vessel if you wanted to.