Hi Steeley
I had loads of trouble with the S30 pin valve not holding pressure. i fitted a Schrader bike Valve on the lid (so as to add and remove pressure with a bike stirrup pump first. I took the S30 Pin Valve off the lid removed the outer ring with the hole in ,and got a bit of Old bike innertube cut a length off about 2.5 3 inch's long and made it just wider than the Rubber thats over the hole on the valve then i put the S30 valve back in the lid and wrapped the strip of bike innertube around the rubber stretching it tight as it goes around the valve, then placed the outer ring with the hole in over the innertube strip (its a bit tight)so there is no gap on the inside of the outer ring, put the locking nut back on ,put the lid back on the king Keg stick some water in fit the lid tight then put some air in with the bike pump to about 10psi then using soapy water check for air leaks If you find a leak just check your nuts and seals and tighten according. i done this and works a treat. you can buy a new lid from Ballihoo with the Schrader valve already fitted if you want. no need to buy new rubbers