"Hi all.
Just wondering if anyone can tell me how these things work and what is required to make them work?
cheers"
Tony,
They work thru a series of one way valves and a piston arrangement.
The movement of the handle pulls a piston up and creating a vacuum and pulling the beer from the keg. Upon righting the handle depresses the piston forcing the beer thru a valve in the piston and, being blocked by the valve its passed thru, then trapping it above the piston. On the next pull on the handle it passes the beer thru the 'goose neck' and 'sparkler tip'(if it has one), and pulling the next half/quarter/pint up into the engine body(piston arrangement).
As Doc has mentioned a 'breather' is required to keep the head space in the keg filled with Co2. I feel a reg set at low pressure would allow the beer to be forced thru the beer engine and out the tip and filling your drip tray with beer.
The breather only allows one atmosphere of Co2 pressure into the keg/cask when a vacuum is created when you draw off a pint, so MAYBE even a change in atmospheric pressure may give you a 'drippy tip'
and we wouldn't want to hear about that, would we!!