Hand pump connections question

[bman1]

Hi I have just purchased a hand pump and I am not sure what the 2 John guest connections on the back are for, I can see the beer line connects to the barbed fitting at the bottom but not sure what the other 2 connectors are for, I am going to connect the pump to my corny keg and fit a check valve, but I was wondering what the other 2 connections on the back are for. If anyone could help that would be great.

 

[crowcrow]

I might be wrong, but I believe the two jg fittings are for a 'water jacket' that would have cold water being circulated across all the beer engines to keep the beer 'loaded' cold. Benefits both a colder pint but also if beer warms in the engine it will start to trickle out (and be more likely to degas/get flatter).