Heat installation for liq. circulation system - has hot gas heating vessel with two outlets to each of two reserve cylinders and third outlet to central heating radiators
NL7711068A
Plug type mains water tap - has plug with hexagonal flange working in mating portion of boss
GB1538653A
Heat exchanger for a heating vessel
NL7612733A
Boiler heat exchanger unit - gives improved heat exchange as flue gases follow a turbulent zigzag path between series of pyramid shaped pegs
DE2649635A1
Sectional boiler heat exchanger - has bosses on adjacent covers fitting between each other to give zigzag smoke flow