Expansion tanks for pressurized fluids and diaphragms therefor

Claim 1

An expansion tank for pressurized fluids comprising: first and second shell halves, each of said shell halves including a central wall portion and a sidewall merging at one extremity thereof with said central wall portion and terminating at the other extremity thereof in a peripherally extending outwardly directed skirt; and shell halves being oriented with the said extremities thereof having the respective said skirts facing toward each other, whereby said skirts are generally superposed; an opening in one of said shell halves for the passage therethrough of a liquid; an opening in the other of said shell halves for the passage therethrough of air; a diaphragm formed of elastomeric material extending across the interior of the tank and having a peripheral edge which is between said superposed skirts and said tank shell halves, said diaphragm comprising a central sheet terminating in said peripheral edge, said peripheral edge being formed by a peripherally extending column integral with and formed of the same material as said central sheet and a pair of flange elements and a web element therebetween integral with and extending inwardly of said sheet from said column, each of said flange elements being spaced from an opposed side of said web element to form an annular slot therewith; said skirts of said shell halves being releasably and sealingly positioned within respective ones of said annular slots such that said diaphragm divides the interior of the thus formed tank into a pair of chambers sealed relative to each other and relative to the ambient atmosphere external to the tank; and locking means for releasably maintaining said shell halves and said peripheral edge of the diaphragm in joined sealing relationship.