Lightweight composite overwrapped pressure vessels with sectioned liners

A lightweight composite overwrapped diaphragm accumulator comprising:

• (i) an accumulator housing consisting essentially of:
• (a) top and bottom liner sections assembled together to form said accumulator housing, wherein a peripheral edge of one of said top or bottom liner sections contains a channel such that the peripheral edges of top and bottom liner sections that are assembled together forms a slot, and wherein said top and bottom liner sections comprise first and second orifices, respectively, for introducing first and second pressure mediums, respectively;
• and
• (b) a diaphragm subdividing an interior of said accumulator housing into first and second pressure medium storage areas, said first pressure medium storage area accommodating first pressure medium, said second pressure medium storage area accommodating second pressure medium, wherein a peripheral edge of said diaphragm is inserted into said slot, thereby securing the peripheral edge of said diaphragm therebetween;
• and
• (ii) composite overwrap encasing said accumulator housing and providing mechanical strength for holding said accumulator housing under pressure and to provide a sufficient stiffness and mechanical strength to prevent leakage of first or second pressure medium,
• wherein said lightweight composite overwrapped diaphragm accumulator is subjected to pre-stressing (a) during said step (i)(a), (b) during said step (ii), or (c) a combination thereof.

A method for producing a composite overwrapped pressure vessel, said method comprising:

• (i) forming a liner body from two sections without welding, threading, crimping or bonding by adhesive;
• and
• (ii) overwrapping said liner with a composite material thereby providing mechanical strength for holding said pressure vessel under pressure and to provide a sufficient stiffness and mechanical strength to prevent leakage of a fluid medium contained within said liner,
• wherein said composite overwrapped pressure vessel is subjected to pre-stressing:
• (a) during said step (i),
• (b) during said step (ii),
• (c) during an autofrettage process, or
• (d) a combination thereof.