Method for pressure venting trapped space between plastic liner and support has integral valves opened by pressure displacement of liner

摘要

A method for pressure venting the trapped spaces between a plastic liner (1) and a support surface (14) has valves (3, 4, 5) spaced about the liner and with supports (7, 8) fitted into the support structure by threaded mountings in fixed sleeves (15). Excess pressure in the trapped spaces causes the plastic liner to move, thereby opening the venting valves, and preventing damage to the liner.