Behaelter,insbesondere Schwimmbecken

1,056,630. Swimming pools. VEREINIGTE METALLWERKE RANSHOFFENBERNDORF A.G. Oct. 25, 1965 [Oct. 23, 1964], No. 45113/65. Heading A4N. In order to prevent the metallic liner of a swimming pool or water storage tank from buckling under the lifting pressure of ground water, the portion of the liner below the water table is provided with an exterior drainage cavity which can be connected to the interior of the pool to equalize the interior and exterior pressures. The liner 19 may be part of a diaphragm safety valve (Fig. 2, not shown) and have a valve ring 16 which is lifted off a fixed seating 13 when the ground water pressure increases. As shown, a pool 1 is drained through a pipe 4 into a shaft 5 having a discharge outlet 9 and a suction line 8. Safety valve 12 allows the ground water drained through pipe 3 to flow into the empty pool 1, even when valve 6 has been inadvertently closed. An aluminium liner 19 may be provided.