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Main Drain Hydro Relief Valve 1.5 inch ABS HD34


The Main Drain Hydro-static Relief Valve (HRV) is designed to allow ground water & pool water to equalise. In the event of the local water table rising (flooding) there is a high risk of the liner (if fitted) being lifted or worse the pool body 'popping' or floating out of the ground. Typically when the pool is empty or the water level is low the risk is highest. This is because the pool shell by its nature is water tight & therefore acts like a boat. Once the surrounding water exceeds the level in the pool the process starts. A pool under this extreme pressure will not last very long & only a few feet of water is needed to create the required force to 'pop' the pool. On most occasions the pool will fail or 'break its back' (as we say in the trade) as it is not designed to support its own weight. This one-way valve allows the water level to rise & flow into the pool if the pressure is great enough.
Price: £19.99
Item price: £19.99 inc VAT
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