difference between low suction and high suction sea chest for sea water from water box.?
ship side valves can be arranged with high and low suctions or fitted to water boxes..high suctions are intended for shallow water to reduce the intake of sediment. low suctions are used at sea,to reduce the risk of drawing in air and losing suction when the ship is rolling.
a water box should be constructed with a minimum distance of 330mm between the valve and the top,for accumulation of any air which is then removed by a vent.
ship side valve bodies for the sea water inlet must be of steel or other ductile metal.