Pneumatic dome valves used to be used as feed valves for warehouse pumps in the dry ash delivery system at coal fired power plants.The dome valve's sealing principle is: The valve ball do not contact with the rubber sealing ring in the process of closed, with 1 ~ 2 mm gap.The rubber seal ring begins to be inflated after the ball is rotated in place, the sealing ring close to the top of the ball after sealing ring expansion, however the media particles fill a gap of 1-2mm when the seal ring is inflated.
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It is easy to cause the sealing untight and leakage.The gap between the seal ring and the ball top is scoured by the media particles when the tank pump is pressurized by the air. It is easy to be damaged for The sealing rubber ring and the ball surface,which increased the times of replacement of sealing rubber rings. If the surface of the semi-sphere is badly scoured and worn, a lot of maintenance work must be carried out in the ash operation.The pneumatic ceramic rotary feed valve solves this problem .
 
Our pneumatic ceramic rotary feed valve avoids the shortcomings of dome valve, sealing material adopts wear-resisting ceramic seal,it will automatically generate grinding and polishing cleaning between the sealing surface in the process of the valve opening and closing , so that the sealing surface get effective protection, which prolong the service life of the valve, avoids much maintenance work, so pneumatic ceramic rotary feed valve is the ideal replace product of dome valve.