The cause of the high temperature pneumatic ball valve seal seat damage

to heat pneumatic ball valve for high temperature and high pressure ( 。 MPa saturated steam during the trial, found the seal damage, damage to the seal seat as shown. Through careful observation, discover the damaged are medium, import the seal seat and damage are the same parts, and the outlet seal is in good condition. First in the pneumatic ball valve closed, access to. MPa saturated steam, preheat l minutes, open the pneumatic ball valve, and then check whether the seal seat is hurt bad; In the condition of pneumatic ball valve to open, then pass into the. MPa saturated steam, preheat l minutes, close the pneumatic ball valve, and then check whether the seal seat is damaged, the results of two experiments are inlet side seal seat damage occur. By pneumatic ball valve sealing principle of structure to the floating ball is under the action of medium pressure, sphere produce certain displacement compression on the outlet seal seat, thus guarantee the outlet seal, so the inlet seal damage, does not affect the pneumatic ball valve sealing performance, has certain concealment. After many times when the pneumatic ball valve opening and closing action, inlet side sealing damaged part will happen shear falls off phenomenon.