Pump seal failure of the power dynamic seal and screw sealing

Vice impeller plus parking seal pumps in operation , the pressure generated by the impeller , deputy head of the main impeller exit equilibrium pressure liquid to achieve seal. Parking , vice impeller does not work, it is required to solve the parking with parking seal leaks that may arise .
Vice impeller sealing structure is simple , reliable sealing , long life operation can achieve watertight , so the transport medium containing impurities often used on the pump . Vice impeller good sealing effect is conditional, ie, the working pressure must not exceed the allowable working pressure . Once exceeded, will have a serious leak. Working pressure change is mainly due to the pump suction pressure changes , seal strap so the use of auxiliary impeller seal pump inlet pressure of the pump must make strict rules , otherwise the seal will fail . Since the form of sealed parking lot , after the failure can easily find that this will not repeat .
Spiral Seal
Spiral seal is a dynamic seal form, it is the rotating shaft or sleeve accommodating the shaft of the helical groove machining , between the shaft and the sleeve filled with a sealing medium . The rotation axis of the spiral grooves pump delivery resulted in a similar effect , thereby preventing leakage of the sealing liquid . The size of the sealing ability of the spiral angle , pitch, tooth width , tooth height , the role of the tooth length of the gap between the shaft and sleeve size. Since the friction between the seals does not occur , and therefore long life, but because of structural limitations of space , the screw length is generally short ,metal seal and thus the sealing capacity has been limited . Slow down and use the pump when the sealing effect is greatly reduced.