Pneumatic ball valve sealing improvement

a, pneumatic ball valve sealed
and the analysis of the current situation of casting ball pneumatic valve is ideal in the ash pipe opening and closing device, its sealing quality directly affect the quality of the pneumatic valve and service life. Used O shaped rubber seal structure form, that is, on the shaft processing O ring is put inside the ring groove, then assembled into a set of parts processing out of the hole and shaft and hole sealing, the sealing performance of the structure depends on the amount of interference when the design, namely the O ring compression and machining precision of hole and shaft parts. Interference quantity is too small, sealed performance is poor, the amount of interference is too large, easily when assembling crowded bad O ring, seal failure.
the sealing structure is simple, easy assembly. But if the shaft, hole machining accuracy is not high, or difficult to improve the machining precision, in addition to basic sealing performance is difficult to guarantee or difficult to further improve the accuracy, its main drawback is that the sealing material, this seal structure is applicable in the cylinder, hydraulic cylinder, cast stone balls in ash water use pneumatic valve seal is difficult to ensure the sealing performance. Due to the pneumatic ball valve switch belongs to the part of the transformation of the back, often need to ° switch. Because of the pneumatic valve stem and valve body to move between cooperate, have a certain gap, pneumatic valve in switch medium effect on the sphere of large thrust, must make the pneumatic valve stem produces certain tilt, aerodynamic force towards the side of the stem, the side is badly worn, contains a lot of suspended matter and ash water erosion on sealing ring. Pneumatic valve stem position caused by O ring life cycle is short, leak phenomenon often happens, also caused certain effects in the field environment, therefore decided to improve the sealing structure forms and materials, the improved main starting point is to make its in the shaft and hole assembly, can be adjusted through the compression quantity and don't have to greatly improve the shaft, hole machining precision can be guaranteed effectively sealed.
2, pneumatic ball valve structure improvement and abrasive tool design

X, X ring structure around the ring has a sealing surface, are on the outside of the sealing ring in lubricating groove, this kind of structure is better than that of O ring, the installation precision is low, the use of good reliability, no maintenance, low prices, can also through the gasket compression quantity adjustment, has been widely used in various pressure levels of cast stone pneumatic valve sealing, can effectively prevent the occurrence of leakage phenomenon, greatly extend the service life of the pneumatic valve, to improve the reliability of pneumatic valve.
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X X ring material form sealing materials using polyurethane ( CPU materials, can effectively solve the problems existing in the traditional O ring. Type casting polyurethane is now on the international comparison by a sealing material, the modulus of elasticity is big, physical and mechanical performance is good, can bear bigger impact load, and polyurethane has been basically settled the problem of hydrolysis resistance, heat resistance level is in constant increase, greatly expands the application fields of the polyurethane. With a molded polyurethane x-shaped seal production, the craft simple, the manufacturing cost is low. Their level of pressure can reach MPa is even higher, effect of pressure also is quite good, basic can reach zero leakage.
, pneumatic ball valve sealing principle, its working principle:
when tightening bolts, packing gland is downward pressure adjustment gaskets, by extrusion V packing cushion, make x-shaped seal lips, in the outside lip tiejin shaft and hole sealing surface at the same time, guarantee the reliability of the seal, the sealing performance depends on the main assembly screw down the bolt clamping force, the relationship between shaft and hole size accuracy without too much.

and abrasive tool design to ensure product requirements, comply with the design requirements;
demoulding, qing mould is easy, easy to operate;
the manufacturing cost is low;
abrasive materials for steel;
shrinkage rate. % ~。 % design;
° slope position without flash, products guaranteed accuracy, high yield;
grinding tool consists of upper die, die, die in.

and packing chamber size packing chamber based on pneumatic ball valve pressure and diameter size decided dressing quantity, width is determined by the size of the shaft. Pressure. ~。 MPa, DNmm prevent an X under seal; 。 ~ the placement of MPa, DN above two X sealing ring. Packing chamber by dressing pad size depth, pressure transfer ring, x-shaped seal height.

pressure relay, pressure transmission is set up in high pressure and large diameter, it is installed between the two groups of X ring, its main function is passed the above pressure, change x-shaped seal bearing state, make X ring stress and radial deformation, reach the sealing performance.

, X ring, finite element analysis x-shaped seal is a kind of lip seal, with pressure ring ( Packing gland and supporting ring ( Packing mat combination, it can effectively prevent the medium leakage.

X, X ring force analysis force by pressure ring ring ( Packing gland pressure is passed to the X ring, sealing ring at the bottom of the bearing ring ( Packing cushion strength of three way, shaft and pneumatic sealing face of valve hole stress evenly, can get ideal sealing effect.
3, about
the end of the pneumatic ball valve sealing by improving, pneumatic valve structure more reasonable, more reliable sealing, save raw materials, reduce the cost, and improve the service life and retrofit is fast, less investment, to satisfy the users' needs.