How to improve the sealing performance of the ball valve?

The cast stone ball valve is an ideal opening and closing device in the ash slag pipeline. The quality of the upper seal directly affects the quality and service life of the valve. How should we improve the sealing of the ball valve?

 

 

Ball valve structure improvement and abrasive tool design

1. X-shaped sealing ring structure

There are sealing surfaces around the X-shaped valve sealing ring, and there are lubrication grooves on the inside and outside of the sealing ring. This structure is better than the O-shaped valve sealing ring, with low installation accuracy, good reliability, no maintenance, low price, and the adjustment of the compression amount has been widely used in the sealing of cast stone valves of various pressure levels, which can effectively prevent leakage, greatly extend the service life of the valve, and improve the reliability of the ball check valve and brass ball valve.

 

 

2. X-shaped sealing ring material

The X-shaped sealing material uses polyurethane (CPU) material, which can effectively solve the problems existing in the traditional O-shaped sealing ring. Pouring polyurethane is a kind of sealing material that has been adopted internationally. It has large elastic modulus, good physical and mechanical properties, and can withstand large impact loads. Polyurethane has basically solved the problem of hydrolysis resistance, and the temperature resistance level is also continuous improvement has greatly expanded the application areas of polyurethane.

 

 

3. The principle of ball valve sealing

Its working principle: when the bolts are tightened, the packing gland moves downwards to compress the adjusting gasket. Through the squeezing of the V-shaped packing pad, the inner and outer lips of the X-shaped sealing ring are simultaneously attached to the sealing surface of the shaft and the hole. To ensure the reliability of the seal, its main sealing performance depends on the pressing force of the tightened bolts during assembly, and has nothing to do with the accuracy of the shaft and hole dimensions.

 

 

4. Abrasive tool design

*Guarantee product usage requirements and meet design requirements;

*Easy demoulding and cleaning, convenient operation;

*Low manufacturing cost;

*The abrasive material is suitable for 45 steel;

*The shrinkage rate is designed according to 1.5%~1.7%;

*10° slope positioning without flash, product accuracy is guaranteed, and yield is high;

*The abrasive tool is composed of upper mold, inner mold and outer mold.

 

 

5. Packing cavity size

The packing chamber determines the quantity of seasoning according to the pressure of the ball valve and the size, and the width is determined by the size of the shaft. For pressures of 0.6~2.5MPa and below DN250mm, prevent one X-shaped sealing ring; for 2.5~10MPa and above DN300, place two X-shaped sealing rings. The size and depth of the packing cavity is determined by the height of the seasoning pad, pressure transmission ring, and X-shaped sealing ring.

 

 

6. Pressure transmission ring

The pressure transmission ring is set at high pressure and large diameter. It is installed between the two sets of X-shaped sealing rings. Its main function is to transmit the upper pressure, change the stress state of the X-shaped sealing ring, and make the X-shaped sealing ring bear the force. And radially deform to achieve sealing performance.

 

 

Through the improvement, the valve structure is more reasonable, the sealing is more reliable, raw materials are saved, the cost is reduced, and the service life is improved, the modification is quick, and the investment is small, which meets the needs of users. Follow us to learn more about motorized ball valve, electric ball valve or trunnion ball valve.