1. The new type of stem thread is extruded by self-made, with high strength and accuracy.
2. The concentricity of the screw part and the polished rod part overcomes the problem of easy distortion and loss of the die in the domestic rolling process for a long time.
3. The precision of polished rod can achieve mirror effect, easy opening and closing and good sealing.
4. The inverted shutoff position adopts numerical control technology to form once, with high precision and good sealing performance.
5. T-groove of end part adopts forging and pressing molding process, which is of high efficiency and low cost.
6. The whole set of stem production process reaches the international advanced level. Under the condition of strong corrosion, volatile and toxic and harmful process conditions, once the stem seal is damaged, the process medium of strong corrosion, volatile and toxic and harmful leakage from the control valve stem will bring serious consequences to the surrounding environment and personal safety.The use of bellow valve stem seal form is a solution to the above problems.Bellows are usually made of stainless steel.This special bonnet structure protects the packing box of the control valve from contact with the fluid. Once the bellows break, the stuffing box structure above the bellows prevents serious consequences of failure of the bellows break.In practice, the selection of bellows seal form should fully consider that the pressure rating of bellows seal will decrease with the increase of temperature, there can be no solid particles in the fluid, and the maximum cycle operation life of bellows material.In places where stainless steel is not resistant to the corrosion of certain process media, for example, if the process medium is wet chlorine, the trace hydrochloric acid contained in wet chlorine will cause the stainless steel corrugated pipe to be corroded quickly.