New Stem Technology
Valve stem, the English name valve stem, is an important part of valve accessories. It is used for the transmission of valves, the upper actuator or the handle. The lower part directly drives the valve core to move or rotate, in order to realize the valve switch or regulation.
The valve stem is not only a moving part and a stress part, but also a sealing part in the opening and closing process of the valve. At the same time, it is impacted and corroded by the medium, and it also rubs against the filler. Therefore, when choosing stem material, it is necessary to ensure that it has sufficient strength, good impact toughness, abrasion resistance and corrosion resistance at the specified temperature. The valve stem is a fragile part, and the mechanical and heat treatment properties of the material should be paid attention to when selecting the valve stem.
Stem type
Stem types are: globe valve stem, gate valve stem series, ball valve stem, butterfly valve stem, safety valve stem, oil field valve stem, forged steel valve stem, marine valve stem, soft sealing valve stem, stainless steel valve stem series, large valve stem, copper valve stem and a series of valve stem.
Stem nut and stem are matched by threads, directly bearing the axial force of the stem, and the friction between the plate and the bracket and other valves. Therefore, in addition to a certain degree of strength, the stem nut also requires small friction coefficient, stainless steel, not to bite with the stem and other properties.
At present, there are more than 200 valve stem manufacturers in China. The valve stem companies are becoming bigger and bigger, and the industry competition is becoming increasingly fierce.
The new valve stem processing technology adopts self-made forging and cold extrusion forming technology, which has high thread strength, accurate accuracy, and the concentricity of the threaded part and the smooth rod part is the same. It overcomes the problems of traditional scrapless thread rolling, such as easy distortion, vulnerable rolling die, etc. The precision of the smooth rod part achieves mirror effect after adopting patented technology, and the opening and closing of the smooth rod part is easier. Sealing performance is good, and then the key parts of the valve stem reversal using numerical control one-time forming, tension, torsion, from many aspects to ensure the quality of product components.
First, the valve stem is formed by self-made forging and cold extrusion. The thread strength is high and the accuracy is accurate. It completely solves the problem that the traditional valve stem thread uses spiral flying cutter and the thread accuracy is not accurate.
Secondly, the concentricity of the threaded part and the smooth rod part is the same, which overcomes the difficult problem of traditional scrapless rolling die which is easy to twist, deform and break in the domestic rolling process for a long time.
Thirdly, the patented technical precision of the polished rod part achieves the mirror effect, the opening and closing is easy, and the sealing performance is good, which solves the problems of low precision and long time-consuming of the original polished rod part grinder.
Fourthly, the reverse part is formed by NC technology at one time, which has high precision and good sealing performance. It also eradicates the problem that the original reverse part is reversed sealed by two clamps, poor concentricity and easy leakage of reverse seal. The end part is divided by milling machine indexing plate, and the processing is slow and time-consuming.
Fifthly, the T-groove at the end is forged with high efficiency and low cost. The whole production process of valve stem has reached the international advanced level.
