Type of stem

Valve stem, English name is valve stem, which is an important part of valve accessories It is used to drive and connect the actuator or handle of the valve, and directly drive the movement or rotation of the valve core below to realize the valve opening and closing or regulating functions In the process of valve opening and closing, the valve stem is not only a moving part, a stressed part, but also a seal At the same time, it is impacted and corroded by the medium, and also has friction with the filler Therefore, when selecting the stem material, it must be ensured that it has enough strength, good impact toughness, scratch resistance and corrosion resistance under the specified temperature The valve rod is a vulnerable part When selecting, attention should be paid to the mechanical processing performance and heat treatment performance of the material Stem types: stop valve stem, gate valve stem series, ball valve stem, butterfly valve stem, safety valve stem, oilfield valve stem, forged steel valve stem, marine valve stem, soft seal valve stem, stainless steel valve stem series, large valve stem, copper valve stem and a series of valve stems The valve stem nut and the valve stem are matched with the thread to directly bear the axial force of the valve stem, and the plate is in the friction with the valve parts such as the bracket Therefore, in addition to a certain strength, the stem nut is also required to have small friction coefficient, no rust, no seizure with the stem and other properties At present, there are more than 200 stem manufacturers in China, and the stem companies are becoming larger and larger, and the industry competition is increasingly fierce    The new stem processing technology adopts the self-made forging cold extrusion molding technology, with high thread strength and accurate accuracy, and the concentricity of thread part and smooth rod part is the same, which overcomes the problems such as the traditional non chip rolling thread is easy to twist, deform, and vulnerable rolling thread die The precision of smooth rod part after adopting the technology reaches the mirror effect, and the opening and closing are easier, and the sealing performance is good, and the key part of stem is reversed closed CNC one-time forming, tensile, torsion, from many aspects to ensure the quality of product parts First, the valve rod is forged and cold extruded by self-made forging, with high thread strength and accurate accuracy, which completely solves the problem that the original traditional valve rod thread uses a spiral flying knife, with inaccurate thread accuracy Second, the concentricity of the thread part and the polished rod part is the same, which overcomes the old and difficult problem that the traditional non chip rolling thread is easy to twist, deform and wear in the domestic rolling process for a long time Third, the smooth rod part adopts technical precision to achieve mirror effect, easy opening and closing, good sealing performance, which solves the problems of low precision and long time consumption of the original smooth rod part grinder Fourth, the inverted part adopts numerical control technology for one-time forming, with high precision and good inverted light sealing performance It also eliminates the problem that the original inverted part adopts two times of clamping and inverted sealing, with poor concentricity and easy leakage of inverted sealing The end part adopts milling machine index plate for indexing, and the processing is slow and takes a long time Fifth, the T-groove at the end adopts forging forming technology, which has high efficiency and low cost The whole production process of valve rod has reached the international advanced level     This new technology not only has low processing cost of stem and screw rod, but also ensures the quality of product parts and reduces the cost of products Moreover, the valve stem and screw rod are assembled in the valve, which makes the opening and closing moment of the valve small, easy to open, labor-saving, and time-saving The surface is smooth and coaxial, which makes the sealing performance high It also has many advantages such as position resistance, torsion resistance, high strength and service life of the valve Point.