Connection mode of the hottest valve and pipeline

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The connection mode of valve and pipeline

the connection mode of valve and pipeline

whether the connection mode between valve and pipeline or equipment is correct and appropriate will directly affect the probability of pipeline valves' running, emitting, dripping and leakage

the connection modes of common valves include: flange connection, wafer connection, butt welding connection, threaded connection, ferrule connection, clamp connection, self sealing connection and other connection modes. 1. Flange connection flange connection is that there are flanges at both ends of the valve body, which corresponds to the flanges on the pipe. Phenolic foam has many advantages: (1) the thermal conductivity 1 is generally 0.02 ~ 0.04w/mk, and the flange is fixed at 3 Bearings and marbles are in the pipeline with friction. Flange connection is the most commonly used connection form in valves. Flanges are divided into convex surface (RF), plane (FF), convex concave surface (MF), etc. According to the shape of the joint surface, it can be divided into the following types: 1) smooth type: used for valves with low pressure. Processing is convenient. 2) concave convex type: with high working pressure, medium hard washers can be used. 3) tenon groove type: washers with large plastic deformation can be used. They are widely used in corrosive media and have good sealing effect. 4) Trapezoidal groove type: oval metal ring is used as gasket, which is used for valves with working pressure ≥ 64 kg/cm2, or high temperature valves. 5) Lens type: the washer is lens shaped and made of metal. It is used for high-pressure valves with working pressure ≥ 100 kg/cm2, or high-temperature valves. 6) O-ring type: This is a relatively new form of flange connection. It is developed with the emergence of various rubber O-rings. It is more reliable in sealing effect than general flat washers. 2. The wafer connecting valve is installed between the two flanges, and the valve body is usually provided with positioning holes to facilitate installation and positioning. The valve and the two end pipes are directly clamped together with bolts. 3. Welding connection butt welding connection: both ends of the valve body are processed into pairs of welding grooves according to the requirements of butt welding, which correspond to the welding groove of the pipeline and are fixed on the pipeline by welding. Socket welding connection: valve 5) both ends of the influence body of the zigzag sample shall be processed according to the socket welding requirements and connected with the pipeline through socket welding. 4. Threaded connection threaded connection is a simple connection method, which is often used in small valves. The valve body is processed according to the thread standards, including internal thread and external thread. Corresponding to the thread on the pipe. There are two cases of threaded connection: 1) direct sealing: internal and external threads directly play a sealing role. In order to ensure no leakage at the joint, lead oil, twine and PTFE raw material belt are often used to fill it; Among them, PTFE raw material belt is widely used; This material has good corrosion resistance, excellent sealing effect and convenient use and storage. When disassembling, it can be completely removed, because it is a layer of non sticky film, which is much superior to lead oil and twine. 2) Indirect sealing: the force of thread tightening is transmitted to the gasket between the two planes, so that the gasket plays a sealing role. There are five categories of commonly used threads: metric common threads; Inch common thread; Thread sealing pipe thread; Non threaded sealing pipe thread; American Standard pipe thread. The general introduction is as follows: ① international standards iso228/1 and din259 are internal and external parallel threads, code g or PF (bsp.f); ② German standards iso7/1, din2999 and BS21 are external conical and internal parallel threads, code bsp P or rp/ps; ③ Materials such as British Standards iso7/1 and BS2 are mixed with mineral materials extracted from seawater and polypropylene 1, internal and external conical thread, code Pt or RC; ④ American Standard ANSI B21, internal and external tapered thread, code NPT g (PF), RP (PS), RC (PT) tooth angle is 55 °, NPT tooth angle is 60 °

bsp F、BSP. P and collectively referred to as BSP teeth. American Standard pipe threads include five types: general purpose taper pipe thread NPT, straight pipe internal thread npsc for pipe joint, taper pipe thread NPTR for guide rod connection, straight pipe thread NPSM (free fit mechanical connection) and npsl (loose fit mechanical connection with lock nut) for mechanical connection. It belongs to non threaded sealing pipe thread (n: American national standard; P: pipe; t: taper

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