It has the functions of heat resistance, acid resistance, alkali resistance, corrosion resistance, abrasion resistance, oil resistance, etc. The expansion joint (expansion joint) is mainly used to compensate for the expansion deformation of the pipeline due to temperature changes, and also for the length compensation of the pipeline due to installation and adjustment. It is mainly divided into three structural forms: elbow expansion joint, bellows expansion joint and sleeve expansion joint. Elbow expansion joint is an expansion joint that bends the pipe into a U shape or other shape (Figure 1 [Elbow expansion joint]) and compensates with the elastic deformation capacity of the shape. It has the advantages of good strength, long service life, and can be made on site. Its disadvantages are that it occupies large space, consumes more steel and has large friction resistance. This expansion joint is widely used in various steam pipelines and long pipelines. Technical standards: products shall be marked in the following order: product code, type code, structure code, performance code, working pressure, nominal diameter. The product and structure codes are specified as follows: flexible electric butterfly valve RFJ, single ball D, double ball S, elbow W, concentric reducer Yt, eccentric reducer Yp, fan coil connector F.
Mark example: RFJD-1.6 × 200,. It refers to a single spherical flexible electric butterfly valve with a nominal diameter of 200mm, and the working pressure is 1.6Mpa. Working pressure: the test pressure of the electric butterfly valve is 5 times of the working pressure, and the pressure is 3 times of the working pressure. Vacuum resistance: for electric butterfly valves with nominal inner diameter less than 300mm and working pressure more than 1.6Mpa, the vacuum resistance shall not be less than 100Kpa. For rubber with other specifications, the vacuum of the forehead shall be specified by the agreement between the supplier and the demander.
Safety evaluation of electric butterfly valve used in domestic drinking water system: safety of electric butterfly valve used in domestic drinking water system When the flat angle electric butterfly valve is used in domestic drinking water system, the water quality after passing the product shall comply with GB/T5749 Sanitary Standard for Drinking Water and GB/T17219 Safety Evaluation Standard for Drinking Water Transmission and Distribution Equipment and Protective Materials Relevant regulations and requirements. Requirements for metal flange and flat union: metal flange shall meet the requirements of GB/T9119, and flat union shall meet the requirements of GB/T3289.37. Requirements when the end face of the electric butterfly valve is reinforced with steel wire rings: when the end face of the electric butterfly valve is reinforced with steel wire rings, the steel wire rings shall be round and located in the same plane in the same year. The difference between rubber soft connection and metal soft connection: what is the difference between rubber soft connection and metal soft connection? The two seem very similar, but their functions are different. Stainless steel metal hose, also known as metal hose, metal flexible connection and stainless steel hose, has good flexibility, temperature resistance, pressure resistance and corrosion resistance, and is suitable for transmission of steam, water, oil and various industrial gases and other media.