High pressure die casting valve structure characteristics, materials, testing and transmission

1, the performance of high-pressure casting cut-off valve: Because of the high-pressure cast-off valve seat channel change is proportional to the valve stroke. High-pressure globe valve stem opening or closing stroke is relatively short, but also has a very reliable cut-off function, but also because the valve seat channel changes and the valve stroke is proportional to the proportional, very suitable for the regulation of the flow. Therefore, this type of shut-off valve valve is well suited for shut-off or regulation as well as throttling. Due to the small valve opening and closing of the cast-off valve, the sealing surface can withstand several times of opening and closing. Therefore, the shut-off valve is suitable for applications that require frequent switching and can be used in most media flow systems. Globe valves are widely used in petrochemical, power, metallurgy, urban construction, chemical and other industries. 2, the structure characteristics of high pressure casting globe valve: (1) GB flange connection, socket welding connection, butt welding connection, threaded connection globe valve series is a reference to the national standard design of conventional products, cast steel globe valve series product structure design is reasonable, Stable performance, reliable quality, easy installation, operation light and flexible features. (2) the valve disc and seat sealing surface with different hardness of carbide spray welded together. Sealed, reliable, high hardness; wear-resistant high temperature, good scratch resistance, long life. (3) stem by heat treatment, has good abrasion resistance and abrasion resistance. (4) A variety of connection types are available to meet various piping requirements and piping flange standards and flange sealing surface forms to meet various engineering needs and user requirements. 3, the selection of high pressure casting globe valve sealing material: carbon steel stop valve: valve 13Cr, seat for the WCB + HF, WC6 + HF or LCC + HF, the difference between the hardness HB ≥ 50. The spray process, in strict accordance with the spray process rules. Stainless steel shut-off valve: valve 304 or 316, the valve seat for the OCr18Ni9 + HF or OCr17Ni12Mo2 + HF, the difference between the hardness HB ≥ 50. Valves and valve seat sealing surface hardness is good with good erosion resistance, corrosion resistance, spray process, in strict accordance with the spray process rules. 4, high pressure casting valve material: 4.1 valve body, valve cover, the material is WCB, WC6, LCC, OCr18Ni9 or OCr17Ni12Mo2. The above valve material in strict accordance with the GB / T12224 "general requirements of steel valves" and the requirements of the valve material standards to choose and to ensure that the service life. Casting materials in line with GB / T12229 "general valve carbon steel casting technical conditions", GB / T12230 "general valve stainless steel casting technical conditions" and JB / T7248 "valve with low temperature steel casting technical conditions" provided for by the standard requirements. Steel castings according to the standard requirements of heat treatment, mechanical properties to meet the standard requirements. Non-destructive testing of the pressure-cast steel, the implementation of standards for JB / T6440 "valve compression cast steel radiographic inspection." All pressure forgings to JB4726 ~ 4728 "pressure vessel steel forgings" requirements. All reports are archived for on-demand inspection during valve production. 4.2 stem material is 13Cr, 304 or 316. Stem material according to the relevant valve standards for chemical analysis, mechanical performance report (tensile test, hardness test), as required, heat treatment, and provide the phase and the report card. All reports are archived for on-demand inspection during valve production. 5, high-pressure casting stop valve inspection and testing 5.1 Test Standard Valve inspection and test implementation JB / T9092 and GB / T12224 standards. Shell pressure test in the valve surface treatment and painting before. 5.2 The valve 100% pressure test before delivery, the valve pressure test at least include the following. - Shell test, the upper seal test, low pressure gas seal, high pressure water seal test, other tests specified in the specification. 5.3 After testing, drain the test body in the valve body. 5.4 All Butt Welds 100% X-ray inspection. For PN160 and above the pressure level of the valve pressure parts according to JB / T6440 do X-ray inspection .5.5 product use units have the right at any time according to the need for inspection. 6, high pressure stop valve gear: 6.1 According to the operating conditions of the globe valve, the valve operating mechanism to have sufficient torque and stiffness. 6.2 The operating body housing support and the body connected components require adequate rigidity and strength. 6.3 manual operating mechanism The maximum force of the hand wheel 35Kgf (under any operating conditions). Requires valve drive mechanism throughout the trip operation is smooth, no jam, no beating phenomenon, high precision adjustment, accurate action.