A42H Safety Valve　IV. Spring Full-Lift Safety Valve

　　A42H-16C A42H-25C A42H-40 A42H-64 A42H-100 A42H-160 A42H-320 A42Y-16C A42Y-25C A42Y-40 A42Y-64 A42Y-100 A42Y-160 A42Y-320 A42Y-16P A42Y-25P A42Y-40P A42Y-64P A42Y-100P A42Y-160P A42Y-320P A42Y-16R A42Y-25R A42Y-40R A42Y-64R A42Y-100R A42-160R A42Y-320R A42W-16P A42W-25P A42W-40P A42W-64P A42W-100P A42W-160P A42W-320P A42W-16R A42W-25R A42W-40R A42W-64R A42W-100R A42W-160R A42W-320R A42F-16C A42F-25C A42F-40 Pulse Safety Valve Installation Instructions: ①This valve should be used in conjunction with the A49H-4 main safety valve. ②The pulse safety valve must be installed strictly vertically, the lever should be kept horizontal, and the clearance on both sides of the guide fork must be uniform.

③Before installing the pulse safety valve, the pipeline should be flushed clean. ⑤There should be a long distance between the outlet pipe of the pulse safety valve and the inlet pipe of the main safety valve. The distance between the electric contact pressure gauge and the inlet pipe of the main safety valve should not be less than 5 times the diameter of the main safety valve inlet pipe, to prevent the exhaust from affecting the accuracy of the electric contact pressure gauge and the pulse safety valve when the main safety valve operates.

　The A47H spring slightly open safety valve is suitable for equipment and pipelines containing air, ammonia, petroleum gas, and other media with working temperatures ≤200°C. The A21W type is suitable for equipment and pipelines containing corrosive gases or liquids with working temperatures ≤200°C. The A21F type is suitable for equipment and pipelines containing liquefied petroleum gas, petroleum gas, etc., with working temperatures ≤200°C, serving as an overpressure protection device. When the pressure in the equipment or pipeline exceeds the allowable value, the valve automatically opens and discharges fully; when the pressure drops to the specified value, the valve automatically closes, ensuring the safe operation of the equipment and pipeline.

　　Structural Overview

　　1. The spring slightly open safety valve features a simple structure, good sealing performance, accurate opening pressure, high discharge capacity, small reseating pressure difference, and convenient adjustment.

　　2. Nozzle-type valve seat: The valve seat is a Weir-type nozzle seat. When steam flows through the outlet of the valve seat, it reaches sonic speed, resulting in a high discharge coefficient. The sealing surface of the valve seat is overlay welded with cobalt-chromium-tungsten hard alloy, providing wear resistance, erosion resistance, and long service life.

　　3. Thermoelastic valve disc: The valve disc is designed with a thermoelastic structure, utilizing slight deformation under medium pressure to improve sealing capability and overcome pre-leakage phenomena when the safety valve approaches the set pressure under medium pressure. The sealing surface of the valve disc uses advanced laser quenching technology to improve hardness, wear resistance, and impact resistance.

　　4. Adjusting nut: By adjusting the adjusting nut, the spring compression can be modified, allowing the valve to easily and quickly achieve the precise set pressure.

　　5. Backpressure adjustment sleeve: An auxiliary mechanism for adjusting the backpressure of the valve disc. By adjusting the backpressure adjustment sleeve, an appropriate reseating pressure difference can be obtained. Moving it upward reduces the valve backpressure, while moving it downward increases the valve backpressure.