What’s wrong with this selection parameter? Waiting online! ! !
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Butterfly valve, nominal diameter: DN1600, process pipe diameter: Φ2220*10, process pipe material: Q235-B. Medium: Gas; Medium temperature: 50°C (up to 80°C); Medium pressure: 0.015 MPa; Maximum flow rate: 220,000 Nm3/h; Ambient temperature: Normal temperature. Actuator: Pneumatic actuator; Valve operation mode: Single-action, valve opens when air supply is lost; Shut-off mechanism: Solenoid valve closes quickly when powered, with a shut-off time of less than 15 seconds (adjustable); Valve opening angle: 90°; Pressure rating: PN1.0 MPa; Maximum pressure difference before and after the valve: 0.6 MPa; Leakage class: VI; Valve disc material: Stainless steel; Shut-off signal: ON-OFF 220V AC; Air supply pressure: 0.4–0.6 MPa; Equipped with air filter and pressure regulator (with pressure gauge); Equipped with limit switches for full open and full closed positions (3 signals each); Equipped with solenoid valve (single-coil): 220V AC, for continuous operation; Equipped with handwheel; Flanged connection; Includes matching installation flanges and connectors. Explosion-proof. Thank you!
Medium pressure refers to: is it the pressure before the valve, 0.015 MPa? If so, does a pressure difference of 0.6 MPA before and after the valve mean that there is a vacuum on the side behind the valve? Is this what you wait for online? I waited an hour for you to reply, but you still haven’t responded. This post was last edited by dst339 on 2009-3-23 14:19]
0.6 MPa is likely not the differential pressure of the medium; it is probably a requirement for the valve. When considering butterfly valves, it is necessary to take into account not only the pressure rating of the valve body but also that of the butterfly disc. Simply put, a butterfly valve has 2 pressure ratings. The allowable differential pressure determines the pressure rating of the butterfly valve. It would be best if you could specify which system is being used, so that we can know what’s going on without having to guess. If it is truly a vacuum behind the valve, does reverse sealing still need to be considered?
The customer also needs to recheck the drawings to confirm the parameters; this system is a gas power generation system for steel mills； There is no vacuum behind the valve, nor is there negative pressure; even if there were a vacuum, it would be impossible for the pressure in front of the valve to be 0.015 MPa, with a pressure difference of 0.6 MPa ； So I speculate that there is an issue with his pressure difference parameter; it might be related to the extreme conditions considered by the design team, where the medium pressure temporarily rises to over 0.6 MPa ； Furthermore, if the valve remains in an operating state of 0.6 MPa for an extended period, a large torque is required to open the valve, and it is difficult for the cylinder to meet this requirement. So I think there is an issue with the pressure difference parameter of 0.6 MPa. I’m not sure if my analysis is correct
If it is a cut-off valve (which closes quickly when the solenoid is activated), the fault condition should be selected as – valve closed due to loss of air pressure, and not as valve open due to loss of air pressure.
By the way, I would like to ask if there are any requirements regarding pressure difference when choosing a pneumatic actuator