A buffer valve, being a two-way valve, the buffer valve being installed on a pneumatic diaphragm valve, the pneumatic diaphragm valve including a pneumatic cylinder, a diaphragm and a valve seat, the pneumatic cylinder being divided into a pneumatic chamber and a spring chamber by a piston, a spring being disposed in the spring chamber, the pneumatic chamber and the spring chamber each having a breathing hole, the breathing hole of the pneumatic chamber having an inner accommodating chamber, the buffer valve being mounted to the inner accommodating chamber, the buffer valve being provided with a gas connector for filling a high-pressure gas, the buffer valve being configured to adjust a flow rate of the breathing hole, the buffer valve being used for adjusting release of the high-pressure gas in the pneumatic chamber without affecting a filling speed of the high-pressure gas in the pneumatic chamber, a tool part being disposed on an outside of the buffer valve for mounting or demounting the buffer valve and for mounting the gas connector;
- the diaphragm being an integral structure and having a circumferential portion, a central portion and an elastic portion, the elastic portion having a Q-shaped cross section with an arc-shaped curve;
- characterized in that:
- in the process from an open state to a closed state for a normally closed valve and in the process from the closed state to the open state for a normally open valve, when the high-pressure gas is released, the buffer valve can slow down a pressure shock wave generated by the release of the high-pressure gas within a period of time, and the compressed spring in the spring chamber is restricted to slowly release its elastic force during expansion;
- an approach speed of the central portion of the diaphragm of the normally closed valve toward the valve seat is reduced to reduce impact and to reduce jet flow generated by the valve seat when it is closed;
- an instantaneous leaving speed of the central portion of the diaphragm of the normally open valve away from the valve seat is reduced to slow down generation of local negative pressure and reduce generation of eddy flow and turbulent flow;
- an inner flow channel of the buffer valve includes an inner gas hole, an inner chamber, an outer gas hole, and a floating ball;
- the inner flow channel is selectively in communication with the internal pneumatic chamber or the gas connector of an external high-pressure gas source;
- the inner chamber has an axis, an inner annular surface, an inner end and an outer end, the inner end communicates with the pneumatic chamber through the inner gas hole, the inner gas hole is disposed at a position deviating from the axis of the inner chamber and proximate to the inner annular surface, the outer end of the inner chamber communicates with the gas connector through the outer gas hole, the outer gas hole is located on the axis of the inner chamber, the floating ball is disposed in the inner chamber and floats along with the high-pressure gas, the floating ball having an outer diameter d1 less than an inner diameter D2 of the inner chamber, d1<D2;
- the buffer valve has the following functions in operation, including a high-filling action, a shielding action, a releasing action, including a releasing mechanism, a shielding time Δt, and an adjusting mechanism;
- the high-filling action is that when the pneumatic chamber is filled with the high-pressure gas, the high-pressure gas enters the inner chamber through the outer gas hole from a high-pressure pipeline and pushes the floating ball to move toward the inner gas hole, without covering the inner gas hole, allowing the high-pressure gas to enter the pneumatic chamber to have the high-filling action;
- the shielding action is that when the high-pressure gas is released from the pneumatic chamber, the high-pressure gas passes through the inner gas hole to enter the inner chamber and drives the floating ball to move toward the outer gas hole to cover the outer gas hole to slow down the release of high-pressure gas;
- the shielding action is caused by an opening of the floating ball and an inner diameter d3 of the outer gas hole to form a circular contact line C, the circular contact line C cannot achieve an airtightness effect but reduces the speed of gas leakage;
- the shielding action is caused by a pressure difference ΔP between a gas pressure and a pipeline pressure to generate a pressing force Fp on the floating ball, the pressing force Fp is equal to the pressure difference ΔP multiplied by a circular area of the circular contact line C;
- the releasing action is that when the high-pressure gas is continuously released under the shielding action, after the gas pressure is reduced, the releasing action is to release the pressing force Fp through the releasing mechanism, so that the floating ball is displaced and no longer covers the outer gas hole, and the residual high-pressure gas is discharged quickly;
- the releasing mechanism is a mechanism using at least one of a weight W of the floating ball, an elastic force Fs and a magnetic force Fm to resist the pressing force Fp and move the floating ball to complete the releasing action;
- the shielding time Δt is a period from the generation of the shielding action to the completion of the releasing action;
- the adjusting mechanism is that the length of the shielding time Δt is adjusted through the releasing mechanism of the releasing action.