Description

Hydro-Pneumatic Pressure Switch (QKY21-15 QKY21-25)

1 Overview
The liquid-gas switch is a two-position two-way reversing valve, which controls the start and stop of the pneumatic oil pump.
2. Main technical parameters
Model:QKY21-25 QKY21-15

Opening pressure:17.85Mpa(2580psi)
Closing pressure:21Mpa(3000psi)
Weight:7.8kg(17.2lb)
3. Structure and working principle
The main components of QKY21-25 liquid-gas switch include:
Connecting flange, gasket, compression sleeve, nameplate, sealing seat, gasket, vent joint, lock nut, supporting nut, supporting core sleeve, connecting sleeve, core rod, spring, supporting sleeve, retaining ring, valve seat, O-shaped Seal ring.
The NPT3/4 interface of the valve seat is connected to the accumulator oil circuit, the NPT1 interface of the connecting flange is connected to the pneumatic pump, and the NPT1 interface of the connector is connected to the air source. The accumulator oil pressure acts on the core rod. When the hydraulic oil pressure drops to 17.85Mpa, the hydraulic pressure acting on the core rod is less than the spring force, and the core rod, the sealing seat and the gasket move upward together under the action of the spring force. , At the same time connect the air circuit, the compressed air enters the pneumatic oil pump through the vent connector and makes it work. The pressure oil discharged by the pneumatic oil pump enters the system. When the system pressure rises to 21MPa (3000psi), the hydraulic pressure acting on the core rod is greater than the spring force to move the core rod downwards, and the air circuit is closed at the same time. The compressed air cannot enter through the ventilation joint The pneumatic oil pump, the pneumatic oil pump stops working.
4. Instructions for use
The adjustment method of setting pressure is to insert a round steel rod into the round hole of the lock nut, unscrew the lock nut, and then insert the steel rod into the round hole of the back nut, rotate clockwise, the spring compresses, the tension increases, and the closing oil pressure increases ; Rotate counterclockwise, the spring stretches, the tension is weakened, and the closing oil pressure decreases.
The oil pressure adjustment and calibration of the liquid-gas switch should be carried out when the air pump is running. Generally, it has been adjusted before leaving the factory, and there is generally no need to adjust it when used on site. However, after long-term use, the shut-off oil pressure will decrease, which can be adjusted as appropriate.