The plunger valve is composed of the valve body, the valve cover, the valve stem, the plunger, the hole frame, the seal ring and the handwheel. When the handwheel is rotated, the valve is opened and closed by the valve rod driving the plunger up and down in the middle of the hole frame. In the valve plunger and the seal ring used between the interference fit, by adjusting the gland in the flange bolts, the sealing ring and the body side force generated by the compression of the cylindrical hole surface and the plunger seal, thus ensuring the sealing performance of the valve, eliminate internal and external leakage, while the valve opening force is small, can realize the quick opening valve on and off. Compared with cut-off valve, the plunger valve has long life and labor-saving operation. But the adjustment stroke is longer than the cut-off valve, so the throttle control is more difficult than the cut-off valve. Both are unsuitable for places with clear requirements.

Plunger valve is closed by a stainless steel plunger, two elastic sealing ring and a metal frame, the sealing effect by the plunger and the seal ring is closely fitted to the plunger, inserted in the two sealing ring, the sealing area is far greater than the ordinary valve; switch plunger valve, the piston moves slowly in the ring in the contact surface almost does not wear off when the plunger is inserted into the lower sealing ring, truncated channel; open, although from the plunger seal, but still hiding in the ring, remain isolated from the outside, not to leak.

Because the surface of the plunger is processed by a high precision outer grinding machine. Sealing ring is a new type of non-toxic new sealing material with high elasticity and high wear resistance, so the seal is reliable and durable. Thus the service life of the plunger valve is improved.