Pressure reducing valves with multiple heads and seats

摘要

The present invention provides a pressure reducing valve. The pressure reduction valve includes a main body, an inlet, an outlet, a stem, a main seat, a pilot diaphragm, a main head, and a control spring. The pressure reduction valve includes additional auxiliary seats with corresponding auxiliary heads and displacement members/surfaces. The pressure reduction valve additional includes auxiliary seats with corresponding auxiliary heads and displacement members/surfaces enables stage wise opening of the secondary seats and the main seat. This enables to meet highly varying media flow demands using single pressure reduction valve, having less hunting effect and eliminating use of multiple pressure reduction valves.

主权项

1. A pressure reduction valve comprising:
a body; an inlet and an outlet for media; a stem secured to a main diaphragm; a main head secured to the stem; a main seat for disposing the main head thereon for closing and opening the flow of media therethrough; a control spring for adjusting pressure for opening the main head; a first spring disposed over the main head to resist the movement thereof; a pilot diaphragm to act against the control spring pressure; and a sensing pipe for connecting the main diaphragm to the pilot diaphragm; characterized in that the pressure reduction valve comprises: a first displacement surface configured on the stem for lifting the main head thereof; a plurality of openings configured on the first displacement surface for passage of media therethrough; a first auxiliary seat configured on the main head; a first auxiliary head adapted to cover and uncover the first auxiliary seat to close and open the media flow therethrough; a second spring disposed over the first auxiliary head to resist the movement thereof; a second displacement surface configured on the stem for lifting the first auxiliary head; a second auxiliary seat configured on the first auxiliary head, a second auxiliary head adapted to cover and uncover the second auxiliary seat to close and open the media flow therethrough; and a third spring disposed over the second auxiliary head to resist the movement thereof; wherein in a closed condition the distance between the first displacement surface and the main seat is more than distance between the second displacement surface and the first auxiliary head, and wherein lifting of the stem by the main diaphragm initially causes lifting of the second auxiliary head, followed by lifting of the first auxiliary head, and then lifting of the main head.