TH35409A - Diaphragm valve - Google Patents

Abstract

DC60 (04/08/40) Diaphragm valves for pumping water in irrigation systems or similar applications consist of a hollow valve body with an inlet for hydraulic or pneumatic connections and at least one ventilation opening allowing fluid to pass through the side walls of the valve body from the outside to the inside. A movable diaphragm is mounted inside the valve body and normally closes this vent opening. A cavity is located behind the diaphragm and has a bleed aperture allowing fluid to pass through the diaphragm from this aperture to the cavity behind the diaphragm. When the pressure in the diaphragm vent opening is lower than the external pressure, the diaphragm moves away from the inlet opening to allow fluid to enter the valve body through the side walls and then moves to close the vent opening when the pressure on the diaphragm vent opening is reduced. To equalize the pressure with the external pressure, a diaphragm is typically required. This diaphragm consists of a thin, flexible annular skirt extending from the outer surface of the diaphragm, with the skirt's edge retained in an annular recess around a cavity behind the diaphragm. This allows the diaphragm to move to the inside of the valve body, thus enabling movement by bending and/or folding the skirt. Diaphragm valves for pumping water in irrigation systems or similar applications consist of a hollow body with a port for hydraulic or pneumatic connections and at least one ventilation opening. A vent passes through the side or wall of the valve body from the outside to the inside. The movable diaphragm is mounted inside the valve body, usually closing this vent opening, and a cavity is located behind the diaphragm. A bleed aperture allows fluid to pass through the diaphragm from this opening into the cavity behind the diaphragm. When the pressure in the diaphragm's lateral channel is lower than the external pressure, the diaphragm moves away from the inlet channel to open a passage for fluid to enter the valve body, pass through the side walls, and then closes the bleed aperture when the pressure in the diaphragm's lateral channel equalizes with the external pressure. Often, the diaphragm is required to include a thin, flexible annular skirt extending from the outer surface of the diaphragm, with the end edge retained in an annular recess around the cavity behind the diaphragm to connect the diaphragm to the valve body, allowing for movement. Thus, the diaphragm moves by bending and/or folding the skirt.

Claims (9)

1. A diaphragm valve consists of a hollow valve body with an outlet port for connecting a hydraulic or pneumatic system to the valve body and at least one inlet port. A movable diaphragm is mounted inside the valve body and normally closes the outlet port. A cavity is located behind the diaphragm and has a bleed aperture, allowing fluid to pass through the diaphragm from the outlet port to the cavity behind the diaphragm. In this configuration, when the pressure on the diaphragm outlet side is lower than the pressure on the diaphragm inlet side, the diaphragm moves away from the outlet port to open the inlet port, allowing fluid to enter the valve body. It then moves back to close the outlet port when the pressure on the diaphragm outlet side equals the pressure on the diaphragm inlet side. 2. Diaphragm valve according to claim 1, where the diaphragm consists of a thin, flexible annular skirt protruding from the outer surface of the diaphragm, with the end edge of the skirt retained in an annular recess around the cavity behind the diaphragm to allow the diaphragm to move to the inside of the valve body; thus the diaphragm moves by bending and/or folding the skirt. 3. Diaphragm valves under claim 2 where the edge is integrated into the major part of the diaphragm body by injection molding of the plastic material. 4. Diaphragm valve according to claim 3, in which the hollow valve body comprises the main valve body and cover components, and an annular groove is made within the surface of the cover, thus the gap behind the diaphragm is defined between the inner surface of the cover and the diaphragm. 5. The diaphragm valve under claim 4, where the guiding unit extends from the central direction from the inner surface of the end cap through the outlet hole through the diaphragm. 6. A diaphragm valve as described in claims 1 through 5 in which the inlet contains at least one ventilation opening that passes through the side wall or the wall of the valve body from the outside to the inside of the valve. 7. A diaphragm valve consists of a hollow valve body with a port for connecting a hydraulic or pneumatic system to the valve body, and at least one ventilation opening allowing fluid to pass through the side wall or the valve body from the outside to the inside. A movable diaphragm is mounted inside the valve body and is usually closed to this port. A cavity is located behind the diaphragm, and a bleed aperture allows fluid to pass through the diaphragm from this cavity to the cavity behind the diaphragm. In this configuration, when the pressure in the diaphragm's lateral channel is lower than the external pressure, the diaphragm moves out of the channel to open a port, allowing fluid to enter the valve body through the bleed opening and through the side wall. It then moves back to close the bleed aperture when the pressure in the diaphragm's lateral channel is equal to the external pressure. 8. The diaphragm valve is similar to that shown in Figures 1 to 3 and is described here. 9. The diaphragm valve is similar to that shown in Figure 4 and is described here (Clause 9, 2 pages, 4 figures).