Design and principle of operation of the reverse flanged gate

Flanged hydraulic valves are characterized by increased sealing capabilities of the joints, and therefore are more often used as pipe fittings on hydraulic networks with increased pressure of the working medium. They are less compact than threaded ones, so they require more space for installation and for subsequent maintenance.

Device and features of the action

The principle of operation of the reverse flange gate provides for the possibility of moving the working fluid in only one direction, while the flow reversal is automatically blocked.

The device consists of the following parts:

• Housing having a flat flange (sometimes – welded);
• Saddles;
• Rotary disc;
• Covers;
• Seals – seats and flanges.

Depending on the values of pressure and density of the pumped working medium, the flanged reverse hydraulic seal can open or block the seat. The inner disc allows fluid to flow forward, which causes the valve to open. Then the flow is reversed, closing the valve. The tightness of the flange joints is ensured by seals.

Varieties of construction

In practice , the following types of reverse flanged valves are used:

• Rotary;
• Two - disc;
• With a reduced noise level;
• For injectors;
• Ball bearings;
• Inclined.

The most modern design from this list is considered to be a silent check valve. It is a hydraulic distribution device equipped with a spring with a central direction of the double rod to the end surface of the polished seat, which is provided by means of a special guide sleeve. Such a design ensures the movement of the rotary disc without jerks and pops, and in a wide range of liquids, as well as combinations of pressure and pumping temperature of the working medium.

Standard body materials are grey cast iron, carbon or stainless steel, nickel-aluminum bronze, red brass.

Reverse flanged valves can be equipped with an additional flange for subsequent butt welding, as well as a gasket made of a corrosion-resistant alloy with a low coefficient of thermal expansion (for example, inconel). This design is used for high-pressure industrial pipelines.

The devices can be installed in vertical or horizontal positions. Before sale, they are subject to mandatory calibration, which is performed at the manufacturer of the products.

All described designs of hydraulic valves must comply with the technical requirements of GOST 27477-87.