Connection between Flange and Water Pump

A flange is a disc-shaped component, most commonly used in pipeline engineering, and is always used in pairs. In pipeline engineering, flanges are mainly used for pipe connection.

On pipes to be connected, a flange is installed on each end. Screwed flanges can be used for low-pressure pipelines, while welded flanges are used for pressures above 4 bar.

A sealing gasket is placed between the two flanges, which are then fastened with bolts. Flanges of different pressure ratings have different thicknesses and use different bolts.

When pumps and valves are connected to pipelines, the corresponding parts of these equipment are also made into flanged shapes, which are also referred to as flange connections.

Any connecting part that uses bolts around its perimeter to join and seal two parallel surfaces is generally called a "flange". For example, connections in ventilation ducts can be referred to as "flange-type parts".

However, such a connection is only part of a piece of equipment. For instance, in the connection between a flange and a pump, the pump itself should not be called a flange-type part.

Smaller components such as valves may be referred to as flange-type parts.

A gasket is a ring made of material that can undergo plastic deformation and has a certain strength.
Most gaskets are cut from non-metallic sheets or manufactured to specified dimensions by specialized factories, using materials such as asbestos rubber sheets, asbestos sheets, polyethylene sheets, etc.

There are also metal-jacketed gaskets made by wrapping non-metallic materials such as asbestos with thin metal sheets (tinplate, stainless steel).

Another type is the spiral-wound gasket, made by winding thin steel strips and asbestos strips together.

Ordinary rubber gaskets are suitable for applications below 120°C. Asbestos rubber gaskets are suitable for steam service below 450°C, oil service below 350°C, and pressure below 5 MPa. For general corrosive media, acid-resistant asbestos sheets are most commonly used.

In high-pressure equipment and pipelines, lens-type or other shaped metallic gaskets made of copper, aluminum, 10# steel, or stainless steel are used.

The contact width between high-pressure gaskets and sealing surfaces is very narrow (line contact), and the sealing surfaces and gaskets require high machining finish.

Screwed flanges are used for low-pressure, small-diameter applications, while welded flanges are used for both high-pressure and low-pressure large-diameter applications. Flanges of different pressure ratings differ in thickness, as well as in the diameter and quantity of connecting bolts.