The sealing gasket of plate heat exchanger is one of the important components of plate heat exchanger. It is a ring made of materials that cause plastic deformation and have certain strength. Most gaskets are cut from non-metallic plates, or made by professional factories such as asbestos rubber plate, asbestos plate, polyethylene plate, etc. with specified dimensions. There are also metal-clad gaskets made of non-metallic materials such as asbestos wrapped with thin metal plates (white iron plate, stainless steel). There is also a spiral wound gasket made of thin steel plate and asbestos rope.

The sealing gasket of ordinary rubber plate heat exchanger is applicable to the temperature below 120. When the water vapor temperature is lower than 450, the oil temperature is lower than 350, and the pressure is lower than 5MPa, the acid-resistant asbestos board is commonly used in general corrosive media. Lens type or other metal gaskets made of copper aluminum 10 # steel and stainless steel are used in high-pressure equipment and pipelines. The contact width between the high-pressure gasket and the sealing surface is very narrow (line contact), and the sealing surface has a high machining finish.

Structural characteristics of sealing gasket of plate heat exchanger
The plate type of plate heat exchanger is divided into one-way flow and diagonal flow according to the flow form of heat exchange medium, so the sealing gasket of plate heat exchanger is divided into one-way flow and diagonal flow according to the flow form of heat exchange medium.
One-way flow refers to the heat transfer medium flowing out of the right edge hole of the heat exchange plate and then flowing out of the right edge hole. Similarly, the heat transfer medium flowing out of the left corner hole then flows out of the left corner hole. Diagonal flow refers to the flow of heat exchange fluid from the right corner hole, from the left corner hole, or from the right corner hole, indicating diagonal flow. From the perspective of heat exchange efficiency, diagonal flow mode is better than unilateral flow mode, but the cost of using unilateral flow mode is relatively low, so unilateral flow mode is generally used when the heat exchange efficiency can be met.
The sealing gasket of plate heat exchanger can be divided into three types according to the installation method on the heat exchange plate
(1) Direct pasting is to apply sealant on the sealed gasket and directly paste it into the installation groove of the heat exchange plate.
(2) Adhesive type, that is, design the assembly hole on the heat exchange plate, design the rubber nail on the edge of the sealing gasket, insert it into the installation slot, and then nail it into the adhesive hole.
(3) The buckle type is designed with a buckle on the side of the sealing gasket, which is used to buckle the sealing gasket onto the heat exchange plate.
Among the above three methods, the sealing gasket of plate heat exchanger has simple structure and easy processing, but it is difficult to install and disassemble. The structure of inlay and buckle gasket is complex and complicated, but the installation and disassembly are relatively easy. The sealing gasket of plate heat exchanger can be divided into symmetrical type and asymmetrical type according to the sectional shape of the product. The symmetrical type is generally applicable to the plate with diagonal flow. The upper and lower sealing surfaces are plane type, symmetrical along the water plane, and can be installed in the opposite direction.