What does the color of the outer ring of a spiral wound gasket mean?

GBT 4622.1-2022--Wound gaskets for pipe flanges Part 2: Please refer to the PN series

The color of the outer ring of a spiral wound gasket does not have a fixed or standard meaning. Different manufacturers and different applications may have different marking methods. Generally speaking, color may be used to differentiate between spiral wound gaskets of different materials, sizes or functions. For example, green might represent a special material or compression property, yellow might represent another material or gauge, and a metallic base color might represent another special use. It is recommended that you conduct further inquiries and understanding with the supplier or manufacturer to ensure correct use and understanding of the color identification of the outer ring of the spiral wound gasket. .

Few domestic gasket manufacturers use color for identification, but foreign manufacturers all use appearance color identification. For example, this manufacturer.

There is no clear rule on which color should be used for marking, but it is relatively clear that types C and D are marked with a steel seal because they have an alignment ring. Generally, the standard number, PN, DN, and material code are marked. Of course, you can also paint the outer circumference of the alignment ring with color to quickly identify which specification and material it is. The end surface cannot be painted, which will affect the sealing performance. For type A, which is the basic type, there is only one winding circle. There is no way to stamp it, and a label must be hung as a mark. Of course, coloring is used as a means of auxiliary identification. The same is true for type B with an inner ring. The inner ring is relatively narrow, and there is no way to stamp it. Therefore, the basic type A and the inner ring type B need to be marked with labels. You can also choose to paint the outer circumference with color. This is an auxiliary hand. Section, as for how to select the type, there is no way to align the basic type A and the inner ring type B. They can only be aligned by inlaying. In this case, they are suitable for sealing surface methods with sealing surface positioning grooves, such as tongue and groove surface combinations, concave and convex surface combinations. Types C and D with positioning rings are suitable for flanges with raised surface seals. The raised surface means protruding. There is no such term for the convex surface. The convex surface cannot be headed and can only be a concave and convex surface. The raised surface flange is easy to deviate when installed, so the centering ring must be positioned when selecting. In addition, the centering ring also acts as a tightening limiter to prevent the winding ring from spreading out after being stressed. At this time, some students will ask, what to do if there is no centering ring? As mentioned before, Type A and Type B are suitable for inlay sealing, such as tongue and groove and concave and convex surfaces. There will be an outer groove structure or internal pressure to limit the winding coil from spreading.

The standard stipulates a reference coloring scheme, which appears as an option, so it is not clearly stipulated. This is clarified to avoid misleading or causing disagreement, but in view of the differences between different manufacturers.* Depending on your habits, and the number of order types, sometimes you don’t need it, and sometimes you need markings, but in the end, stamps and labels should be the main ones, and color is only used as an auxiliary means.

There are various materials supplied in the same batch. The manufacturer separates them and does not mix them, just paint them with different colors. When we are doing the project and placing the order, we ask the manufacturer to put the laser mark on it.