Rubber soft joint widely serves in civil building water supply, sewage treatment pipeline, etc. Besides, it is ideal for liquid or gas deliver, petroleum, ship, etc.

In pipeline system, there are many types of rubber soft joints. While the size of rubber soft joints is usually expressed by the pipe outer diameter D and the pipe inner diameter d. Due to various uses, you need a variety of rubber soft joint accessories. Such as valve, flange, etc. In this way, the diameters of pipes and parts are quite large. Thus it is difficult to produce, design and construction. In order to sell in batches and reduce costs and improve efficiency, it must be standardized. While the nominal diameter is an important part.

rubber soft joint

The so called nominal diameter is the common diameter of various rubber soft joints. It is a standard artificially specified for the convenience of design, manufacturing and maintenance. Rubber soft joint wholesalers are also compared to the nominal diameter. And it is the spec name of the flexible pipe. Nominal diameter is represented by the symbol DN. 

In general, the diameter of rubber soft joints can be outer diameter, inner diameter and nominal diameter. The outer diameter is represented by the letter D. Then follows the wall thickness. For example, a hose joint with an outer diameter of 108mm and a wall thickness of 5mm is represented by DN108*5.