Inner coating can greatly improve pipeline capacity. It can prevent corrosion and reduce the role of the pumping costs. Improving gas flow within the coating technology development update has become the main methods of transport in major companies to increase the amount. It can significantly reduce the friction between the gas and the tube wall which is the basic function of the inner coating technology. The friction caused by the tube at the factory of its inner surface is rough, the use of the inner pipe wall coating becomes smooth, the friction between the gas and the wall becomes small. It will accelerate the gas flow rate, and the cost of pumping the respective compression lower. 

The coating into a file (dry film thickness of 80 ~130 um) coated on the inner wall of the tube. Epoxy resins are currently the most widely used in the coating material, a lot of in-service pipeline are in use. The inner coating should have a certain adhesion, porosity, elasticity, chemical resistance and corrosion resistance, and the ability hardness and resistance to pressure variations should reach a certain level. Quality epoxy resin coating on international standards to meet or exceed the requirements of API and ISO.

A typical inner coating comprises two components: a resin, which served as the basis for the role, two for epoxy curing agent, from the " curing" and "activation" role. The two components were tested liquid, respectively filling, use, or both will be mixed before use. After mixing, typically using a two-component spray equipment to be coated pipe. Regular manufacturers in the coating will be mixed according to a certain percentage ratio. The coating does not require preheating, but be careful to choose the right nozzle, the nozzle diameter and spraying pressure should comply with regulatory requirements. Nozzles are mounted at the end of the lance tube is rotated, the lance activities from one end to the other end of tube is coated work. Spraying process is regulated, the regulation has been available for a wet film thickness of 200 ~ 220um. Adjusted by the following four ways: 
1. adjusting the boom travel speed
2. to adjust the rotation of the tube
3. adjusting the distance between the nozzle and the tube surface
4. adjust the spray pressure.