First, high-performance PTFE powder is used to push (extrude) into a pipe, and the surface is chemically treated. Then, it is lined into a seamless steel pipe (the outer diameter of the lining pipe is slightly larger than the inner diameter of the steel pipe by 1.5-2mm) to form a tight lining without gaps. In order to eliminate the stress, it is placed in the furnace and heated to 180℃ for constant temperature treatment, so that it can be used at a temperature below 180℃. At the same time, the axial tensile strength of the push (squeeze) tube is obviously better than that of the winding tube, and it can be used in the micro negative pressure pipeline.

Test, inspection and application scope of PTFE lining layer:

1. All pipes and pipe fittings shall be subject to hydrostatic test at 1.5 times the design pressure.

2. All PTFE lining layers involved shall be subject to 100% integrity inspection after hydrostatic test, and the leakage point inspection method shall be electric spark test.

3. Usage specification

a. Nominal diameter: DN25 ~ DN300

b. Fabrication length: ≤4000mm

c. Applicable temperature: -20~200℃

d. Applicable medium: it can transport any concentration of strong acid, strong alkali, organic solvent, strong oxidant, toxic, volatile and flammable chemical medium.