What are the connection methods of plastic-coated steel pipes

1. plastic-coated steel pipe cutting

metal saws should be used for cutting plastic-coated steel pipes, and sawing machines should be used for large-diameter pipes. when using entrenched cutting, the speed should not exceed 800r/min; the section of the pipe to be cut should be perpendicular to the pipe axis.

2. preparation before connection of plastic-coated steel pipes

a. after cutting the pipe port, the metal burrs should be trimmed with a fine file.

b. plastic-coated steel pipes should use a special reamer to chamfer 1/2 the thickness of the plastic-coated layer, and the slope of the chamfer should be 10°-15°.

c. if the plastic-coated steel coating is intact at the port, it should be cut into a chamfer with a sharpener; if the port is damaged, it must be repaired (with repairing fluid), until the coating is as a whole without cracks.

d. after grooving, the plastic coating layer on the protruding part of the groove will be damaged and must be repaired until the surface of the coating is smooth and there are no cracks or damaged points as a whole.

e. cleaning and processing should use cotton scraps and brushes to remove oil, water, and metal cutting from the pipe end and inside the pipe.

connection method

a. thread connection: automatic threading machine should be used for threading, and the current national standard should be implemented.

b. flange connection:

one-time installation method: on-site measurement and drawing of pipeline single-line processing diagrams, after processing, coating, and plastic lining, it can be transported to the site for installation.

secondary installation method: use non-coated and plastic-lined steel pipes and fittings on site, weld flanges, assemble pipes, and then disassemble them for coating and plastic-lined processing, and then transport them to the site for installation.

c. groove connection: the finished grooved plastic-coated pipe fittings should be used first; the groove should be pressed by a special rolling groove machine, and the groove depth should meet the relevant standards.