Forever Exclusive patented product - Polyethylene Composite tape Coating

2023,12,10

Specification for Polyethylene Composite tape Coating for

Induction Bends ofOil & Gas Storage and Transportation Project

Hot bending pipe, also known as medium frequency pipe, its production process belongs to the scope of thermal expansion.After the straight pipe is cut off, an induction ring is placed on the part of the steel pipe to be bent by a bending and pushing machine. The pipe head is clamped by a mechanical rotating arm, and a medium frequency current is introduced into the induction ring to heat the steel pipe. When the temperature of the steel pipe rises to the plastic state, mechanical thrust is used to push it forward at the rear end of the steel pipe for bending. The bent steel pipe is quickly cooled with coolant, which heats, advances, bends, and cools it at the same time, Continuously bend the bent pipe. Hot bending pipes are mainly used in various industries such as building circular steel structures, tunnel supports, roof beams, subway engineering, aluminum doors and windows, ceilings, cylindrical inner frames, balcony handrails, shower room doors, production line tracks, fitness equipment, etc.

Exclusive patented product - polyethylene composite tape

General anti-corrosion requirements for hot bending pipes Polyethylene composite tape anti-corrosion coating for room temperature and/or high temperature hot bending pipes that meet the construction requirements of -30 ℃ or above and the maximum design temperature not exceeding 60 ℃ as required by this technical specification, and/or the maximum design temperature not exceeding 80 ℃.

The bottom layer of the polyethylene composite tape anti-corrosion layer should be a fusion bonded epoxy powder spraying layer, and the outer layer should be wrapped with polyethylene composite tape Layer. The specification of the composite tape should be selected based on the pipe diameter, and the winding overlap of the composite tape should be greater than 50%. The minimum thickness of the composite tape anti-corrosion layer is 1.7mm. The thickness of the anti-corrosion layer at the weld seam should not be less than 2.3mm

1.Coating of anti-corrosion layer

The surface pre-treatment of bent pipes should use clean, oil-free, pollution-free, and dry abrasives. The particle size should be able to produce the required surface anchor depth and cleanliness. After sandblasting and rust removal, the salt content on the surface of bent pipes should be tested according to the methods specified in GB/T 18570.9 or other suitable methods. The salt content on the surface of bent pipes should not exceed 20mg/m2.

The winding of polyethylene composite tape should meet the following requirements:
1) Polyethylene composite tape should be mechanically wound continuously, preheated, and continuously sprayed with fusion bonded epoxy powder Entanglement.

2) When winding composite tapes, the adhesive layer of the polyethylene composite tape should be separated from the epoxy powder coating and the polyethylene composite tape layer Tight adhesion. Polyethylene composite tape should be wrapped under a determined mechanical tensile tension to ensure axial overlapPart of the polyethylene composite tape and both sides of the weld are tightly bonded, and the number of overlapping layers at the inner arc position should not exceed 3Layer.

3) During the winding process, it is advisable to use both circumferential rolling (during winding) and axial rolling (at the weld seam) processes Ensure that the polyethylene composite tape is overlapped in the circumferential direction and there is no hollowing on both sides of the weld seam. Avoid damaging the polyethylene during rolling Ethylene composite tape anti-corrosion coating surface.

4) After winding the polyethylene composite tape, it is advisable to use infrared or other heating equipment to apply the overall anti-corrosion coating of the composite tape

Heating, heating time and temperature should meet the range specified in the process specifications, and the composite tape adhesive layer should be completely melted Rong; Surface temperature should be monitored during the painting process.

After the coating of the polyethylene composite tape anti-corrosion layer on the hot bend pipe, it should be cooled according to the time interval determined by the process specification, until the surface temperature does not exceed 60 ℃; After the completion of the coating of the polyethylene composite tape anti-corrosion layer, mechanical polishing should be used to remove the polyethylene layer at the pipe end. The reserved length at the end of the hot bending pipe should be 100mm~150mm, and the end face of the polyethylene composite tape layer should form a chamfer of no more than 30 °; A 10mm to 30mm epoxy powder coating should be retained outside the end of the polyethylene composite tape layer. When fully automatic welding or ultrasonic testing is used for the weld seam at the mouth of the hot bending pipe, the length of the reserved non anti-corrosion layer at the end of the hot bending pipe shall not be less than 130mm;

Polyethylene composite tape

Polyethylene composite tape is not like 2PE Heat Shrink Tape, also not 3LPE Heat Shrink Sleeves, 3LPP Wrap Around Sleeve, Cold Applied Tape, Polyethylene composite tape is completely equivalent to 3LPE coating in terms of temperature, appearance, and performance,is special for 3LPE Hot bending pipe.

Coating

Author:

Ms. Tao

E-mail:

forever@caepforever.com

Phone/WhatsApp:

++86 19182078675