By transmission medium, working steel tube, foam insulation layer, polyethylene plastic outer protecting pipe, through the device sequentially outward together.

The first layer : the work of pipe layer

According to the design and customer requirements general selection of seamless tube spiral pipe ( GB8163-87 ) ( GB9711-88; SY/T5038-92 ) and longitudinal welded pipe

( GB3092-93 ). Steel surface after advanced Shotblast derusting process, steel pipe derusting grade up to standard in GB8923-1988 Sa2

, surface roughness of up to GB6060.5-88 standard R=12.5 micron.

Second layer: polyurethane insulation layer

Use of high pressure foaming machine in the steel pipe in the outer layer cavity formed between the disposable injection liquid and rigid polyurethane foam. Commonly known as

The " pipe in pipe blowing process ". Its action is waterproof, two insulation, three supporting net weight. When the transmission medium temperature : -50 ℃-

At 120 ℃, made of hard polyurethane urea acid ester foam heat insulation layer.

Third: high density polyethylene protection layer

Preformed into a certain wall thickness black ( yellow ) plastic pipe, whose function is to protect the polyurethane insulation layer from mechanical damage is hard, two

Waterproof anti-corrosion.

Parameter specification:

Outer diameter mm 238 mm wall thickness of 3.5 weight Kg 2.475 error of mm± 0.28 mm 159 corresponding outer diameter of steel tube

The corresponding insulating layer thickness of 37 mm 245 mm corresponding sleeves

Characteristic.

1, reduce project cost. 2, low thermal loss, energy saving. 3, anti-corrosion, insulation performance, long service life.

In 4, covers an area of small, fast construction, environment protection.