Lixin fittings that four kinds of practices polyurethane insulation pipe fittings:

  (1) Quick connectors Steel Sleeve

Molding sleeves, coated with anti-corrosion paint with steel in the factory, and additional zinc steel block (sacrificial anode method) as a supplementary corrosion protection of steel sleeves. It is divided into two different diameters or three in the field with specialized methods for rapid clip. To close, the Secretary sleeves with polyurethane insulation pipeline. Gap between the wafer surface into a dedicated seal. This method requires air tightness test.

Scope This method is φ50 ~ φ450 mm. The advantage is the factory than the production, construction convenient, solid structure. Strong reliability, according to foreign introduce up to 50 years. But more expensive.

(2) electric ring coupling sleeves (Swedish)

PE jacket factory will join copper pipe flaring at both ends of the resistor ring, in the field with a special heat resistance welding process control loop, so that the outer sleeve (sleeve) with polyurethane insulation shell tightly integrated into a whole.

This method uses a range of polyurethane insulation polyurethane φ80 ~ φ800mm tube. Construction is simple, fast, tight, good quality and easy assured characteristics. Prices are moderate, but the interface has raised phenomenon. This method Sweden, Norway widespread use.

(3) pre-heating copper mesh coupling sleeves

   Intensive copper wire embedded in the ring coupling sleeves (at the factory) in the field welder power transmission program controlled electric heating plastic, so sleeves with polyurethane insulation shell fused into one.

   Scope This method is φ125 ~ φ600 mm, as is the skill to operate computer-controlled unmanned factors, so the quality is guaranteed. Currently in Germany, Denmark, the use of a wide range.

  (4) heat-shrinkable sleeves coupled with polyurethane insulation with the same material as the outer casing pipe (sleeves with special seals heated to shrink. Tightness test was no problem, and then both ends of the heat-shrinkable sleeve, heat to 150 ℃, the shrink sleeve automatically shrink and dry knot firmly in polyurethane insulation shell and tube coupling sleeves. contraction apply to cross-linked polyethylene outer layer and the base material butyl rubber inner layer dissolving pulp.

   According to Fong fittings noted, this method owing to double-sealed, waterproof performance is better for the river and through the high water table areas. The price is relatively low. However, due to the high technical requirements of the operation, to be specially trained and experienced staff to operate in order to ensure quality. One applies polyurethane insulation smaller diameter pipe joint.