According to its different outer protective layer, polyurethane insulation steel pipe can be divided into Fiberglass reinforced plastic (FRP) insulation pipe, high-density polyethylene insulation pipe, ordinary polyurethane insulation pipe and other outer protective layer insulation pipe. FRP insulation pipe is generally composed of fiberglass outer protective layer, rigid polyurethane foam plastic insulation layer and internal steel pipe. The FRP layer or resin layer with 90% content and thickness of 1.55-2.5mm effectively solves the problems of insulation, sliding lubrication and waterproof of exposed pipe end of pre-fabricated directly buried insulation pipe for high temperature heating at 130 ℃-600 ℃.
The structure of Inner steel pipes
Carrier pipe (inner pipe) According to the design and customer requirements, seamless steel pipe, LSAW pipe and SSAW pipe can be the best choice for the carrier pipe of pre-insulated steel pipe. The material can be:
API 5L Gr. B X42 X46 X52 X56 X60.
ASTM A106/53 Gr. A /Gr. B / Gr. C
APL 5CT:J55, K55, N80, L80, C90, T95, P110
DIN 1629: St 37.0, St 44.0, St 52.0
DIN 17175: St35.8, St45.8, 17Mn4, 17Mn5, 15Mn5, 15Mo3, 13CrMo910
EN10240: S235JO, S235JR, S355JR, P265TR1, S355JRH...
(Other material manufactured by Customer’s Demand)
Insulation Materials Layer
Rigid polyurethane foam is injected into the cavity between the steel tube and the outer layer by high-pressure foaming machine. Polyurethane foam has good mechanical and adiabatic properties and can withstand high temperature to 120℃. It can withstand 180℃ through modification or combination with other heat insulation materials. The material can be : For keeping cold(-200℃∼120℃) Polyurethane foam; For keeping warm (120 ℃∼300℃) Polyurethane foam+ Silica (mineral wool)
Glass fiber reinforced plastics pipe is a glass fiber with resin matrix wound layer by layer on the rotating core mold according to the process requirements, and quartz sand as its sandwich layer. Generally, glass fiber reinforced unsaturated resin, epoxy resin and phenolic resin are used according to ASTM D-3350…Resin Type III, Grade P34.
We supply and manufacture high quality pre-insulated steel pipes in accordance with EN, DIN, ASTM, GB standards for applications like Chilled Water, Condensate, Domestic Water, Heating Hot Water, Petroleum Products and Potable Water, which specified delivery conditions and final customer specifications for for industrial and commercial applications. Special sizes of steel pipes and delivery issues can be further negotiated and we provide a wide range of solutions for purchasing departments to select alternative grades without specifying product specifications.