1. When polyurethane is poured, the construction environment temperature should be 10-40 C and the relative humidity should be less than 80%.
2. The rigid foam polyurethane insulation layer after filling should be fully ripened before stopping the construction of the next process.
3. The surface of rigid foam polyurethane insulation layer after filling should be lubricated without obvious depression and prominence.
According to the different sliding modes, the thermal insulation structure of steel-jacketed composite thermal insulation steel pipe can be divided into two categories:
Inside sliding type: thermal insulation structure consists of working steel pipe, aluminium silicate, drag reduction layer, micro-porous calcium silicate, thermal insulation layer, stainless steel fastening strip, aluminium foil reflective layer, polyurethane thermal insulation layer, coated steel pipe and external anti-corrosion layer. Inside sliding insulating steel pipe is anti-corrosion maintenance of steel pipe with delivery medium + composite silicate or micro-porous calcium silicate + rigid polyurethane foam plastic + outer sleeve steel pipe + FRP shell.
External sliding type: thermal insulation structure consists of working steel pipe, glass wool thermal insulation layer, aluminum foil reflective layer, stainless steel fastening belt, sliding guide bracket, air thermal insulation layer, external steel pipe and external anti-corrosion layer. Layer structure. All kinds of tubular joint heat preservation treatment technology is mature and the quality is reliable.
Steel-jacketed steel composite insulation pipe is one of the open direct buried pipelines. It can stop the open direct burial without concrete structure, that is, the thermal shrinkage of the working steel pipe stops in the outer pipe, which reduces the cost of data, shortens the construction date, and ensures the safety of the heating pipeline. It can be used safely in different temperature environments, especially suitable. Used in high temperature steam pipeline project. The application temperature can reach to - 450 C. Pipeline ports are usually sealed with polyethylene film or three layers of PE cold wrapping tape to avoid entering moisture or water before installation or during construction. The multi-layer staggered seam binding of thermal insulation data effectively reduces the heat loss, and takes control measures on the outer surface of the coat to avoid the cold bridge, thus ensuring the temperature control of the coat anticorrosive layer. The multi-layer aluminum foil reflector coated with thermal insulation material can effectively reduce the heat loss and make the steam pipeline more economical and reasonable.
The drainage system is completely blocked, with sensitive layout, reasonable structure and safe and reliable operation. The tidal tube on the steel sleeve can not only discharge wet gas in time, but also serve as an alarm signal tube for daily operation. High quality bellows compensator is used for heat compensation of pipeline, and it is installed in casing to make it buried directly. There is no need to install inspection wells, so the construction operation is convenient and the construction period is short. It is suitable for escorting steam or other media below 2.5 MPa and 350 degrees Celsius. The product uses steel pipe as outer protective layer. It has the advantages of high strength, not easy to damage, cumbersome construction and maintenance, and long service life.
