On-site joint coating installation method used for polyurethane spraying outer protective pipe spraying integrally-formed heat preservation pipe

Abstract

The invention discloses an on-site joint coating installation method used for a polyurethane spraying outer protective pipe spraying integrally-formed heat preservation pipe. Hot-melt welding of a traditional joint coating plate and hot-melt welding of an outer protective pipe of an elastic sealing contraction band cannot improve the connecting quality, consequently, problems that foaming at a pipeline joint is uneven, and the heat preservation effect is low are causes, welding of the outer protective pipe is not firm, water seepage occurs, and pipeline heat energy loss and medium temperaturedrop are caused. The method comprises the following composition of a steel pipe A (4), the joint coating end faces of the steel pipe A (4) and a steel pipe B (2) are fixed through welding, a polyurethane foaming agent is uniformly sprayed on the exposed steel pipe A and the exposed steel pipe B at 360 degrees, after polyurethane is cured for 10 minutes-30 minutes, a polyurethane heat preservationlayer is formed, a polymer liquid elastic material is uniformly sprayed on the 360-degree surface of the polyurethane heat preservation layer by adopting a high-pressure liquid spray gun, the sprayingthickness is 1mm-20mm, the surface forming time after spraying is shorter than 60 seconds, the curing forming time is within 1 hours-24 hours, and the outer protective pipe is made of the polymer liquid elastic material. The invention relates to the on-site joint coating installation method used for the polyurethane spraying outer protective pipe spraying integrally-formed heat preservation pipe.

Description

Technical field: [0001] The invention relates to the technical field of on-site installation of prefabricated heat-insulating pipelines, in particular to a method for on-site patching and installation of polyurethane spray-coated outer protection pipes and spray-coated integrally formed thermal insulation pipes. Background technique: [0002] It has been 40 years since prefabricated direct-buried thermal insulation pipes were introduced into China in the 1980s. It has improved the thermal efficiency of China's central heating and saved a lot of energy. However, with a large number of applications, the connection at the pipe interface needs to be constructed on site. Due to the construction time Due to reasons such as urgency and natural temperature drop, after the pipe is welded to the steel pipe, the traditional hot-melt welding of the insulation pipe joint and the hot-melt welding of the outer protective pipe of the elastic sealing shrinkage belt cannot improve the quality ...

AI Technical Summary

Problems solved by technology

[0002] It has been 40 years since prefabricated direct-buried thermal insulation pipes were introduced into China in the 1980s. It has improved the thermal efficiency of China's central heating and saved a lot of energy. However, with a large number of applications, the connection at the pipe interface needs to be constructed on site. Due to the construction time Due to reasons such as urgency and natural temperature drop, after the pipe is welded to the steel pipe, the traditional hot-melt welding of the insulation pipe joint and the hot-melt welding of the outer protective pipe of the elastic sealing shrinkage belt cannot improve the quality of the connection, resulting in the failure of the pipe joint. Inhomogeneous bubbles, low heat preservation effect, poor welding of the outer protective pipe, and water seepage from welding are the main reasons for poor heating quality such as heat energy loss in the pipeline and drop in medium temperature

[0003] The welding of the original jointing plate is to add electric heating to both ends of the jointing plate after it is wrapped. On the surface, the binding is firm, and the hot-melt welding is integrated. However, due to the low temperature of the outer protective tube of the pipeline, or the binding is not tight, the outer protective tube is damaged. The thermal fuse cannot be touched and cannot be melted, but the jointing plate is melted and pasted on the surface of the outer protective tube, so that the outer protective tube and the jointing plate will never be integrated. With the change of temperature and the extrusion of the soil, the sticking is not firm There will be gaps and cracks in the position, and the moisture in the soil will immediately enter the insulation layer, resulting in a significant decline in the insulation effect and affecting the service life of the pipe network.

Images