No matter what piping method is used for pipes arranged in the cushion under the ground, the pipes are required to have a longer service life, a smaller cushion thickness and a simpler installation method, and avoid connecting pipe fittings in the cushion. Therefore, steel pipes should not be used, only plastic pipes should be used. PE pipe - a new choice of buried heating pipes.
Floor radiant heating is used to lay pipes in the ground cushion. The low-temperature hot water floor radiant heating mode has better comfort than the traditional radiator convection heating mode, and can also save about 10% of heat energy. Compared with old heating facilities, radiant floor heating can better meet the requirements of residents for architectural decoration. In addition, Ultra wear-resistant composite pipe As the insulation layer needs to be laid on the floor base, it can partially reduce the heat transfer between households during household heat metering, improve the sound insulation of the floor and reduce the impact sound. The heating pipes for low-temperature hot water floor radiant heating should also be plastic pipes.
Here we compare various plastic pipes.
(1) The key is the effective quality control of various pipes., The quality of polybutylene pipe and random copolymer polypropylene pipe is mainly controlled by the composition and quality of raw materials. In addition to the composition and quality of raw materials, the cross-linking process of ultra wear-resistant composite pipes, cross-linked polyethylene pipes and cross-linked aluminum plastic composite pipes is crucial to quality control, which makes the quality of many such pipes out of control.
(2) Polybutylene pipe and random copolymer polypropylene pipe are renewable raw materials, which are more beneficial to environmental protection. The two kinds of pipes can also be connected by hot fusion, saving expensive connection accessories.
(3) The problem of oxygen permeation of pipes should also be considered. When sharing the same centralized heat source water system with other heating systems, super wear-resistant composite pipes and other heating systems use steel radiators and other corrosion prone components, polybutylene pipes, cross-linked polyethylene pipes and random copolymerized polypropylene pipes should have an oxygen barrier layer to effectively prevent oxygen infiltration and accelerate the oxidation and corrosion of the system. The middle layer of cross-linked aluminum plastic composite pipe is reinforced aluminum pipe, which can effectively block the penetration of oxygen.
(4) For the longitudinal linear expansion of pipes, attention should be paid to the hot pipes. The approximate values of linear expansion coefficient of plastic pipes are arranged from small to large as follows: cross-linked aluminum plastic composite pipe 0.025, polybutylene pipe 0.130, random copolymer polypropylene pipe 0.180, cross-linked polyethylene pipe 0.200. Due to the large longitudinal expansion, the pipeline is severely deformed after being heated, so it is not suitable for open installation.
(5) Low temperature resistance. The random copolymer polypropylene pipe will be brittle at low temperature under - 10 ℃, which is easy to be damaged during transportation. The brittle temperature of other pipes can be as low as - 70 ℃.
From the above comparison, we can see that none of the pipes is perfect. Therefore, pipes shall be reasonably selected according to the durability requirements of the project, service condition grade, heat medium temperature and working pressure, system water quality requirements, material supply conditions, construction technical conditions, investment costs and other factors through comprehensive comparison.
