Galvanized steel pipe system, problems

Public buildings, central air-conditioning systems traditionally use galvanized steel pipe and seamless as pipelines, while the past 10 years, based on the use of a survey project, about five more projects have emerged as a serious corrosion, and Therefore, to significantly reduce the efficiency of air conditioning, heating, cooling effect greatly reduced, which led to a significant increase in operating costs. System is running 10 years later, they must all be updated pipeline (or even 3 to 5 years, was forced to reinstall all the removed), to the owners of a huge financial burden.

The ideal solution for the pipeline - in the central air-conditioning system used in aluminum plastic PP-R steady pipe

As the central air-conditioning is usually run between 7 ~ 60 ℃, the system design pressure is generally higher, we need a definite need for pipe temperature, pressure capacity. Design units, production enterprises, and construction units through continuous exploration and practice, by trying to air-conditioning piping system in the application of a new type of plastic pipe, a fundamental solution to this problem, while the economic development of Wuhan Taurus Limited for the German technology to produce non - Regulation copolymer polypropylene (PP-R) steady-state aluminum plastic composite pipe (usually referred to as PP-R steady-state aluminum plastic tube) is the preferred product to solve this problem.

Stable PP-R Aluminum plastic PP-R pipe is a pipe system, "Science update", in terms of relative galvanized steel pipe, it has the following advantages:

First, temperature, pressure performance, fully satisfy the central air-conditioning system, temperature, pressure and service life requirements; 2, non-corrosive, non-scaling, life as long as 50 years, significant savings in maintenance costs for air-conditioning systems; 3, pipe thermal conductivity coefficient (λ = 0.24W/mK), saving insulation materials in the project, project costs; 4, non-penetration of oxygen to ensure that the metal pipe in the normal operation of equipment. Pure Plastic PP-R higher than 20 ℃ under the conditions of oxygen penetration is rapidly increasing, will greatly speed up the pipeline equipment (such as pumps, valves, heat exchangers, etc.) corrosion. The aluminum plastic PP-R steady pipe in the "aluminum layer" completely blocking the infiltration of oxygen so as to prevent this from happening, to ensure the normal use of the pipeline equipment. 5, linear expansion coefficient (α = 0.03mm/mK), only plastic pipe 1 / 5, and metal pipes close to avoid deformation due to thermal expansion and contraction that occur.

As the PP-R plastic pipe both steady-state aluminum plastic pipe and metal pipe performance advantages while avoiding their shortcomings, their performance characteristics are very fit conditions of use central air-conditioning works, so the design is being more and more division, the user, and construction units accepted.

How to choose aluminum plastic PP-R steady pipe

A diameter of selection and matching. Aluminum plastic PP-R steady pipe specifications generally dn20 ~ 110mm, to meet the needs of most small and medium projects. In the large-scale air-conditioning projects, due to a larger diameter of the main risers, so should be used in large projects as the main vertical pipe seamless steel pipe. Each floor can be selected large-diameter branch pipe PP-R aluminum plastic pipe steady state.

2, pipeline specifications (pipe grade S) option. According to the characteristics of air-conditioning system operating temperature, in the PP-R aluminum plastic pipe industry standard CJ/T210-2005 steady state in Table 1, select the use of the corresponding category (in the absence of new technology based on conditions recommended by the use of this level of 4), or Table 2 according to standard in the design temperature, and the system design pressure (PD), to select the corresponding control level S. (Note: The pipe-class S is based on GB/T10798, to indicate the pipe size of the non-dimensional numerical series).

In general can be found in Table 1.

Third, the choice of insulation thickness. As the PP-R materials, the thermal conductivity of 0.24W/mK, close to the thermal insulation material. Therefore, under normal circumstances, may be appropriately thinning the thickness of insulation layer. According to the German certification relevant agencies, comparable to reduce the thickness of pipe insulation at least 1 / 3, please use the designer when the review.

4, compensation. Aluminum plastic PP-R steady pipe in vertical installation, the pipe may not take into account thermal expansion and contraction, just across the floor, take the necessary measures can be fixed. When the level of installation of more than 40 meters, they must take the necessary compensation measures. Based on the information and practice abroad conclusion that the more reasonable of the program should be: on the whole pipeline root partition with a fixed bearing reasonable use of "free-arm + part of the tube sections fixed installation" and resolve the problem, which is convenient, economic, Also safe and reliable.

Engineering Application of

Since 2001, the domestic devaluation PP-R Aluminum plastic tube, after steady state has been applied in the transformation of the old central air-conditioning, new office buildings, office buildings, residential hug central air-conditioning piping systems, residential central air-conditioning ducts and so on, through the right part of the designers, construction and technical personnel, owners, property, etc. to conduct re-survey, summed up the following points:

1, the installation of a pressure test pass rate has greatly improved significantly reduce installation schedule, installation costs, engineering, and galvanized steel pipe close to the overall result; 2, the system is running significantly reduced power consumption; 3, after more than two years on the use of pipeline inspection , did not find tube fouling phenomena; 4, the system significantly improved water quality, system operation and maintenance workload, the cost of greatly reduced; 5, pipelines and pipeline equipment, normal and stable.