① Water pollution caused by pipeline corrosion and scaling
② Pollution of water quality by exudates from anticorrosive lining
③ Microbial reproduction of water pollution
④ Pollution of water quality by residual chlorine disinfection by-products
⑤ External pollution caused by leakage of pipe network system
⑥ The implementation of sanitary management and supervision regulations for drinking water is not strong enough, the supervision and management mechanism is unreasonable, and poor management and other reasons cause improper sanitation management and cause water pollution.

1, the State Council issued a policy

On September 6, 2013, the State Council issued the opinions on strengthening urban infrastructure construction
◇ Premier Li Keqiang emphasized: Accelerate the transformation and construction of urban water supply facilities, actively promote the overall planning of urban and rural regional water supply, and strive to achieve the dual goals of 95% of the national urban water supply penetration rate and water quality standards by 2015.
● In 2015, the State Council officially issued the "Water Ten Articles", with special emphasis on
◇ Clarify the drinking water standard time, main rectification measures, detection methods and detection points and the main body responsible for the implementation
◇ By 2020, the quality of centralized drinking water in cities above the prefecture level will reach or be better than the three categories, and the overall proportion will be higher than 93%
◇ By 2030 or so, the proportion of centralized drinking water quality in cities above prefecture-level cities to or better than three categories is generally higher than about 95%

2, the central ministries issued policies

●In January 2007, the Ministry of Health issued a new drinking water standard GB5749-2006 the "Sanitary Standards for Drinking Water". The water quality monitoring indicators for residents' drinking water were increased from 35 to 106, and water quality monitoring sampling points were required to be extended to The end of the pipe network.
●The notice and GB50015 of the "National Civil Building Engineering Design Technical Measures" issued by the Ministry of Housing and Urban-Rural Development on January 2, 2013 The "Code for Design of Building Water Supply and Drainage" clearly emphasizes that water supply pipes should be thin-walled stainless steel pipes.
On February 17, 2015, the Ministry of housing and urban rural development, the national development and Reform Commission, the Ministry of public security and the health and Family Planning Commission jointly issued the notice on strengthening and improving the construction and management of secondary water supply facilities for urban residents to ensure water quality safety, which will improve the quality of secondary water supply to the height of the national anti-terrorism strategy, It is clear that the pipelines, pools and equipment from household water meters (including) to municipal water supply facilities are entrusted by the owners or designated by the local people are responsible for operation and maintenance, actively encourage water supply enterprises to gradually extend the management of water supply facilities to residential water meters.
●The Ministry of Housing and Urban-Rural Development issued the "CJJ/T110-2017: Technical Regulations for Direct Drinking Water Systems for Buildings and Communities" on May 15, 2017, which clearly pointed out that the direct drinking water system should use stainless steel pipes and other high-quality pipes that meet food-grade requirements.
●The Ministry of Housing and Urban-Rural Development specifically pointed out in the "GB/T50378-2019 Green Building Evaluation Standards" implemented on August 1, 2019: Indoor water supply pipelines require stainless steel pipes and fittings.
The GB50015-2019 "Building Water Supply and Drainage Design Standard" implemented on March 1, 2020 points out that indoor water supply pipes should be made of stainless steel pipes with corrosion resistance and convenient installation and connection.

3. Local government policy

●Fujian, Changsha, Shenzhen, Nantong and other places have issued relevant regulatory documents, formulated technical specifications for secondary water supply pipeline systems, and clearly stipulated that secondary water supply pipelines into households should use stainless steel pipelines.

Home decoration

Double clamping connection

When decorating the family, double-clamping thin-walled stainless steel pipes and fittings are selected to form a loop connection and series connection, so that any point of water can promote the circulation exchange of water in the whole pipeline system to form a running water pipe network.
① Stainless steel pipe health environmental protection
The thermal insulation performance of stainless steel water pipe is 24 times that of copper pipe, which reduces the heat loss and is especially suitable for hot water transportation.
③ The running water pipe network reduces the breeding of microorganisms and ensures the sanitation of drinking water without problems.
④ Stainless steel material, no corrosion and exudation, no odor or turbidity problems, will not cause secondary pollution to the water quality, keep the water quality pure and hygienic, and the hygiene is fully guaranteed.
⑤ Beautiful appearance, clean and fashionable will help to improve the grade of urban buildings, which can be installed in the open or in the dark.

GB/T29038-2012-Walled Stainless Steel Piping-Technical Specification
22S407-2 "thin wall stainless steel water supply pipe installation"
CECS153-2003 "Technical specification for building water supply thin-walled stainless steel pipe engineering"