The launching meeting of group standard preparation work was successfully held

According to the document requirements of China Building Metal Structure Association (China Construction Gold Association standard Letter [2022] No. 110), the water supply and drainage Equipment branch of China Building Metal Structure Association and Ningbo Yi Ji Valve Manufacturing Co., Ltd. are jointly responsible for the formulation of CCMSA standard "Double eccentric metal hard seal butterfly Valve for water supply and drainage" (hereinafter referred to as the standard).

In order to ensure the smooth development of the preparation of standards, and make the preparation of standards more normative, professional, industry-leading and implementation. China Building Metal Structure Association water supply and drainage Equipment Branch and Ningbo Yiji Valve Manufacturing Co., LTD., in the country to invite relevant scientific research units in the industry, production and construction enterprises and other representative units to participate in the preparation of this standard.

On July 8, the group standard preparation work launch meeting was successfully held. The launch meeting was held in a combination of online and offline, Liang Yuefeng, deputy secretary general of China Building Metal Structure Association, and Si Wujun, chairman of Ningbo Yiji Valve Manufacturing Co., LTD., delivered a speech. More than 40 people participated in the launch meeting online and offline.

01

China's urbanization rate continues to increase, urban development shows an increasing trend, and the supporting urban water supply and drainage pipe network also continues to expand, urban pipe networks are scattered, and the medium flow in the pipe network is complicated. Urban water supply network urgently needs a positive and reverse two-way sealing reliable, anti-aging, anti-erosion, anti-abrasion, corrosion resistance, long service life butterfly valve.

At present, most of the domestic rubber sealed butterfly valves are flooding the market, for example, when the rubber sealed butterfly valve is closed, the rubber sealing ring extends outward and closely with the seat through compression and expansion to achieve forced sealing; The surface tension of the rubber sealing ring is large, the relative friction between the rubber sealing ring and the valve body taper valve when the butterfly valve is opened and closed is easy to crack and damage, and the service life of the butterfly valve is short.

For the normally closed butterfly valve, the rubber sealing ring and the valve body metal taper seat for a long time, easy to appear aging bond, butterfly valve opening and closing rubber sealing ring is easy to tear phenomenon, also affect the service life of the valve. Rubber sealing ring is easy to age, easy to scratch leakage, short service life, resulting in frequent valve replacement, a large waste of social resources, frequent water outage accidents, seriously affecting the people's happiness index.

02

In order to improve the status quo, some valve companies have tried to improve, such as the development of three-eccentric butterfly valves, but there are still many drawbacks.

First, the three-eccentric butterfly valve for water supply and drainage conditions of the sealing ring is mostly multi-level sealing ring (stainless steel plate and rubber asbestos plate sandwich combination), pipeline water, rubber asbestos expansion and valve body taper valve seat seal, but when the valve is opened, the non-metallic sandwich is washed by water, water swelling rubber asbestos board (or graphite) into fragments loss, several times after opening and closing the valve, The seal will leak, and the rubber asbestos board is identified as a carcinogen, so this valve is not suitable for the urban water supply and drainage network.

Second, the sealing pair of the three-eccentric butterfly valve is a cone-to-cone rigid seal. When the butterfly valve is subjected to reverse media pressure, the butterfly plate and valve shaft will inevitably deform and displace under the action of huge media pressure, resulting in leakage of the sealing pair; When the butterfly valve is subjected to positive medium pressure, the butterfly plate and valve shaft will inevitably deform and displace under the action of huge medium pressure. The tighter the sealing ring and the seat are, the better the sealing effect is, but the valve opening and closing torque is too large, the valve opening and closing is difficult, and the valve diameter for water supply and drainage is large, and the problem is more prominent.

Third, the three-eccentric butterfly valve is a German Adams-patented structure, the design principle is that when opening and closing, the sealing ring and the valve seat are frictionless opening and closing, the sealing pair does not have self-cleaning function, and the sealing part is easy to deposit water. Impurities such as sediment, the valve is not tightly closed, affecting the sealing effect, such valves are suitable for high temperature and high pressure media, and are not suitable for water supply and drainage pipe networks.

The double eccentric metal hard seal butterfly valve for water supply and drainage effectively solves the above pain points and difficulties, and is truly a special butterfly valve designed for urban water supply and drainage.

03

Double eccentric metal hard seal butterfly valve has been widely used in the domestic major water company, there are several manufacturers in the country, water users of this product structure and design principle of higher evaluation, after many years of use of water company verification, excellent performance, good effect, the performance of the conventional rubber seal butterfly valve and three eccentric butterfly valve has been greatly improved.

According to the requirements of relevant water users and industry colleagues, draft this standard to standardize the design, manufacturing, inspection, use, etc., so that the product quality is more perfect, promote the industrial upgrading of valve products, better serve the urban water supply and drainage, and better serve the national economy and people's livelihood.

Company profile

Ningbo Yiji Valve Manufacturing Co., LTD., founded in 1958, is a national high-tech enterprise with a history of more than 60 years with large and medium-sized valve manufacturing qualifications and a national specialized special new "little giant" enterprise. It is a member of China Urban Water Supply and Drainage Association, China Electricity Council, Sinopec and CNOOC Group qualified suppliers, China General Machinery Industry Association Valve branch director unit, China Building Metal Structure Association Valve Committee vice president unit and Ningbo Quality Management Association member unit.

The factory covers an area of 33,300 square meters, with a Zhejiang Province high-tech enterprise research and development center, is also a national artisan innovation and entrepreneurship base, college students employment practice base, with domestic first-class level of finishing equipment, special equipment, physical and chemical equipment and a full range of valve testing equipment.