What are the specific contents of the use process of fire pipe clamp interface? The following Zhongda Consulting Tendering Teacher will give you answers for your reference.
Traditional fire pipe connection methods (wire connection, welding) have gradually exposed some shortcomings in engineering applications over time. A new type of fire pipe interface - clamp type interface is used in developed cities such as Beijing, Tianjin and Shanghai. Its operation method is simple (grooving in the factory or on-site by rolling or cutting), and it is easy to disassemble and repair. Because this technology is not widely used in China, it has not been generally accepted by engineering and management personnel. The author compared the traditional fire management connection method and the clamp-type interface from the aspects of construction technology, engineering practice, installation cost, etc., and believed that the clamp-type connection is quick to install, easy to disassemble and assemble, and durable, and can reduce the overall cost in the long run. Reducing it to the lowest level is a fire pipe connection method that should be vigorously promoted and applied.
1. The evolution of fire pipe interface forms
Fire pipes with pipe diameter ≥ DN100 used to use threaded interfaces, which was very difficult to construct. This is because the pipe diameter is large and the pipe If the threads at the interface are shallow, the connection is not strong and water leakage is easy. If the threads are deep, the pipe wall at the interface threads is too thin and cannot withstand the working pressure of the system and is prone to rupture. That is to say, the old fire protection design code requires that the pipes behind the alarm valve, regardless of the size of the pipe, must be connected with threaded connections. This is defective and is the main reason why this code needs to be revised. So, what solutions have been found in subsequent engineering practices?
l. Pipes with a diameter < DN100 use threaded interfaces, and pipes with a diameter ≥ DN100 use welding or flange interfaces. , the inner wall of the pipe near the welding joint will no longer undergo anti-corrosion treatment.
2. Pipes with diameter 3. Pipes with a diameter 2. Analysis of the advantages and disadvantages of several methods l. As time goes by, the first method mentioned above exposes more and more problems, and the problems become more and more serious. serious. Because during the welding process, the high temperature destroyed the galvanized layer near the pipe interface, the iron and zinc formed a potential difference and caused electrochemical corrosion, which shortened the life of the system. The iron oxide falling off the inner wall of the pipe during the operation of the system. The pipes and nozzles are clogged, affecting the normal use of the entire system. Engineering example: In a fire on the first floor of Shenzhen Science Museum this year, after the nozzle of the automatic sprinkler system was opened by the high-temperature smoke of the fire, no water flowed out. Afterwards, the nozzle was removed and the water that flowed out Just a little bit of yellow water. After on-site investigation and discussion and analysis by experts, it was believed that the corrosion of the fire channel near the welding joints and the iron oxide falling off in the pipes blocked the pipes and nozzles, which were the main reasons for the fire-fighting failure. The fire piping system of the Science Museum was no longer functioning properly. operation, all should be replaced. The fire protection systems in buildings in many cities in China, all of which use welding, have the above problems to varying degrees. Therefore, the first method cannot be adopted, and it is also not allowed by fire protection design specifications and national standards. 2. Although the second method can ensure the quality of the project, it is expensive and requires a long construction period. It has fallen behind. Beijing, Shanghai and other places no longer do this. 3. The third method is the clamp-type interface, which should be said to be the best method at present. In the mid-1990s, some developed cities in China had more than 100 buildings, especially large and important buildings, which introduced domestic clamp-type (groove) connectors. This kind of connector has a history of production and application in foreign countries for more than 70 years, and is widely used in fire protection systems, domestic water supply systems, and air conditioning systems. Its advantages are: easy installation, short construction period, safety and reliability, a lifespan of more than 30 years beyond the pipe itself, convenient management and maintenance, and the sealing rubber ring is corrosion-resistant, aging-resistant and has shock-isolating properties. 3. The use of clamp-type connectors in some important domestic projects This kind of clamp-type connectors have been used in Beijing, Tianjin, Shanghai, Shenzhen, Nanjing, Xiamen, Chengdu and other cities have introduced and applied it, and now it is widely used in fire protection systems, domestic water supply systems, hot water systems, and air conditioning systems. Staff from our institute have conducted on-site inspections on the use of clamp-type connections in the fire protection systems of some important domestic projects, such as: Hong Kong New Airport, July 1st Return Memorial Hall, Shanghai Pudong International Airport, Jinmao Tower, Beijing Airport, Lufthansa Center, Guangzhou CITIC Plaza, International Electronics Building, IBM Shenzhen Factory in Shenzhen, Window of the World, Bao'an Stadium, Youth Palace, Happy Valley Phase II, Wenzhou Convention and Exhibition Center and other buildings all use this interface in fire protection projects. 4. Economic comparison with other fire pipe connection methods 5. Clamp connection urgently needs to be widely promoted and applied in China Over the years, some engineering personnel If you are used to welding fire protection pipes, the construction is simple and the initial cost is low. However, fire protection engineering is a century-old project, and it is impossible to sit back and relax after completing the installation at one time. The previous article has given examples of the safety hazards of fire pipe welding. We need to strengthen management from various aspects such as design, quality inspection, fire protection acceptance, etc., and resolutely put an end to the phenomenon of welding of fire protection pipelines. Compared with flange connection, the initial cost of clamp connection is 20-30% lower than flange connection, the service life is longer than flange connection, and the installation and maintenance are simple and fast, and its economic and technical advantages are It's obvious. Especially after several years of development, domestic production technology of clamp-type connectors has been greatly improved. However, due to the influence of traditional concepts over the years, or due to insufficient understanding of projects at home and abroad that have used clamp connections and achieved good results, some project managers in most areas of the country are not very accepting of this new type of connector. . As a designer, you should choose new products that are high-quality, safe, and reasonably priced so that they can be better promoted and applied. 6. Precautions when selecting clamp-type connectors l. Clamp-type connectors are made of forged steel and ductile graphite casting, and their pressure resistance is different. Reasonable selection should be made according to the actual needs of the project. 2. When inspecting clamp-type connectors, the ovality of the clamp, the fire resistance of the sealing ring and the corrosion resistance of the screws must be strictly inspected. 7. Conclusion The pipeline interface may seem like a small problem, but it is actually a key issue of the entire system. Failure to do so will affect the normal operation and use of the entire system and must be treated with caution. This issue has attracted great attention from relevant national departments. Article 8.0.3 and Article 8.0.4 of the "Design Code for Automatic Sprinkler Systems" GBJ84.85 (1999 revised version submitted for approval) emphasize: "Alarm valves should use threaded, "Flange or grooved connector (clamp) connection", "Pipelines with a diameter equal to or larger than 100MM in the system should be connected by flange or grooved connector (clamp) in sections." It is imperative to implement the above new norms. For more information about engineering/service/purchasing tender document writing and production to improve the bid winning rate, you can click on the official website customer service at the bottom for free consultation: /#/?source=bdzd