In the industrial field, sealing technology is one of the key links to ensure the safe and efficient operation of equipment. As a sealing element with excellent performance, metal spiral wound gaskets are widely used in flange connections of various pipes, valves, pressure vessels and other equipment. This article will comprehensively introduce the relevant knowledge of metal spiral wound gaskets, including its definition, classification, application scenarios, market demand and trend analysis, materials and new technologies, as well as installation, use, maintenance and other aspects, to provide you with a guide to deeply understand metal spiral wound gaskets.
1. Definition and structure of metal spiral wound gasket
Metal spiral wound gasket is a semi-metallic sealing gasket, which is made of V-shaped or W-shaped thin steel strips and various fillers alternately wound. This unique structure gives the metal spiral wound gasket good compression and resilience, enabling it to maintain excellent sealing performance under various harsh conditions such as high temperature, high pressure, high vacuum, impact vibration, etc. In order to strengthen the main body and accurately position, the spiral wound gasket is usually equipped with a metal inner reinforcement ring and an outer positioning ring, and the inner and outer steel rings are used to control its maximum compression. At the same time, the surface accuracy of the flange sealing surface contacted by the gasket is not high.
2. Classification of metal wound gaskets
(I) Classification by structural form
Basic wound gasket: made of metal and non-metallic belts directly spirally wound, without inner and outer rings, suitable for occasions with relatively low sealing requirements such as tongue and groove flanges.
Wound gasket with inner ring: based on the basic type, a metal inner ring is added to improve the gasket's pressure resistance and sealing performance, suitable for concave and convex flanges.
Wound gasket with outer ring: with a metal outer ring, it can better protect the gasket and prevent it from being damaged during installation and use. It is suitable for flat and raised flanges.
Wound gasket with inner and outer rings: with both metal inner and outer rings, it has the best comprehensive performance and is widely used in various types of flange connections.
(II) Classification by filling material
Graphite wound gasket: The filling material is graphite, which has good high temperature resistance and chemical corrosion resistance. The operating temperature can reach -200~550, and the maximum operating pressure can reach 250kg/cm². It is suitable for a variety of media, such as steam, oil, oil gas, solvents, etc.
Asbestos wound gasket: filled with asbestos, the temperature range is -150~450, and the maximum operating pressure is 100kg/cm². However, as asbestos is harmful to human health, its use is gradually restricted.
PTFE wound gasket: With PTFE as the filling material, it has excellent chemical stability and corrosion resistance. The operating temperature is -240~260, and the maximum operating pressure is 100kg/cm². It is often used in occasions with extremely high requirements for corrosion resistance.
3. Application scenarios of metal wound gaskets
Due to their excellent performance, metal wound gaskets are widely used in the static sealing of flange connections such as pipelines, valves, pressure vessels, condensers, heat exchangers, towers, manholes, hand holes, etc. in many industries. The specific application scenarios are as follows:
Petrochemical industry: In the process of oil refining and chemical production, it involves the transportation and reaction of various high-temperature, high-pressure, and highly corrosive media. Metal wound gaskets can ensure the sealing reliability of the equipment, prevent medium leakage, and ensure production safety.
Power industry: Whether it is thermal power generation, hydropower generation or nuclear power, metal wound gaskets play an important sealing role in pipeline systems, steam turbines, condensers and other equipment to ensure the stable operation of power production.
Metallurgical industry: High-temperature furnaces, pipeline transportation and other links in the metallurgical process need to withstand high temperature, high pressure and harsh working environment. The excellent performance of metal wound gaskets makes it an ideal sealing choice.
Ship industry: The power system and pipeline system of ships have strict requirements on sealing. Metal wound gaskets can adapt to the vibration and pressure changes of ships under different working conditions to ensure the safe navigation of ships.
Pharmaceutical industry: Pharmaceutical production has extremely high requirements for environmental cleanliness and safety. The sealing performance of metal spiral wound gaskets can effectively prevent drug contamination and meet the strict standards of the pharmaceutical industry.
High-tech fields such as atomic energy and aerospace: These fields have almost stringent requirements for equipment reliability and safety. The excellent sealing performance of metal spiral wound gaskets under extreme conditions such as high temperature, high pressure, and high vacuum makes them an indispensable sealing component.
4. Market demand and trend analysis
With the acceleration of global industrialization, the demand for metal wound gaskets in various industries continues to grow. In particular, the rapid development of emerging economies, such as China and India, has led to the prosperity of the metal wound gasket market. At the same time, increasingly stringent environmental protection requirements have prompted companies to pay more attention to the sealing performance of equipment to reduce the impact of leakage on the environment, which has further promoted the demand for the metal wound gasket market.
In the future, the metal wound gasket market will show the following trends:
Growing demand for high-performance products: With the continuous advancement of industrial technology, the requirements for high temperature resistance, high pressure resistance, corrosion resistance, wear resistance and other performance of metal wound gaskets will become higher and higher. The research and development and production of high-performance and multifunctional metal wound gaskets will become the key to market competition.
Environmentally friendly products are favored: Due to the potential harm of asbestos wound gaskets to the environment and human health, their use will gradually be eliminated. Environmentally friendly graphite wound gaskets, polytetrafluoroethylene wound gaskets and new asbestos-free wound gaskets will become the mainstream of the market.
Increasing demand for customized services: Different industries and different equipment have different specifications and performance requirements for metal spiral wound gaskets. Customized products and services will better meet customers' personalized needs and improve customer satisfaction.
Intelligent manufacturing promotes industrial upgrading: The application of intelligent manufacturing technology in the production of metal spiral wound gaskets will continue to deepen, improve production efficiency, product quality and consistency, reduce production costs, and promote the upgrading and development of the entire industry.
5. Materials and New Technologies
(I) Material Innovation
New Metal Strip Materials: In addition to traditional stainless steel strips (such as 304, 316, 316L, etc.), some new alloy materials, such as nickel-based alloys and titanium alloys, are gradually used in the production of metal spiral wound gaskets because of their higher strength, corrosion resistance and high temperature resistance, to meet the sealing requirements under special working conditions.
High-performance filling materials: Research and develop filling materials with higher performance, such as new graphite materials, high-performance ceramic fibers, nanocomposites, etc. These materials can not only improve the sealing performance of the gasket, but also enhance its stability and durability under extreme conditions.
(II) Application of New Technologies
Digital Design and Manufacturing Technology: Using computer-aided design (CAD), computer-aided manufacturing (CAM) and simulation analysis software, the structure and performance of metal spiral wound gaskets are optimized, the production process is automated and precisely manufactured, and product quality and production efficiency are improved.
Surface treatment technology: By performing special treatment on the surface of the metal strip, such as coating and plating, the corrosion resistance and wear resistance of the metal spiral wound gasket can be further improved, and its service life can be extended.
Intelligent sealing technology: Integrate sensors, intelligent control and other technologies into metal spiral wound gaskets to achieve real-time monitoring and intelligent adjustment of the sealing status, timely detect and solve sealing problems, and improve the reliability and safety of equipment operation.
6. Installation and Use
(I) Preparation before installation
Check whether the specifications, models and materials of the gaskets are consistent with the requirements of the equipment. The surface of the gaskets should be free of defects such as cracks, scratches and rust.
Clean the flange sealing surface, remove oil, impurities, rust, etc., and ensure that the sealing surface is flat and smooth.
Prepare installation tools such as wrenches, screwdrivers, gasket installers, etc.
(II) Installation process
Place the gasket correctly on the flange sealing surface. For gaskets with inner or outer rings, ensure that the inner or outer rings match the corresponding grooves or bosses of the flange well.
Use the symmetrical tightening method to gradually tighten the flange bolts so that the gasket is evenly compressed. During the tightening process, pay attention to moderate force to avoid over-tightening that may cause gasket damage or seal failure.
After installation, check again whether the gasket is installed in the correct position and whether the bolts are tightened in place.
(III) Precautions for use
Operate strictly in accordance with the operating temperature and pressure range of the gasket to avoid over-temperature and over-pressure operation.
When pressure and temperature fluctuations occur during the operation of the equipment, pay close attention to the sealing performance of the gasket. If leakage is found, take timely measures to deal with it.
Avoid frequent start and stop of equipment, because frequent temperature and pressure changes will have an adverse effect on the sealing performance of the gasket.
7. Maintenance and care
Regular inspection: Regularly check the metal wound gaskets on the equipment to see if the gaskets are damaged, deformed, leaking, etc. If any problems are found, the gaskets should be replaced in time.
Cleaning and maintenance: Keep the gaskets and flange sealing surfaces clean, and regularly clean the dirt and impurities on the sealing surfaces to prevent them from causing wear or corrosion to the gaskets.
Prevent corrosion: For metal wound gaskets used in corrosive media environments, corresponding anti-corrosion measures should be taken, such as selecting corrosion-resistant gasket materials and anti-corrosion treatment of the sealing surfaces.
Proper storage: If the gasket needs to be stored for a long time, it should be placed in a dry, ventilated, and light-proof environment to avoid moisture, oxidation, and deformation.
As an important sealing element in the industrial field, metal wound gaskets play a vital role in the operation of equipment in various industries. By understanding its definition, classification, application scenarios, market demand and trends, materials and new technologies, as well as correct installation, use, and maintenance methods, the performance advantages of metal wound gaskets can be better utilized to ensure the safe and efficient operation of equipment. With the continuous advancement of technology and changes in market demand, metal spiral wound gaskets will continue to innovate and develop, providing more reliable sealing solutions for industrial production.
