According to the structural characteristics of marine valves, marine valves can be classified into gate valves, globe valves (ball valves), check valves, safety valves, throttle valves, and steam traps, etc. Marine gate valves do not have directionality during installation. 

Marine gate valves have the characteristics of low fluid resistance and a wide range of applicable pressure and temperature. They are the most commonly used shut-off valves and are used to cut off or connect the medium in the pipeline. The reduction of the pipe diameter can make the component sizes smaller, and the force required for opening and closing is accordingly reduced. At the same time, it can expand the application range of the components. However, after the pipe diameter is reduced, the fluid resistance loss increases. 

In China, the most commonly used material for low-pressure gate valves is cast iron. Cast iron gate valves often suffer from serious problems such as valve body cracking due to freezing and the detachment of the gate plate. The carbon steel valve stems of cast iron gate valves are prone to rust, and the quality of the packing gaskets is poor. 

1. Severe leakage both inside and outside occurred. 

1. Lightweight: The body is made of high-grade ball black cast iron, which reduces the weight by approximately 20% to 30% compared to traditional gate valves, making installation and maintenance more convenient. 

2. Overall rubber coating: The gate plate is coated with high-quality rubber for both the inner and outer surfaces. The world-class rubber vulcanization technology in Europe ensures that the vulcanized gate plate maintains good geometric dimensions, and the rubber firmly adheres to the ductile cast gate plate, being less likely to fall off and having excellent elastic memory. 

3. Flat-bottomed valve seat: Traditional gate valves often have problems after water flushing, as foreign objects such as stones, wood blocks, cement, iron filings, and debris accumulate in the bottom groove of the valve, making it difficult to close tightly and causing water leakage. The bottom of the elastic seat-sealing gate valve adopts the same flat-bottom design as the water pipe machine, which is less likely to cause debris accumulation, ensuring smooth flow of the fluid. 

4. Precision Cast Valve Body: The valve body is made through precision casting. The geometric dimensions ensure that the valve body does not require any further machining to maintain its sealing performance.