According to the structural characteristics of marine valves, marine valves can be divided into gate valve, globe valve (ball valve), check valve, safety valve, throttle valve, drain valve, etc. Marine gate valves are installed without directivity.

　　Marine gate valve has the characteristics of small fluid resistance wide range of pressure temperature, which is the most commonly used block valve to cut off connect the medium in the pipeline. Diameter shrinkage can reduce the size of parts, reduce the opening closing force, expand the application range of parts. But after the diameter shrinks, the fluid resistance loss increases.

　　Cast iron is widely used in low-pressure gate valves in China. The valve body of cast iron gate valves often suffers serious problems such as frost cracking gate falling off. The carbon steel stem of cast iron gate valves is easy to rust, the quality of packing gasket is poor,

　　1、 Serious internal external leakage

　　1. Light weight: the body is made of high-grade nodular cast iron, which is about 20% ~ 30% lighter than the traditional gate valve, easy to install maintain.

　　2. Integral coating: the ram adopts high-quality rubber for integral inner outer coating. The European first-class rubber vulcanization technology enables the vulcanized ram to ensure good geometric dimensions, the rubber nodular cast RAM are firmly connected, which is easy to fall off has good elastic memory.

　　3. Flat bottom gate seat: the traditional gate valve often uses the same flat bottom design as the water pipe machine after flushing, which is easy to cause water leakage due to the deposition of foreign objects such as stones, wood blocks, cement, iron filings other debris in the groove of the valve bottom. The elastic seat seal gate valve bottom adopts the same flat bottom design as the water pipe machine, which is easy to cause debris deposition make the fluid unobstructed.

　　4. Investment casting valve body: the valve body adopts precision casting, the geometric size makes the valve body internal without any finishing to ensure the sealing of the valve.