Sea water valve

The pressure of the marine seawater working condition valve (below 2.1Mpa) is not high, and the temperature is not high. The valve type can be selected as a midline butterfly valve.
The valve body can be selected from ductile iron or 316L/aluminum bronze: when choosing a valve body, it should be divided into submerged and non submerged types.
Non submerged valves, using ductile iron or WCB valve bodies, with anti seawater corrosion coating on the surface: the outer surface of the valve body does not come into contact with the medium, and the medium only flows inside the valve. The valve seat of the midline butterfly valve completely wraps around the internal flow channel of the valve, isolating the medium from the medium in the valve body. Therefore, if it is a non submerged valve, the valve body does not come into contact with the medium at all. The only protection needed for the valve body is the trace salt in the seawater environment and air. This can be completely protected by surface anti-corrosion coating. The valve body material can be made of basic ductile iron material.
Immersion type valve, or using aluminum bronze/stainless steel material: Immersion type valves, because the valve body is always in contact with the medium, will cause corrosion to the valve body. Based on our years of application experience in the seawater field, aluminum bronze and stainless steel materials can serve as excellent application materials in seawater, effectively preventing seawater corrosion. Therefore, aluminum bronze or stainless steel can be used as valve body materials.
The valve stem is made of 316L material
If a dry shaft design is used, the valve stem will not come into contact with the medium. Normal use of conventional martensitic stainless steel is sufficient, but considering the possibility of long-term use and lack of timely maintenance of the valve, it is recommended to use MONEL or duplex stainless steel to prevent seawater from penetrating the valve stem and causing corrosion due to wear and tear after long-term use.
The valve plate is made of aluminum bronze or double-sided stainless steel
The valve plate is completely in contact with the medium and is still in frequent operation. It is recommended to use aluminum bronze or 316L stainless steel as the valve plate material to prevent seawater corrosion. (Nylon coating on the surface of ductile iron can also be used, but this method still has the same disadvantage that nylon may be damaged or destroyed.)
The valve seat is made of EPDM rubber
EPDM rubber is suitable for seawater media, resistant to seawater corrosion, has good elasticity, strong sealing ability, and is economical. PTFE material has better corrosion resistance, but it is not necessary in seawater as seawater has not yet reached the corrosion strength of hydrochloric acid and other substances.