Valves Course Time

Marine Valves

Jan. 16, 2024

Marine valves are devices used to control the pressure, flow and flow direction of fluids in ship pipelines to meet ship environmental conditions. The valve is a control device for fluid pipelines. Its basic function is to connect or cut off the flow of pipeline media, change the circulation of the medium, change the flow direction of the medium, regulate the pressure and flow of the medium, and protect the normal operation of the pipeline equipment.

Keysmile valves’ materials include cast iron, carbon steel, alloy steel, copper alloy, aluminum alloy, titanium alloy, stainless steel, and non-metallic materials. The applicable media are mainly fresh water, sea water, air, steam, fuel, lubricating oil, etc.

Ball valves and butterfly valves, which have the advantages of light weight, small size, good sealing performance, quick and convenient opening and closing, have been gradually used on ships, and will increasingly replace globe valves and gate valves, improving the performance of ships. improve.

According to the channel direction of the stop valve, it is divided into:

1) Straight-through stop valve

2) DC stop valve: In a DC or Y-shaped stop valve, the flow channel of the valve body is in a diagonal line with the main flow channel. In this way, the degree of damage to the flow state is smaller than that of a conventional stop valve, so the pressure loss through the valve is also corresponding. It's smaller.

3) Angle stop valve: In an angle stop valve, the fluid only needs to change direction once, so that the pressure drop through this valve is smaller than that of a conventional stop valve.

4) Plunger type stop valve: This form of stop valve is a variation of the conventional stop valve. In this valve, the valve disc and valve seat are designed based on the plunger principle. The valve disc is polished so that the plunger is connected to the valve stem, and the sealing is achieved by two elastic sealing rings placed on the plunger. The two elastomeric sealing rings are separated by a collar, and the sealing ring around the plunger is pressed firmly by the load exerted on the bonnet by the bonnet nut. The elastic sealing ring is replaceable and can be made of a variety of materials. The valve is mainly used to "open" or "close", but it is equipped with a special form of plunger or special collar, which can also be used to adjust the flow.

According to the position of the thread on the stem of the stop valve, it can be divided into:

1) Threaded stem stop valve: The thread of the stop valve stem is outside the valve body. The advantage is that the valve stem is not corroded by the medium and is easy to lubricate. This structure is more commonly used.

2) Lower thread stem stop valve: The thread of the stop valve stem is in the valve body. In this structure, the valve stem thread is in direct contact with the medium, is susceptible to corrosion, and cannot be lubricated. This kind of structure is used in places with small diameter and low temperature.