Day: 30 April 2021

Valve is used to control the flow of the liquid and gases in pipe line. On board ship there are so many pipe lines so valve is most useful device to control the flow of the liquid. there are so many types of valve are used on board the ship.Some valves are listed below 1. Gate valve2. Globe valve3. Butter fly valve4. Safety valve5. Pressure relief valve6. Check valve7. Diaphragm Valve8. Solenoid valve9. Pilot valve 1.GATE VALVEGate valve is used to allow and stop the full flow of the liquid. This valve is mostly used in ballast system line and cargo discharge line where we required full flow of the liquid.The gate valve is also known as the sluice vale which is very common name used on board ship.The gate valve consist a disc which lower or rise by rotating the valve stem which allow open or close the valve.Gate valve can not use for vary the flow of the liquid because it can cause damage the valve disc. 2. GLOBE VALVEGlobe valve is normally known as none return valve. There are different types of globe valve used onboard ship.1. Screw down non return valve [ SDNR]2. Screw down stop valve3. Globe type check valveScrew down non return valve is used in blige system pipe line and also used in steam system. This valve gives one way flow that means its non return valve. This valve is suitable for varying the flow of the liquid. If we will talk about the construction of the globe valve (SDNR) the valve disc is not attached with the spindle and the construction of the valve spindle is sctew type so when we rotate the hand wheel (actuator) screw will move up and down but disc will be placed on the valve seat. Valve disc will lift with the help of liquid pressure. Components of Globe valve1. Hand wheel nut2. Hand wheel3. Valve spindle or valve stem4. Gland flange5. Gland flange nut6. Yoke and Yoke bush7. Bonnet or cover8. Body and flanges 9. Valve disc and seat