Guide to Installing Marine Valves

Marine valves, as crucial components in controlling the flow and direction of media within ship piping systems, are vital to ensuring the safety and reliability of ship operations. The following is a comprehensive guide to installing various types of marine valves, aimed at assisting technicians in performing correct installations.

I. Preparation Before Installation

1. Inspection of Valves and Piping

• Ensure that the valve model and specifications meet design requirements, and inspect the valve exterior for damage.

• Clean and inspect the piping, ensuring it is coaxial, clean, and free of impurities. The piping should be able to bear the weight of the valve, and supports should be provided if necessary.

• Remove any defects that may have occurred during valve transportation, such as impurities within the valve or bent valve stems.

2. Preparation of Tools and Materials

• Prepare the necessary tools for installation, such as wrenches, torque wrenches, and sealing gaskets.

• Ensure that sealing gaskets, packing materials, etc., meet the sealing requirements and physical properties of the medium being used, and comply with environmental protection standards.

II. Installation Steps

1. Installation of Stop Valves

• Stop valves should be installed vertically with the valve stem facing upwards and the medium flowing from beneath the valve disc to above it.

• Install according to the medium flow arrow marked on the valve body.

2. Installation of Gate Valves

• Gate valve stems should be installed as vertically as possible, although it is acceptable for the handwheel to be installed vertically downwards in spaces with limited room.

• There are no specific requirements for the flow direction, but the installation should allow for easy observation of the open/close indicator.

3. Installation of Check Valves

• Lift check valves should be installed with the valve disc vertical.

• Swing check valves should be installed with the valve disc rotating upwards when opened in horizontal pipes, and with the valve disc located above the valve seat in vertical pipes.

• Install according to the medium flow arrow marked on the valve body.

4. Installation of Butterfly Valves

• Butterfly valves should be installed according to their position, with the horizontal position being optimal.

• The medium flow direction is not specified for concentric butterfly valves, but eccentric butterfly valves should be installed according to the medium flow arrow marked on the valve body.

5. Installation of Pressure Reducing Valves

• Pressure reducing valves should be installed vertically, with a filter installed at the inlet to prevent debris blockage.

• A stop valve should be installed in parallel with the pressure reducing valve to allow the system to continue operating during maintenance.

• Pressure gauges should be installed before and after the pressure reducing valve to observe pressure reduction, and a safety valve should be installed downstream to ensure pipeline safety in case of pressure reducing valve failure.

6. Installation of Ball Valves

• Before installing the ball valve, ensure it is fully open and clear any impurities from the pipeline.

• When connecting with flanges, tighten the nuts crosswise according to the specified torque.

• Cast steel flanged ball valves should be installed in horizontal or vertical positions, ensuring the pipeline is stable and without deviation.

III. Installation Precautions

1. Ease of Operation

• Valves should be installed in positions that are easy to operate, with the handwheel at chest level (typically 1.2 meters above the operating floor).

• For floor-mounted valves, the handwheel should face upwards to avoid awkward operation.

2. Seal Inspection

• After installation, conduct an air tightness test to ensure the valve is leak-free.

3. Lubrication and Commissioning

• All lubricated parts of the valve transmission should be adequately greased.

• The transmission should be tested before use to ensure all functions are intact.

4. Safety Regulations

• It is strictly prohibited to strike valves made of fragile materials.

• When lifting valves, do not tie ropes around the handwheel or valve stem to prevent damage.

• During installation, pay attention to personal protection to avoid injury from acids, alkalis, or toxic media.

IV. Subsequent Maintenance

• Regularly inspect the sealing performance of the valve and replace damaged sealing gaskets and packing materials in a timely manner.

• Regularly lubricate and maintain the transmission to ensure flexible valve operation.

• For valves that are not used for a long time, take measures to prevent rust and corrosion.

By following this installation guide, the correct installation and reliable operation of marine valves can be ensured, providing a strong guarantee for the safe operation of ships.