I. Installation Precautions 

1. Distinguish the flow direction and do not reverse it

On the valve bodies of stop valves, check valves and throttle valves, there are flow direction arrows. They must be consistent with the direction of the medium flow. Gate valves and ball valves are generally bidirectional and usable in both directions, but those with guide holes should be noted for the correct direction. 

2. Prohibit forceful kissing and forcibly twisting the pipe

The stainless steel material is hard but brittle. If the flange is forcibly aligned, and the pipeline stress is too high, it is likely to cause the valve body to be pulled apart and the flange to deform, resulting in the failure of the seal. 

When installing, the valve should be naturally centered and the two sides of the pipes should be aligned. 

3. The gasket and the bolt must be compatible

Avoid having carbon steel gaskets and iron bolts come into direct contact with stainless steel to prevent electrochemical corrosion (rusting and sticking). 

It is recommended to use stainless steel bolts, 304/316 gaskets or polytetrafluoroethylene gaskets. 

The bolts should be tightened **in a diagonal manner and evenly**. Do not tighten them too tightly on one side. 

4. Protect the valve body during welding installation 

Welded stainless steel valve. During the welding process, ensure that the valve body is cooled down to avoid damaging the sealing components due to high temperature. 

It is strictly prohibited for welding slag to splash onto the sealing surface, the valve stem, or the packing area. 

5. The pipes must be cleaned. 

Before installation, clean the weld slag, rust and sand in the pipeline to prevent scratching the stainless steel sealing surface and causing internal leakage. 

6. Avoid prolonged direct contact with carbon steel materials

When stacking and installing on-site, do not place the stainless steel valves directly on carbon steel brackets or iron plates. It is best to use rubber sheets or wooden boards as a cushion to prevent carbonization and rusting. 

7. The stem of the valve should be protected

For the exposed parts of the valve stems of gate valves and globe valves, a small amount of lubricating grease can be applied after installation to prevent corrosion by dust and rain. 

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II. Daily Use and Maintenance Tips 

1. The switch should be in place. Do not half-open and half-close the throttling 

Gate valves and globe valves are mainly used for cutting off. If they are kept partially open for a long time, the sealing surfaces are prone to be eroded, leading to damage. 

If you need to adjust the flow rate, please use dedicated throttle valves or stop-type regulating valves. 

2. Regularly inspect the stuffing box 

When there is a slight leakage at the valve stem, you can moderately tighten the packing cover evenly. Do not tighten it all at once to avoid jamming the valve stem. 

For valves with an upper sealing structure, try to fully open them to reduce the pressure on the packing. 

3. Regularly lubricate the transmission components 

The valve stem threads, bevel gears, worm gearboxes and other moving parts should be lubricated regularly to ensure smooth operation and prevent rusting and seizing. 

4. Avoid striking the valve body

Stainless steel is relatively brittle. If it is struck forcefully with a hammer, cracks are likely to occur. For the switch, use a standard wrench or a gear wrench. 

5. Prevention of Chloride Ion Corrosion (Key Point)

304 stainless steel should not come into prolonged contact with high-concentration salt water, seawater, or chlorine-based disinfectants. 

For such conditions, 316 must be used; otherwise, the valve body will soon suffer from pitting and perforation. 

6. Be aware of thermal expansion and contraction in both low-temperature and high-temperature conditions

Avoid sudden cooling at high temperatures and sudden heating at low temperatures to prevent the valve body from cracking due to temperature difference stress. 

For outdoor and open-air valves, proper anti-freezing measures should be taken in winter to prevent the medium from expanding due to freezing and causing damage to the valve body. 

7. Valves that have not been used for a long time should be regularly operated. 

Switch it on and off at least 1-2 times per month to prevent the sealing surface from sticking together and the valve stem from rusting and getting stuck, which would make it impossible to operate next time. 

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III. Brief Summary 

- Installation: No strong pulling, no welding damage to the seal, clean the pipeline, and prevent electrochemical corrosion 

- Usage: Fully open and fully closed, without throttling, gently opened and gently closed

- Maintenance: Regular lubrication, tight packing, anti-freezing, anti-chloride ion, and regular activity