Adjustment and Leak Repair Tutorial for Bellows Globe Valve Before Installation
Release date:
2021-11-01
Bellows globe valves need to be adjusted before installation and use, so everyone knows how to adjust bellows globe valves! What should be paid attention to during adjustment? Open pressure regulation Before shipment, the swing pressure of the bellows globe valve needs to be adjusted to the set value required by the user.
Bellows globe valves need to be adjusted before installation and use, so everyone knows how to adjust them. Bellows globe valve ! What should be noted during adjustment?
Open pressure adjustment
Before shipping, the bellows globe valve's swing pressure needs to be adjusted to the user's required set value. If a recommended spring working pressure level is given, it usually needs to be adjusted according to the lower limit of the pressure level. Before installing the bellows globe valve onto the protective equipment or before installation, it needs to be readjusted on site to ensure Bellows globe valve that the set pressure value meets the requirements. By rotating the adjustment screw within the spring working pressure range displayed on the nameplate, the opening pressure can be adjusted by changing the spring compression. Before rotating the adjustment screw, the valve inlet pressure must be reduced to below 90% of the opening pressure, so that when rotating the adjustment screw, the valve disc can be driven to rotate, preventing damage to the sealing surface.
To ensure the accuracy of the opening pressure value, Bellows globe valve the medium conditions during adjustment should be as close as possible to actual operating conditions. The type of medium may change. Especially when the medium accumulation state differs, the opening pressure often varies. With increasing operating temperature, the opening pressure usually decreases. Therefore, when performing high-temperature adjustments at room temperature, the pressure value set at room temperature should be slightly higher than the required opening pressure. The valve's structure and material selection depend on the application and should follow the manufacturer's instructions. Traditional bellows globe valves are used for fixed additional back pressure. If the opening pressure is adjusted after inspection, the required opening pressure value should subtract the additional back pressure value.
Causes of leakage in bellows globe valves
1. Loose sealing ring connection threads, screws, and pressure rings.
2. The sealing strip is not tightened.
3. The sealing parts are connected and corroded.
4. The seal is welded to the valve body, causing surface quality degradation.
Maintenance methods for bellows globe valves
1. Remove screws and pressure rings for cleaning, replace damaged parts, polish sealing surfaces and connection platforms, then reassemble. For parts with severe corrosion damage, repairs can be made by welding, bonding, etc.
2. Leakage in the sealing rolling area requires filling with glue and then rolling to fix it.
3. If the sealing connection surface is corroded, it can be repaired by polishing, bonding, etc. If it cannot be repaired, the sealing parts need to be replaced.
Sealing rings should be repaired according to welding specifications. If curved surface parts cannot be repaired, the original curved surface treatment method needs to be removed.
The main method to determine the open or closed state of the globe valve during use is to observe the height of the valve stem exposed from the valve, thereby controlling the valve operation. There may be gaps in the connection parts between the valve and the valve, which can easily cause medium leakage and can be solved by packing seals. The valve screws of small bellows globe valves are installed inside the valve, so during use, long-term contact with the medium can easily cause corrosion by the medium.
Therefore, to prevent shortening the service life of bellows globe valves, manufacturers believe that the installation of globe valves should refer to the fluid flow, maintaining low fluid inflow in the pipeline, that is, valves with flow from bottom to top. The purpose of this installation is to reduce fluid resistance inside the valve, thereby reducing the force required to open and close the valve. In addition, after the valve is closed, it can keep the valve and the charging letter from contacting the medium, thereby reducing damage and leakage.
More information
Contact Us
Email: mj@jsmjfy.com
Address: No.288,Huanghai RD,Haian City, Jiangsu Province,China
Mobile Website