Valve sealing surface leakage treatment method Is the valve need to install bypass valve principles and Settings?

Valve sealing surface leakage treatment method Is the valve need to install bypass valve principles and Settings?

Screw the bolts evenly and symmetrically. If necessary, use a torque wrench. The preload should meet the requirements and not be too large or small. There should be a certain preload clearance at the joint of flange and thread. The gasket assembly should be aligned with the center and the force should be uniform. The gasket lap and double gasket are not allowed.
Cause:
1, sealing surface grinding uneven, can not form a close line.
2. The connection between the stem and the closing part is suspended, not straight or worn.
3, the valve stem bending or assembly is not correct, so that the closing part is skewed or not in the middle.
4. Improper selection of sealing surface material quality or not selection of valve according to working conditions.
Prevention and elimination methods:
1. Correctly select the material and type of bouncing gasket according to the working conditions.
2, careful adjustment, smooth operation.
3, should be evenly and symmetrically screw the bolt, if necessary, should use torque wrench, preload should meet the requirements, not too large or small. There should be a certain preload clearance at the joint of flange and thread.
4, the gasket assembly should be aligned, the force is uniform, gasket lap and use of double gasket is not allowed.
5, static sealing surface corrosion, damage processing, processing quality is not high, should be repaired, grinding, coloring inspection, make the static sealing surface meet the relevant requirements.
6. When installing the gasket, attention should be paid to cleaning, sealing surface should be kerosene clear, and the gasket should not fall to the ground.
Does the valve need to install bypass valve principles and Settings? We occasionally see some relatively large valves in some pipes, and there are always bypass valves installed. Why is this? What is its main function? Under what circumstances does it need to be installed? What is the diameter of the bypass valve of the corresponding equipment? In fact, the bypass valve is set in the pipeline, and its role can be divided into two points in general: one is to play a protective role (balance pressure at both ends), the other is emergency standby!
We occasionally see some relatively large valves in some pipes, and there are always bypass valves installed. Why is this? What is its main function? Under what circumstances does it need to be installed? What is the diameter of the bypass valve of the corresponding equipment?
In fact, the bypass valve is set in the pipeline, and its role can be divided into two points in general: one is to play a protective role (balance pressure at both ends), the other is emergency standby!
First, the protective effect, can also be said to be a protective measure of the main valve, to prevent the valve before and after the pressure difference is too large, and cause open resistance, the valve is not good to open, especially in some large caliber or high pressure pipeline. Before opening the high pressure pipeline through the bypass valve pressure relief, in order to avoid high pressure suddenly inrush, the formation of impact on the pipeline below the valve. Or the pressure difference between the two ends of the valve is too large, the opening torque is too large, in order to avoid torque damage to the valve, bypass pressure relief before opening the valve.
Two, the emergency role, as a standby pipeline to use, the biggest advantage is that when the main valve failure, or the need for maintenance and overhaul, you can open the bypass valve circulation, and does not affect the normal production.
Whether the valve needs to be installed by bypass valve specific requirements and Settings * for reference)
2.5mpa grade, DN400 or above; 4.0mpa grade, DN250 or above; 6.4mpa grade, DN200 or above; 10MPa grade, DN150 or above;
DN100~DN200 valve, the bypass pipe and bypass valve for DN20; DN250~DN600 valve, the bypass pipe and bypass valve for DN25; For valves above DN600, the bypass pipe and bypass valve are DN40.