General Instructions for Soft-Seated Ball Valves

I. Main Applications and Scope of Use
1. Application
Soft-seated ball valves are designed for on/off applications and are not suitable for regulating purposes (partially open or closed positions can cause the seat seal to bounce and deform, resulting in the valve failing to close properly).

2. Scope of Application
Temperature (°C)
Operating Pressure:
Service Medium:
Notes: Prolonged operation at the upper limits of the valve’s operating range (temperature and pressure) may affect the valve’s service life; it is recommended to use higher-grade products.

3. Performance Specifications

II. Main Structural Features:
The ball rotates 90° perpendicular to the axis to open and close the valve; the design is compact and operation is rapid. In particular, large-bore ball valves feature a floating ball, resulting in low torque and easy operation. The ball and the annular seat achieve a seal under the combined action of preload and the force of the medium, ensuring a reliable seal.

III. Main Components and Materials:

IV. Installation
1. The ball valve must be installed in a position that facilitates operation and maintenance.
2. Prior to installation, verify that the valve’s specifications, performance standards and technical requirements are compatible with the operating conditions.
3. Before installation, remove all debris and rust from the valve interior to ensure the sealing surfaces are clean.
4. Inspect for any transport damage; installation may proceed only after a satisfactory inspection.
5 It is recommended that the ball valve be installed in the closed position.

V. Operation

1 Soft-seated ball valves are intended solely for on/off applications; in particular, they must not be used under conditions exceeding temperature or pressure limits, or in environments subject to frequent pressure fluctuations. At high temperatures, bolts may be periodically tightened to prevent leakage and to minimise thermal gradients. At low temperatures, impact loads and high stress concentrations must be avoided.
2 The ball valve must be kept in either the open or closed position and should not be used for regulation. When operated by non-manual means, the valve’s open/closed position must correspond to the switch position and indicator on the control panel to prevent incorrect operation.

VI. Maintenance and Storage
1 Valves in operation must be inspected and maintained regularly to prevent rust and jamming, ensuring the equipment remains in good working order at all times.
2 Installed valves must be kept clean, and the stem must be well lubricated.
3. In the event of external leakage at the packing gland, check whether the packing is sufficiently tightened (excessive force should be avoided).
4. In the event of external leakage at the flange, retighten the bolts evenly until the leak is eliminated.
5. In the event of internal leakage at the sealing face, check whether the valve is fully closed and whether there are any foreign objects on the sealing face. Where permissible, open the valve and then close it again to check for leakage.
6. If leakage persists after maintenance, the valve requires repair.
7 During valve maintenance, parts must be thoroughly cleaned to remove foreign objects, dirt and rust. Replace damaged packing and gaskets, and rectify the sealing surfaces. The valve may only be returned to service after successful maintenance and pressure testing.
8 Valves must be stored in a dry warehouse; stacking and outdoor storage are strictly prohibited.