3. Setting requirements of large size valves
3.1 Gear drive mechanism shall be used for operation of large size valves, and the required space position of drive mechanism shall be considered during setting.
3.2 Large size valves shall be provided with supports on one or both sides of the valve. The supports shall not be installed on the short pipes that need to be disassembled during maintenance. It shall be considered that the support of the pipe shall not be affected when the valve is disassembled. Generally, the distance between the support and the valve flange shall be more than 300mm.
3.3 The installation position of large size valves shall be provided with a site for using cranes, or consider setting up davits and lifting beams.
4. Setting requirements for valves on horizontal pipelines
4.1 Unless otherwise required by the process, in generally valve handwheel installed on the horizontal pipeline shall not face down, especially, the valve on the hazardous medium pipeline shall not have the hand wheel facing down. The position of the valve handwheel shall be determined in the following order: vertically upward; Horizontal; The vertical upward left and right tilt is 45 °; The vertical downward left and right tilt is 45 °; Do not go straight down.
4.2 For the rising stem valve installed horizontally, when the valve is opened, the valve stem shall not affect the passage, especially when the valve stem is located at the head or knee of the operator.
Unfinished (to be continued) ……
Post time: Nov-23-2022