It is stipulated in the order that the valve should have an anti-static structure that can conduct electricity between the valve stem and the valve body or between the valve stem, the valve body and the ball. The anti-static circuit of the valve should have a resistance of less than 10 ohms. Take a new dry valve that has been opened and closed at least 5 times for anti-static test, and use a DC power supply not exceeding Brass Water Valve volts to measure the resistance value. Operation 4.5 Unless otherwise specified on the order, manually operated valves shall be equipped with lever-type handles.
Gear operation is recommended for valves equal to and greater than NPS6. Gear operated valves shall be equipped with a handwheel.
The length of the handle or the gear ratio of the gear mechanism shall be designed so that, according to the torque value requirements specified by the manufacturer (see Section 4.8), the input force required to operate the valve does not exceed that specified in MSS SP-91 using a position factor of 0.5 The operator loses the human capacity value.
To close the valve, tu the closing mechanism clockwise.
There should be a limit mechanism in the fully open and fully closed positions of the valve. Multi-tu handwheels should be marked with an indication of the open or closed direction.
If the valve has a rod-like handle, the handle shall be assembled parallel to the flow passage through the ball. For industrial valves, if the purchaser requires a round or oval handle, the handle shall have a permanent indication of the closed position. The design of the handle shall not allow for incorrect installation.
The opening indication of the valve should be integrated with the valve stem, which can be indicated by the mark on the stem or the shape of the stem. Handwheels, handles and other drive devices should be installed so that they can be removed and replaced without affecting the integrity of the valve stem and body seal.
When specified on the order, the valve shall be provided with a lockable (eg, padlock) locking device to enable the valve to be locked in the open and closed positions. The locking device shall be designed as a lock with a shaft diameter of 5/16 inch (8 mm) and a length of less than 4 inches <102 mm), which can be inserted through a suitable hole and locked. Even if not stated on the order, it is permissible to provide a locking device.
نویسنده : ldvalve
برچسبها : Brass Water Valve ,