When selecting a driving device for a valve, the following precautions should be taken:
1. Determine the driving mode according to the application and purpose of the valve:
manual, electric, pneumatic, hydraulic.
2. Manual mode selection:
The specifications for ball valves and butterfly valves are DN150 and can be driven by a handle; When the specification is DN200, a worm gear drive should be selected.
The specification of the gate valve for DN400 can be driven by a handwheel; When the specification is DN450, a gearbox drive should be selected.
The specification of the C gate is 600X600, and a handwheel hoist can be selected; Specification: A gearbox hoist should be selected for 700X700.
The specification of the D shut-off valve is DN150, which can be driven by a handwheel.
3. Selection of electric mode:
a. Firstly, determine the type of electric device: switch type multi turn electric device, switch type partial turn electric device; Adjustable multi turn electrical installation, adjustable partial turn electrical installation, electric angular stroke actuator, electric linear stroke actuator.
b. Switch type electrical equipment is used for fully open and fully closed shut-off valves. Switch type multi turn electrical installation for gate valves, knife gate valves, and globe valves; Butterfly valves and ball valves use switch type partial rotary electrical installations, but when the butterfly valve specification is DN800, a multi rotary electrical installation+worm gear box drive method is used. The switch type electrical device outputs on/off power signals, which can be remotely and centrally controlled. Switch type electrical installations generally have manual functions.
c. Adjustable electric devices are used for regulating valves that require continuous adjustment of medium flow. The opening and closing components of the electric device control valve can stay at any position of the stroke. Adjustable multi turn electrical installation for knife gate valves and throttle valves; Butterfly valves and ball valves are equipped with regulating partial rotary electrical installations; The air damper and flue butterfly valve use electric angular stroke actuators; Electric linear actuator for single and double seat regulating valves.
The control methods for regulating electrical installations include:
Proportional adjustment type input analog control signal, closed-loop control, automatic adjustment;
When the remote control type receives a continuous contact signal input, the electrical equipment will continue to operate; The signal disappears and the electrical equipment stops running. The valve opening and closing components can be controlled at any position and output position feedback signals for open-loop control.
Various types of regulating electrical devices are terminal actuators that require users to equip themselves with control instrument systems or computer control systems.
When ordering electric valves, users should pay attention to whether the power parameters, installation method, output torque, stroke, control signal, protection level, explosion-proof level and other performance meet your requirements.
Before installing and wiring electric valves, carefully read the user manual and operate according to the instructions.
4. Selection of pneumatic mode:
a. Firstly, determine the type of pneumatic device: switch type pneumatic device, regulating type pneumatic device.
b. Determine the structure of the pneumatic device: single cylinder single action, single cylinder double action, double cylinder single action, double cylinder double action.
c. Gate valves, knife gate valves, and globe valves use switch type pneumatic direct drive opening and closing components installed vertically by cylinders, generally used for opening and closing. Butterfly valves and ball valves use a horizontal cylinder to push the fork or rack to drive the opening and closing components 90. The rotating part of the rotary valve can be used for opening and closing, and can also be equipped with a locator to become a regulating valve.
d. Pneumatic devices are usually designed with modular blocks, which can be assembled into various performance switch type and regulating type pneumatic devices according to the working conditions.
e. The commonly used modular components include: electromagnetic directional valve, signal box, locator, manual mechanism, pressure storage tank, and air source triple piece, etc. Users can choose according to their working conditions.
e. The normal operation of pneumatic valves requires a gas source pressure of 0.4 "0.6 MPa. If users have special requirements for gas source pressure, they should be specified in the contract.
f. Before installing and using pneumatic valves, carefully read the user manual and operate according to the instructions.
5. Selection of hydraulic mode:
a. The hydraulic methods include cylinder direct stroke drive type, 90 degree rotating heavy hammer type, 90 degree rotating accumulator type, and electro-hydraulic push rod type.
b. Electro hydraulic push rod is an electromechanical hydraulic integrated device. Other hydraulic stations with various hydraulic modes can be designed and manufactured as a whole with drive cylinders and valves, or they can be manufactured separately from valves and installed separately. Users can choose according to their on-site needs.
c. Gate valves, gates, knife gate valves, and globe valves can be selected from hydraulic cylinder direct stroke drive type or electro-hydraulic push rod type; Butterfly valves and ball valves should be of the 90 degree rotating heavy hammer type or accumulator type, or they can be driven by electro-hydraulic push rods.
d. The installation of hydraulic valves should follow the requirements of the user manual, and debugging should be guided by the manufacturer's technical personnel on site.
