Transformation plan for manual valve to electric gate valve

The closing principle of this renovation plan is to rely on electric thrust to rotate the valve stem, so that the sealing surface of the valve disc is tightly adhered to the sealing surface of the valve seat, preventing the circulation of the medium.

Let's first understand the principle of a gate valve: The closing principle of a gate valve is to rely on electric thrust to rotate the valve stem, so that the sealing surface of the valve disc is tightly adhered to the sealing surface of the valve seat, preventing the flow of the medium.

After understanding the principle, it is necessary to choose a multi turn actuator, which is called a multi turn actuator.

Manual valve to electric gate valve renovation plan:

Determine the control mode of the electric actuator according to the production process control requirements

The control modes of electric actuators are generally divided into two categories: switch type (open-loop control) and regulating type (closed-loop control).

1. Switch type (open-loop control)

Switch type electric actuators generally control the opening or closing of valves, which are either in the fully open position or the fully closed position. Such valves do not require precise control of the medium flow rate.

It is worth mentioning that switch type electric actuators can be divided into separate structures and integrated structures due to their different structural forms. When selecting, it is necessary to provide an explanation for this, otherwise mismatches such as conflicts with the control system often occur during on-site installation.

a) Split structure (usually referred to as ordinary type): The control unit is separated from the electric actuator, and the electric actuator cannot control the valve alone. An external control unit must be added to achieve control. Generally, a controller or control cabinet is used for external matching.

The disadvantage of this structure is that it is not convenient for the overall installation of the system, increases wiring and installation costs, and is prone to faults. When faults occur, it is not easy to diagnose and repair, and the cost-effectiveness is not ideal.

b) Integrated structure (usually referred to as integrated type): The control unit and electric actuator are packaged into one unit, which can be operated locally without the need for an external control unit. Remote operation only requires outputting relevant control information.

The advantage of this structure is that it facilitates the overall installation of the system, reduces wiring and installation costs, and is easy to diagnose and troubleshoot. However, traditional integrated structural products also have many imperfections, which has led to the emergence of intelligent electric actuators. We will elaborate on intelligent electric actuators later.

2. Regulating type (closed-loop control)

The regulating electric actuator not only has the function of a switch type integrated structure, but also can precisely control the valve, thereby accurately adjusting the medium flow rate. Due to limited space, its working principle will not be explained in detail here. Below is a brief explanation of the parameters that need to be noted when selecting adjustable electric actuators.

a) Control signal type (current, voltage)

The control signals for regulating electric actuators generally include current signals (4-20mA, 0-10mA) or voltage signals (0-5V, 1-5V). When selecting, it is necessary to clarify the type and parameters of the control signal.

b) Work form (electrically open type, electrically closed type)

The working mode of regulating electric actuators is generally electric open type (taking 4-20mA control as an example, electric open type refers to 4mA signal corresponding to valve closing, 20mA corresponding to valve opening), and the other type is electric close type (taking 4-20mA control as an example, electric open type refers to 4mA signal corresponding to valve opening, 20mA corresponding to valve closing). In general, the selection requires a clear understanding of the working form, and many products cannot be modified after leaving the factory. The intelligent electric actuators produced by Ogilvy Valve Control can be modified at any time through on-site settings.

c) Signal loss protection

Signal loss protection refers to the electric actuator opening and closing the control valve to the set protection value when the control signal is lost due to faults in the circuit, etc. The common protection values are fully open, fully closed, and in place, and are not easy to modify after leaving the factory.