Practical Concise Guide for Converting Manual Gate Valves to Electric Operation

I. Core Transformation Principle and Retrofit Difficulty

II. Pre-transformation Model Selection and Configuration Preparation

1.Key Points for Electric Actuator Selection

• Match valve parameters: Select corresponding brackets and coupling sleeves based on the gate valve’s DN nominal diameter, pressure class and rising/non-rising stem type;
• Reserve torque margin: Select torque according to medium resistance with a 1.2–1.5 times margin to prevent motor burnout caused by overload during pressure-bearing opening and closing;
• Adapt to working conditions: Choose ValenTech electric actuators with corresponding protection grades for outdoor, humid, dusty and explosion-proof environments to fit various harsh industrial scenarios.

2.Power Supply and Control System

• Basic electric control: Only local valve opening/closing is needed; wire with matching voltage, featuring low cost and simple construction;
• Full automatic control: For remote operation, PLC linkage and automatic regulation, install 485 communication and analog signal modules to connect to the automatic control system. Actuators from ValenTech come with standardized communication interfaces for convenient networking without extra reconstruction.

III. Standardized Construction Procedures

1. Shutdown, pressure relief and safety protection: Close the upstream main valve, drain all media to relieve pressure and cool down, cut off on-site power and hang warning signs. Construction with pressure, media or live electricity is strictly prohibited.
2. Dismantle manual components and clean the valve stem: Remove handwheels and manual transmission parts; clear rust and debris on the valve stem to ensure a smooth, undeformed stem for subsequent installation.
3. Install brackets and actuators (critical process): Assemble customized brackets and coupling sleeves, align the actuator with the valve stem, calibrate horizontal and vertical levels to guarantee full concentricity without offset or tilt, and evenly fasten all bolts to avoid shaking, eccentric wear and coupling detachment during operation. The complete set of supporting coupling brackets from ValenTech features built-in positioning scales to save time on concentricity calibration.
4. Standard wiring and circuit inspection: Distinguish power cables, control cables and signal feedback cables, apply waterproof and insulation treatment to all wires, and conduct full insulation testing after wiring to eliminate short circuits and electric leakage.
5. Adjust limit travel and overload protection: Conduct low-speed power-on trial run, accurately calibrate opening and closing limits to prevent valve stem damage and sealing leakage from overtravel; adjust torque overload protection to enable automatic shutdown under excessive resistance to protect equipment.
6. Pressure test and overall acceptance: Boost pipeline pressure slowly, perform full opening and closing cycles 5–10 times repeatedly, inspect smooth operation, abnormal jamming, leakage at valve body and connecting parts, and accurate signal feedback. Acceptance is passed if all indicators are normal.

IV. Operation Specifications After Retrofit

1.Conventional electric operation

2.Manual emergency operation during power failure

V. Exclusive Precautions for Gate Valve Retrofit

1. Handwheels and transmission mechanisms shall not be used as lifting points; avoid impact and collision on transmission components.
2. Double wedge gate valves must be installed vertically with vertical valve stems and top-mounted handwheels; tilted or inverted installation is forbidden to prevent jamming and sealing failure.
3. For gate valves equipped with bypass valves, open the bypass valve first to balance inlet and outlet pressure differences before formal opening, reducing opening and closing resistance.
4. The electric gate valve is only for full flow or full cut-off of media; half-open throttling is strictly prohibited to avoid sealing surface erosion and subsequent leakage.
5. Only use the original factory hand crank for manual operation; auxiliary levers for forced opening/closing are forbidden. Shut down for maintenance of sealing surfaces and valve stems if jamming or leakage occurs.
6. Fully lubricate valve stems, couplings and transmission components at least once a month for frequently operated electric gate valves.
7. Follow the official product manual for all installation, commissioning and maintenance work to avoid equipment malfunctions caused by non-standard operations.

VI. Summary