PP Processing Electric Square Air Valve

Product Model	PP board welded rectangular electric multi-leaf valve
Category	PP Machined Products
Reference Price	Price on request

Hot Customizable for Working Conditions 10 Technical Parameters

Product Overview

The PP processed electric square damper is an automatic square air damper composed of an electric actuator assembled onto a rectangular valve body welded from PP boards, driving multiple valve leaves to operate in unison. Its valve body and multi-leaf linkage structure are identical to those of manual square dampers, with the difference being the use of an electric actuator instead of a handle. After the control system issues an electrical signal, the actuator drives the main valve shaft to rotate, which, through a crank-connecting rod mechanism, synchronizes the opening or closing of all valve leaves, achieving remote automatic start and stop of rectangular air ducts.

Rectangular air ducts are widely used in equipment interfaces, fume hood exhausts, and wall-mounted or ceiling-mounted exhaust branch pipes. When these areas require automatic start/stop with equipment, zoning control, or unattended operation, electric square dampers must be used. The damper is linked with fans and production equipment, automatically opening corresponding branch valves when equipment starts and closing them when it stops, preventing short-circuit suction in non-operating branches and ensuring effective exhaust volume. Ordinary PP valve bodies are acid and alkali resistant, making them suitable for rectangular exhaust applications with moderate corrosivity and no special flammability requirements.

Xicheng Environmental can process PP electric square dampers according to the cross-sectional dimensions of rectangular air ducts. The number of valve leaves is determined by the valve height, and they are equipped with switching or regulating type electric actuators with valve position feedback. The square flange is matched with rectangular air ducts. For indoor and suspended ceiling applications with flammability requirements, the same product made of flame-retardant PP material can be selected.

Working Principle

The electric square damper works by coordinating the electric actuator and the multi-leaf linkage mechanism. After receiving a switching electrical signal, the motor in the actuator drives the output shaft to rotate approximately 90 degrees. The output shaft is connected to the valve shaft of the main valve leaf. The crank at the end of the main valve shaft is driven by a vertical connecting rod to move the cranks at the ends of the other valve shafts, forming a parallel four-bar linkage mechanism, ensuring all valve leaves rotate at the same angle synchronously to open or close the rectangular cross-section.

The multi-leaf linkage evenly distributes the rotational motion of the actuator to multiple narrow valve leaves, with each valve leaf rotating only its small area of blade, resulting in low stress and good synchronization. After the actuator reaches its position, an internal limit stops it and outputs a switch position signal. The PP valve body and valve leaves are resistant to acid and alkali fume corrosion and do not rust; the linkage pins and bushings are made of corrosion-resistant materials to ensure smooth operation of the multi-leaf mechanism in corrosive environments. When the valve leaves close, their edges overlap, reducing air leakage, and a soft sealing strip can be added for airtightness.

Structural Composition

The electric square damper consists of a PP rectangular valve body, multiple valve leaves, valve shafts, crank-connecting rod linkage mechanism, electric actuator, actuator bracket, and square flange. The valve body is formed by folding and welding PP boards into a square frame and reinforced. The valve leaves are narrow, long PP board strips arranged parallel along the valve height, each fixed to the valve shaft, with both ends of the shaft supported on the side walls of the valve body.

Each valve shaft extends outward on the same side and is equipped with a crank, connected by connecting rods for synchronization. One end of the main valve shaft is connected to the electric actuator via a coupling, which is supported by a bracket fixed to the side of the valve body. The actuator contains a motor, reduction gears, limit switches, and feedback mechanisms and can be manually reset. The valve body has square PP flanges at both ends, and sealing strips can be embedded at the edges and ends of the valve leaves. For large cross-sectional area dampers, the actuator torque must overcome the total aerodynamic moment of multiple valve leaves, so a safety margin should be considered during selection.

Specification Model Table

The following table provides a comparison between electric square dampers and manual square dampers, with cross-sectional dimensions matched to rectangular air ducts.

Item	Electric Square Damper	Manual Square Damper
Drive	Remote actuator	On-site handle
Control	Interlocked automatic	Manual adjustment
Application	Equipment linked branches	Fixed airflow balancing
Feedback	With valve position signal	None

Product Features

The PP processed electric square damper features multi-leaf synchronization and remote interlocking, making it a common valve for automatic corrosion-resistant rectangular exhaust automation. Its main features are as follows.

PP welded rectangular valve body, resistant to acid and alkali fume corrosion
Electric actuator drives multi-leaf linkage for synchronized opening
Remote switching and linked with equipment fans, saving labor
Automatic valve closure during shutdown, preventing short-circuit suction and backflow
Narrow valve leaves with low stress, ensuring reliable operation even in large cross-sections
With valve position feedback, operational status can be monitored
Square flange matched with rectangular air ducts, dimensions customizable

Body Material	PP Sheet
Processing Technology	Panel welding assembly
Section Shape	rect
Valve Leaf Form	Multi-leaf linkage
Drive Type	Electric Actuator
Control Type	Switching / Regulating Option Available
Corrosion resistance performance	Acid-alkali-resistant
Connection Method	Square Flange
Feedback Signal	Valve Position Feedback
Specifications and Features	Non-standard custom section size

Application Industries

Branch electric valves for multiple rectangular exhaust units sharing a fan
Rectangular exhaust along the edge of electroplating automatic lines controlled by equipment operation
Interlocked electric square dampers for rectangular exhaust ports of production equipment
Centralized exhaust branch electric switches for laboratory fume hoods
Remote isolation valves for rectangular exhaust dry pipes in workshop zones
Electric isolation dampers for rectangular inlets/exhausts of purification equipment
Rectangular corrosion-resistant exhaust electric valves for unattended areas

Typical Process Locations

The electric square dampers are installed at the connection points between rectangular ducts and equipment, fans, or dry pipes. The most typical scenario is when multiple exhaust units share a single fan, with each unit equipped with an electric square damper at its rectangular exhaust port. These dampers are interlocked with equipment operation signals: they open when the equipment runs and close when it stops, concentrating airflow to the operating units. The square flanges of the dampers align with the rectangular ducts, with actuators oriented toward maintenance access and power control wiring reserved.

When integrated with control systems, the on-off square dampers are controlled by PLC outputs or relay outputs from control cabinets. Position feedback contacts report valve status, enabling sequential interlocking with fan start/stop operations: the fan starts after the valve fully opens, and the valve closes after the fan stops. During commissioning, manual rotation checks ensure smooth and synchronized multi-leaf linkage operation. Power-on testing verifies full open/close angles and feedback signals, confirming that the valve leaves close with proper alignment and minimal gaps.

This is a multi-leaf actuator linkage failure. First, check if the fixed screws of the valve shaft crank for the non-moving leaf are loose, if the connecting rod pins are dislodged or worn, or if the valve shaft is jammed by dust or foreign objects. Re-tighten the cranks and pins, align all valve leaves to the same reference angle before connecting the linkage rod, clean the jammed areas, and apply appropriate lubrication at the bushings. After treatment, power on or manually operate the entire set of valve leaves to observe if they move synchronously from fully closed to fully open and if the overlap is consistent. Do not assume the valve is functioning properly just by observing the actuator's movement. If individual leaves still fail to move synchronously, check if the valve shaft of that leaf is bent or if the shaft seat is deformed. Daily inspections should focus on the synchronicity and positioning of the valve leaves, addressing any issues promptly by shutting down the equipment to ensure accurate airflow regulation in each branch.

Depends on the total torque of the vane assembly. The aerodynamic torque of each vane in the multi-vane valve is Summary ed to the active vane shaft via linkages; the larger the cross-section, the more vanes, and the higher the wind speed, the greater the total torque. If the total torque falls within the rated torque range of a single actuator with a margin, one actuator is sufficient; for excessive torque, a high-torque actuator can be selected, or the valve can be divided into two groups, each equipped with one actuator for synchronized control. When selecting, provide the cross-sectional dimensions and wind pressure; the manufacturer calculates the torque, and actuators should not be matched based solely on experience with small valves.

Ceiling plenums and indoor fire compartments typically require fire-resistant duct materials. Standard PP lacks fire resistance and should be replaced with fire-resistant PP electric square dampers and fire-resistant rectangular ducts, meeting the fire code's material combustion performance requirements. Standard PP electric square dampers are more suitable for outdoor, open workshops, or corrosive exhaust applications without fire resistance requirements. Whether fire-resistant materials must be used depends on the building fire design, duct installation location, and local review requirements. Material selection should not solely consider corrosion resistance. Dampers installed in ceilings, pipe shafts, vertical shafts, and high-traffic areas should generally be configured with fire resistance. When ordering, specify the material and fire resistance grade in the list and request a test report to prevent the use of standard materials as substitutes for fire-resistant products on-site.

First, confirm whether the actuator has reached the fully closed position and whether the limit is correct, then check if all vanes are synchronized, if the edge sealing strips have fallen off or aged, and if there are any Miscellaneous items stuck between the vanes or between the vanes and the side walls. When the multi-vane valve is closed, the edges of the vanes should interlock with each other and make contact with the side wall. Adjusting the length of the linkages can correct the closing angle of the vanes. For applications requiring high gas tightness, directly order the sealed electric multi-vane valve equipped with circumferential sealing strips and side sealing. Ordinary electric square valves are primarily used for on-off and regulation, and do not guarantee zero leakage.

Interlock the open position signal of each electric square valve with the fan start circuit: after issuing the startup command, open the corresponding electric valve first, then start the fan upon receiving the open position feedback; during shutdown, stop the fan first, then close the valve. When multiple devices share a fan, the control system opens the corresponding branch valves based on the number of operating devices and required airflow, and may link to variable frequency speed regulation when necessary. The interlocking logic is implemented by PLC or relay; it is strictly prohibited to run the fan for extended periods with all valves closed to avoid pressure buildup in the duct that may damage the equipment.

For custom electric square butterfly valves, provide the following information: rectangular valve body cross-sectional dimensions (width x height), square flange dimensions and hole positions, number of vane plates, actuator type (on/off or regulating), power voltage, control and feedback signal format, protection rating, whether a power failure reset is required and the reset direction, material (standard PP or PP flame retardant), seal strip requirements, duct air pressure, and medium temperature. Also provide equipment interlock control requirements and electrical interface diagrams to facilitate actuator wiring and system matching. For installations within suspended ceilings, specify the maintenance port location and actuator orientation. For outdoor or damp locations, indicate protection and rainproofing requirements. Complete parameters and clear control logic are necessary for the manufacturer to configure actuator torque, limit switches, and feedback components, ensuring both electrical and mechanical alignment upon valve delivery.

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