PP Fire-Resistant Electric Damper

Product Model	PPs Formed Electric Air Valve
Category	PP Machined Products
Reference Price	Price on request

Hot Customizable for Working Conditions 10 Technical Parameters

Product Overview

The PP Flame-Retardant Electric Damper is a standard-sized automatic air damper equipped with an electric actuator, assembled onto a flame-retardant PP injection-molded valve body. Compared to plate-welded electric dampers, the molded valve body features standardized dimensions, uniform wall thickness, fast delivery, and cost-effectiveness, making it suitable for indoor corrosion-resistant exhaust duct sections within standard series sizes. Upon receiving an on/off electrical signal, the actuator drives the vane to rotate approximately 90 degrees, enabling remote automatic opening/closing of the air duct and interlocking control with fans and equipment.

The flame-retardant PPs valve body is resistant to acid and alkali gas corrosion and exhibits self-extinguishing properties, making it ideal for corrosion-resistant exhaust systems installed indoors, suspended ceilings, and pipe shafts. Electric dampers are commonly used in exhaust branch pipes requiring automatic on/off operation with production equipment, interlocking dampers at fan inlets/outlets, and remote isolation dampers in unattended areas, eliminating the need for operators to manually switch valves on-site, thereby enhancing the automation level of exhaust systems and preventing gas backflow during shutdown.

The PP flame-retardant electric dampers supplied by Xicheng Environmental Protection are standard round-shaped openings, compatible with PPs molded ducts, and connected via slip-fit or flange joints. They are equipped with on/off electric actuators featuring full-open/full-close position feedback, and the actuators can include a manual operation knob. For applications requiring continuous airflow regulation, analog modulating dampers should be selected. For large diameters or non-standard sizes, plate-welded electric dampers are recommended.

Working Principle

In an on/off electric damper, the motor inside the actuator drives the output shaft to rotate between 0 and 90 degrees via a reduction gear. The output shaft, connected via a coupling, synchronizes the rotation of the vane shaft. When the control system issues an open valve signal, the motor drives the vane to the fully open position, at which point an internal limit switch disconnects power and sends an open On-site signal. Conversely, a close valve signal reverses the rotation to the fully closed position. When fully open, the vane aligns parallel to the airflow, minimizing resistance, and when fully closed, it aligns perpendicular to the airflow, sealing the duct.

The corrosion-resistant and flame-retardant performance of the molded PPs valve body and vane is inherent to the material. The vane rotates without rusting or seizing in acid and alkali gases, and the material self-extinguishes without spreading along the pipeline upon ignition. The actuator is installed on the outside of the valve body, isolated from the internal gas stream via a valve shaft seal. A seal ring and wear-resistant bushing are provided between the valve shaft and the valve body's shaft seat, reducing air leakage through the shaft hole while ensuring smooth vane rotation. Actuator torque is selected based on the vane's operating torque under maximum air pressure, with a safety margin added.

Structural Components

The flame-retardant electric damper consists of a PPs molded valve body, vane, shaft, shaft seat seal, electric actuator, mounting bracket, and end connections. The valve body is an injection-molded cylindrical structure with slip-fit or flange ends for compatibility with molded ducts. The vane is a molded circular plate fixed to the shaft, which passes through the valve body and is supported by shaft seats on both sides. The shaft seats are equipped with seal rings and bushings.

The actuator is mounted on the extending end of the shaft via a bracket, which is fixed to the outside of the valve body. The actuator's output shaft is coaxially connected to the valve shaft. The actuator integrates a motor, reduction mechanism, limit switch, feedback contacts, and manual operation mechanism. The junction box has a protection rating suitable for indoor environments. A soft seal strip can be added to the vane edge to improve full-closure air tightness. Standard dampers feature a single vane structure, covering common molded duct series sizes.

Specification Model Table

The following table provides a comparison for selecting molded and plate-welded electric dampers, with diameters matched to duct series.

Item	Molded Electric Damper	Plate-Welded Electric Damper
Diameter	Standard series	Large non-standard
Delivery	Fast, cost-effective	Drawn to print
Application	Indoor standard branch pipes	Main pipes, non-standard sections
Material	PPs Flame-Retardant	PP / PPs optional

Product Features

The PP Flame-Retardant Electric Damper is a standard molded, corrosion-resistant, and flame-retardant automatic valve, commonly used for indoor standard corrosion-resistant exhaust branch pipes. Key features include:

PPs flame-retardant molded valve body, self-extinguishing, acid/alkali resistant
Standard diameters with uniform wall thickness, fast delivery, cost-effective
Remote on/off operation via electric actuator, supports equipment interlocking
Full-open/full-close position feedback, status monitorable
Valve shaft seal reduces air leakage, vane rotates smoothly
Slip-fit or flange connections with molded ducts, quick installation
Actuator includes manual operation knob, allows adjustment and emergency use

Body Material	PPs Flame Retardant Polypropylene
Molding Process	Injection Molding
Section Shape	Round
Drive Type	Electric Actuator
Control Type	Switching Full On/Full Off
Feedback Signal	Fully open and fully close in place
Flame Retardancy Performance	Self-extinguishing
Corrosion resistance performance	Acid-alkali-resistant salt
Connection Method	`Spigot / Flange`
Manual operation	Actuator with manual knob

Application Industries

Standard branch duct electric switch valves for laboratory exhaust systems
Standard diameter exhaust synchronous electric valves for electroplating production lines
Electric valves for indoor PPs forming duct equipment interfaces
Interlocked standard diameter electric exhaust dampers for fan inlets and outlets
Remote isolation valves for corrosion-resistant exhaust branch ducts in suspended ceilings
Standard branch line electric valves for multi-machine shared fans
Standard corrosion-resistant electric exhaust valves for semiconductor plant facilities

Typical Process Locations

The flame-retardant electric dampers are installed at equipment interfaces, branch ducts, and fan inlets/outlets of indoor standard diameter PPs circular ducts, connected to forming ducts via spigot or flange. The electric valve at the equipment exhaust port operates with the equipment start/stop, while the fan inlets/outlet valves are interlocked with the fan—valves open before startup and close after shutdown. The valve position should ensure the actuator faces the maintenance side, with reserved space for power control wiring and manual operation, avoiding actuator wall contact or placement in water accumulation areas.

During electrical connection, the actuator power is interlocked with the fan or equipment control circuit, and the switch position signal is connected to the control cabinet, with the upper system displaying valve status. The commissioning sequence is: first, operate the valve vane manually without power to confirm full travel flexibility; second, power on and verify the actual vane angle matches the actuator indication at the local switch; finally, perform remote interlock and position feedback joint debugging to ensure the fan does not start when the valve is closed.

For electric valves installed on standard indoor branch pipes and equipment interfaces within the PPs formed duct standard series, choose formed electric valves. They feature standard dimensions, fast delivery, low cost, and good interchangeability. For valves with sizes outside the standard series, used on large-diameter main pipes, or requiring special lengths, special flanges, or non-standard cross-sections, select plate-welded processed electric valves. The vane can be reinforced, the valve shaft thickened, and the actuator torque selection range is wider, allowing them to withstand higher air pressure. Both types operate on the same control principle, where the actuator drives the vane movement. The main differences lie in the size coverage range, structural strength, and delivery cycle. Selection should be based on duct size, air pressure, and installation location, with priority given to processed valves for large sizes, high air pressure, and non-standard applications. It is recommended to standardize connection standards and actuator models within the same system for easier spare parts replacement, wiring, and future maintenance.

Interlocks prevent fans from starting under closed duct conditions, which can cause pressure buildup, current overload, duct collapse, and equipment damage. They also automatically close valves after fan shutdown to prevent outdoor air from infiltrating, corrosive gases from spreading in the workshop, and cold air from entering pipelines and rooms during winter. The standard interlock sequence is to open valves first during startup, then start the fan upon receiving the "fully open" signal, and to stop the fan first during shutdown, followed by delayed valve closure. When multiple branches share a fan, the control system opens the corresponding branch valves based on the number of operating units and required airflow, and may adjust fan frequency control as needed. Interlock logic is implemented by relays or programmable controllers in the control cabinet, with valve position feedback and fault alarms configured. Valve-to-fan interlocking is a fundamental requirement for exhaust automation, and the commissioning process must verify the sequence of valve opening, fan startup, fan shutdown, and valve closure, as well as timeout protection for each step.

Follow the sequence to troubleshoot: First, confirm that the power voltage matches the actuator nameplate, check if the control signal and valve opening command are present, and verify if the interlock conditions are met; then inspect if the connection between the actuator and valve stem is loose, and if the manual or electric switch is in the disengaged position; next, loosen the actuator's manual handwheel to determine if the valve disc is mechanically jammed or if the actuator itself is faulty. Mechanical jamming is often caused by dust and crystallization in the shaft seat, foreign objects stuck in the valve disc, shaft misalignment, or thermal deformation of the valve body, while electrical faults are typically related to the motor, limit switch, capacitor, or wiring issues. Do not repeatedly force power-on before identifying the cause to avoid burning out the actuator motor. After confirming the mechanical part is flexible, test the actuator with power-on alone to distinguish between mechanical and electrical faults before proceeding with repairs. After completing the repairs, perform several full open/close cycles to verify that the valve position feedback matches the actual opening degree.

Switched electric valves only have two stable positions: fully open and fully closed, and cannot be left in a mid-position for extended periods. Forcing repeated adjustments using the jogging method can cause frequent motor operation, inaccurate positioning, severe overheating, and potential motor burnout or limit switch damage. They are not suitable for continuous regulation. For applications requiring automatic control of airflow size based on sensor signals, analog control valves should be selected. The actuator can stably stop at any angle according to the control signal and feed back the actual valve position to the system, achieving closed-loop regulation. Switch valves address on/off and isolation, while regulating valves address airflow size. Their structures and control methods differ, and they should not be mixed. If the system requires both continuous regulation and tight isolation, an analog control valve can be cascaded with an electric sealed valve to separately handle regulation and isolation functions.

A standard switch valve has a designed gap between the valve disc and body, allowing a small amount of air leakage when fully closed. This is sufficient for general isolation and preventing backflow, which is a normal characteristic of regulating valves. For applications requiring high gas tightness, such as isolating hazardous gases, preventing cross-contamination, or laboratory pressure differential control, select an electrically actuated closed valve with a soft seal on the valve disc edge and an actuator with sufficient closing torque. If air leakage suddenly increases during use, check in the following order: whether the valve disc is fully closed, whether the limit and stroke are correct, whether the seal is damaged, whether the valve shaft connection is slipping, and whether there are foreign objects blocking inside the valve body. After identifying the cause, clean, adjust, or replace the seals. Do not rely solely on increasing the actuator torque to force it closed. Regularly inspect the seals and valve position during fan maintenance to ensure gas tightness during isolation.

The actuator power voltage must match the nameplate specifications. Common voltages include AC 220V and AC or DC 24V. Wiring should be performed by an electrician according to electrical drawings, ensuring proper grounding and protection. Control and feedback lines should be connected to the control cabinet and routed separately from power lines. Analog signal lines should use shielded cables with single-ended grounding. Leave sufficient cable slack for maintenance and ensure proper sealing at cable entry points. For humid and corrosive environments, select actuators with appropriate protection ratings and apply anti-corrosion treatments or install protective covers. Cable entry points should prevent corrosive gases and moisture from entering the junction box. Commissioning should follow the sequence of manual operation first, then electric operation. Limit switches are pre-adjusted at the factory and should not be altered arbitrarily. Valves that remain non-operational for extended periods should be powered on periodically to check the motor, limit switches, and valve shaft, preventing jamming due to prolonged inactivity.

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