PP Fire-Retardant Process Damper

Product Model	PPs plate-welded round manual air valve
Category	PP Machined Products
Reference Price	Price on request

Hot Customizable for Working Conditions 11 Technical Parameters

Product Overview

The PPs flame-retardant processing damper is a circular manual air volume regulating damper made by processing the valve body of PPs flame-retardant sheet material through roll welding. Its structural form is the same as that of a general PP processing damper, with the difference being that the valve body, valve plate, and welding rod are all made of flame-retardant PPs material. This retains the acid and alkali corrosion resistance advantages of polypropylene while also possessing flame-retardant self-extinguishing properties. It is primarily used for large-diameter circular corrosion-resistant air ducts in indoor exposed installations, suspended ceilings, and locations requiring fire inspection approval.

While general PP air duct dampers are corrosion-resistant, the material is flammable, posing a fire spread risk when used indoors or in fire compartments. The PPs flame-retardant plate is enhanced with flame-retardant additives, making the sheet difficult to sustain combustion when exposed to open flames and self-extinguishing after the fire source is removed. The damper, as a component on the pipeline, is matched with flame-retardant air ducts to ensure the flame-retardant continuity of the entire corrosion-resistant ventilation system, meeting the fire requirements of indoor corrosion-resistant exhaust engineering.

The PPs flame-retardant damper processed by Xicheng Environmental Protection has a plate-welded circular structure. The valve plate can be reinforced, and large-diameter models are equipped with worm gear mechanisms. The ends can be connected via flanges or socket connections, with the valve plate edge optionally fitted with a sealing strip. The diameter, wall thickness, and length are not limited by molds and can be produced according to drawings to match PPs flame-retardant processing air ducts, making it suitable for exhaust systems in industries such as chemical processing, electroplating, laboratories, and semiconductor manufacturing that require both corrosion resistance and fire protection.

Working Principle

The air volume regulation principle of the flame-retardant processing damper is the same as that of a general circular damper. Turning the handle or wheel drives the valve plate to rotate within the valve body, changing the flow cross-section and local resistance to achieve air volume regulation and actuation. Large-diameter valves use worm gear reduction for effortless operation with self-locking functionality. The reinforced valve plate structure resists airflow pulsation and prevents noise caused by vibration at small openings.

Flame retardancy is the core feature of this product. The flame-retardant components in the PPs sheet suppress flame propagation during combustion, causing the flame to self-extinguish after the ignition source is removed, preventing the damper and connected air ducts from becoming pathways for fire spread. The valve plate, valve body, welding rod, and sealing components are all matched with flame-retardant or non-flammable materials to prevent any non-flame-retardant parts from creating flame paths. In terms of corrosion resistance, PPs retains the chemical stability of polypropylene against acid, alkali, and salt exhaust gases, ensuring no rust or sticking in long-term use in corrosive environments.

Structural Composition

The flame-retardant processing damper consists of a PPs plate-welded valve body, flame-retardant valve plate, valve shaft, shaft seat, operating mechanism, and flanges. The valve body is formed by rolling PPs sheet and welding, with longitudinal seams welded using PPs flame-retardant electrodes. The valve plate is a PPs circular plate, with large-diameter valve plates welded with reinforcing ribs or constructed as a double-layer structure. The valve shaft passes through the valve body, with both ends fixed to the outside of the valve body and sealed.

The operating mechanism uses a locked handle for small diameters and a worm gear wheel mechanism for large diameters, with the valve plate edge optionally fitted with a corrosion-resistant and flame-retardant soft sealing strip. The valve body ends are welded with PPs flanges or formed into sockets, with flanges drilled according to air duct standards. Corrosion-resistant metal or coated components are used for the valve shaft, pins, and other load-bearing parts. The shaft sleeve is made of self-lubricating corrosion-resistant material to ensure smooth operation in flame-retardant environments. For automated control, the valve body can be equipped with an electric actuator.

Specification Model Table

The following table compares the flame-retardant damper with the general PP damper. Specific diameters are determined based on air duct design.

Item	PPs Flame-Retardant Damper	General PP Damper
Flame Retardancy	Self-extinguishing	Not applicable
Corrosion Resistance	Acid, alkali, salt resistant	Acid, alkali, salt resistant
Applicable Locations	Fire compartments indoors	Outdoor or no requirements
Processing Method	Plate-welded non-standard	Plate-welded / Formed

Product Features

The PPs flame-retardant processing damper integrates corrosion resistance, flame retardancy, and large-diameter customization, making it a specialized regulating valve for indoor corrosion-resistant exhaust trunk pipes. Its main features are as follows.

PPs flame-retardant sheet roll-welded, self-extinguishing, meets fire requirements
Corrosion-resistant to acid, alkali, salt, no sticking in corrosive gases
Full flame-retardant matching for valve body, valve plate, and welding rod, no flame paths
Large-diameter valve plate reinforced with worm gear, effortless and vibration-free
Non-standard diameter, wall thickness, and length, compatible with flame-retardant air ducts
Flange socket connection, optional soft seal, easy installation
Can be retrofitted with electric actuators for automated control needs

Body Material	PPs Flame Retardant Board Material
Welding Electrode Material	PPsFlame-RetardantWeldingElectrode
Processing Technology	Roll Plate Welding Assembly
Section Shape	Round
Flame Retardancy	Self-extinguishing
Corrosion resistance performance	Acid-alkali-resistant
Drive Type	Handle / Worm Gear Manual
Connection method	Flange / Butt-welding
Specifications and Features	Large-diameter custom non-standard
Valve Disc Structure	Single-piece reinforced stiffening
Sealing Options	Soft Seal Option Available

Application Industries

Large-diameter corrosion-resistant exhaust dry pipe valves for chemical plant indoor ventilation
Round flame-retardant air duct dampers for fire-rated areas in electroplating workshops
Corrosion-resistant exhaust dry pipe regulating valves for semiconductor and panel factories
Indoor round duct section dampers for laboratory exhaust systems
Corrosion-resistant air dampers with fire protection requirements for suspended ceilings and pipe galleries
Corrosion-resistant exhaust vertical shaft inlet valves for high-rise buildings
Full system valves compatible with PPs flame-retardant air ducts

Typical Process Locations

Flame-retardant processing dampers are installed on circular PPs flame-retardant air ducts indoors, in suspended ceilings, in pipe galleries, and within fire-rated areas. They are used in conjunction with flame-retardant air ducts and flame-retardant fittings to ensure consistent flame retardancy levels across the pipeline system. On pipelines passing through fire-rated areas, damper locations must be coordinated with fire dampers or fire sealing according to fire protection design. Plastic flame-retardant dampers cannot replace fire protection dampers specifically designed for fire protection. Dry pipe valves are used for regional airflow regulation and maintenance isolation.

Installation methods are the same as those for standard plate-welded round valves. The valve body is coaxial with the air duct, with flange fastening and sealing. A heavy-duty worm gear mechanism is supported by an independent bracket, with the operating handle oriented toward the maintenance access channel. During acceptance, in addition to checking the airflow regulation function, the material flame retardancy certification must be verified to ensure consistency with the air duct system. For indoor dry pipes requiring remote control, an electric actuator can be installed on the same flame-retardant valve body, with proper fire protection for the actuator.

No. The function of PPs fire-rated dampers is to regulate airflow and isolate ventilation pipes, while fire self-extinguishing only indicates that the material itself is not easily combustible. It does not have fire protection functions such as temperature-sensitive melting, automatic closing, and fire integrity. According to fire protection codes, fire-certified fire dampers or smoke exhaust dampers must be installed where ducts penetrate fire compartments, machine rooms, and floor slabs. Fire-rated dampers only address the fire resistance of plastic pipes themselves and cannot be mutually replaced. Fire dampers must be installed at penetration points in accordance with building fire protection codes, and must pass construction drawing review and fire inspection.

When ordering, clearly specify the requirement for flame-retardant PPs material and agree on the flame-retardant grade. Request the manufacturer to provide the flammability test report for the corresponding batch of sheets. If necessary, conduct oxygen index or vertical burning tests according to standards. On-site verification can be performed through sheet markings and quality certificates. Flame-retardant PPs sheets and ordinary PP sheets have similar appearances, making them difficult to distinguish by the naked eye. Relying on methods like burning smell for identification is unreliable. For critical projects, clearly state material standards and acceptance criteria in the contract to prevent the substitution of ordinary PP for flame-retardant sheets.

Outdoor suspended ducts have a relatively low risk of fire spread, and the use of flame-retardant materials primarily depends on local fire codes, building spacing, and owner requirements. However, ducts in indoor spaces, suspended ceilings, crowded areas, and fire compartments typically require the use of flame-retardant materials. The main issues for outdoor ducts are ultraviolet degradation and temperature resistance; UV-resistant panels or sun shading and painting treatments should be selected to slow down plastic aging. For systems connecting indoors and outdoors, the pipe sections entering the building should comply with indoor requirements, using PP flame-retardant dampers and ducts. It is not acceptable to use standard materials for the entire pipeline just because the initial section is outdoors. When selecting materials, determine them based on the actual installation location of the dampers: outdoor sections should prioritize weather resistance, while indoor sections should prioritize flame retardancy. Fireproof sealing and fire dampers must be used when passing through building exterior walls and fire compartments.

Do not mix. The welds of fire-resistant air dampers and fire-resistant air ducts must use PPs fire-resistant welding electrodes to ensure that the welds match the fire resistance level of the base material, with no fire-resistant weak points in the entire pipeline. If ordinary PP welding electrodes are used to weld fire-resistant panels, the welds become fire-resistant breaks on the pipeline. During a fire, the welds may melt and crack first, leading to pipeline failure and failing fire inspection. During processing, ensure that the plates, valve plates, welding electrodes, and flanges are all made of the same fire-resistant compatible material. Sealing materials should also be selected as fire-resistant or flame-retardant materials. On-site, store fire-resistant welding electrodes and ordinary welding electrodes separately with clear markings to prevent workers from picking up the wrong ones. After welding, verify the welding electrode packaging and material certification to ensure that the weld areas have the same self-extinguishing properties as the base material.

Conventional flame-retardant PP boards are made by adding flame-retardant components to polypropylene, with the main material still being polypropylene. Their corrosion resistance to common acids, alkalis, and salt gases is comparable to that of standard PP, meeting conventional corrosion-resistant ventilation requirements. However, the added components may affect the material's tolerance to certain strong oxidizing media or special solvents. When encountering chromic acid mist, concentrated nitric acid, strong oxidizing agents, or special organic substances, the medium composition, concentration, and temperature should be actively specified. Material selection should be made by the manufacturer or based on corrosion resistance data, and corrosion compatibility tests may be required when necessary. It should not be assumed that flame-retardant materials are inherently resistant to all media. For conventional acid-alkali ventilation, they can be used with confidence. For complex compositions or strong oxidizing conditions, the corrosion resistance table should be checked or a more corrosion-resistant material should be used to ensure the valve remains corrosion-free over the long term.

In addition to providing conventional parameters such as size, wall thickness, connection method, operating mechanism, and air pressure, it is essential to clarify the flame retardancy grade of materials and applicable standards, as well as the flame retardancy matching requirements for welding rods and seals, and to request a material test report. Valves and PP flame retardant ducts should ideally be supplied by the same manufacturer to avoid inconsistencies in flange standards and material batches. For indoor installation, verify the valve length, operating orientation, and maintenance space, and confirm with the design team in advance whether additional fire dampers are required for fire-related sections to prevent rework.

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