Custom PP duct sections are polypropylene ventilation pipes made to order for projects that need non-standard sizes, lengths, colors or connections. They are produced from PP sheet welding with flange reinforcement, in standard polypropylene (PP) or flame retardant PPs, in beige or grey. Sizes are customized to your duct schedule, and sections are supplied in 3 m lengths or in lengths confirmed per project.

Because the duct is made to order, it is a good fit when a standard catalog size does not match the duct run, or when material grade, color or connection detail must be specified for a particular project. The XICHENG standard range covers sizes from φ20 mm to φ500 mm; custom ducts extend that range with dimensions confirmed against your drawings. For standard sizes within the catalog range, see Polypropylene Round Ducts.

A custom duct is one part of a ventilation system: it connects to fans, fittings and airflow dampers rather than replacing them, and matching elbows, tees, reducers, flanges and dampers are available from the same supplier, so a complete PP duct line can be specified from one source.

Product Selection Summary

Good Fit

• Projects needing non-standard duct diameters, wall thicknesses or section lengths
• Specific material (PP or flame retardant PPs) or color (beige, grey) requirements
• Duct runs calling for collar or flange connections
• Engineering and OEM projects where dimensions are confirmed from drawings before manufacture

Conditions To Confirm

• Gas composition, concentration, temperature and moisture at the actual operating point
• Required diameter, wall thickness, section length and quantity
• Material grade: PP or flame retardant PPs (specify grade when fire-rated ductwork is required)
• Color (beige or grey) and connection method (collar or flange) for each joint
• Available static pressure and airflow schedule

Not a Replacement For

• Fans, airflow balancing devices, room controls or gas treatment equipment

Technical Specifications

Confirmed Product Parameters

Because every section is made to order, all dimensions above are confirmed per project – see Customization Options below for what can be specified, and the selection notes for the information to include with your inquiry.

Customization Options

What Can Be Customized

• Size: diameter, wall thickness and section length are confirmed per project against your duct schedule and drawings. Non-standard sizes are the main reason customers choose a custom duct over a catalog section.
• Material: standard PP or PPs flame retardant grade. Specify the required flame retardant grade when fire-rated ductwork is needed.
• Color: beige or grey, selected per project.
• Connection: collar connection or flange connection, selected per joint to match the rest of the duct run.
• Reinforcement: flange welding is applied where the duct body needs extra support, including large-diameter sections.

Why Order Custom

Catalog sizes do not always match an existing duct layout or a retrofit run. A custom duct lets the section dimensions, material grade, color and connection detail be specified to the project – engineering and OEM projects often supply their own drawings and require ducts made to those drawings. Custom sections also let a facility standardize on one non-catalog diameter across a complete system.

How Custom Orders Are Confirmed

Send your duct schedule and drawings with the inquiry. Each section is confirmed with approved dimensions, wall thickness and connection detail before manufacture, so the delivered duct matches the design. MOQ and lead time are confirmed per project.

Material & Performance

Custom PP round ducts are made from polypropylene, a lightweight thermoplastic synthetic resin with strong corrosion resistance, high-strength mechanical properties and good processing performance. The properties that matter in ventilation ductwork include:

• Acid and alkali resistance: PP withstands corrosion by high-concentration acids and alkalis across a wide pH range (pH 1-14) and a wide temperature range, preventing secondary chemical reactions between the medium and the pipe body.
• Smooth wall, low flow resistance: the smooth, uniform wall of the pipe and its fittings gives low flow resistance and resists scaling and deposit buildup.
• Sound insulation: PP has sound insulation performance that significantly reduces vibration and noise caused by air flow.
• Anti-condensation and low heat loss: PP is a poor thermal conductor, reducing condensation and heat loss along the run.
• Anti-freeze cracking: PP’s elasticity lets the pipe section expand with frost-heaving liquid without bursting.
• Light weight and easy installation: PP duct is light, easy to install and operate, and has excellent weldability – which also helps when custom sections must be handled and joined on site.
• Long service life: PP duct systems offer a service life of up to 50 years under specified operating conditions.

Flame retardant PPs is available where fire-rated ductwork is required; specify the required flame retardant grade when inquiring.

Applications

Custom PP round ducts are used wherever a tailored duct run is required for air movement and corrosive fume handling:

• Laboratory ventilation with non-standard duct layouts, where hood and bench positions fix the duct route.
• Workshop ventilation for corrosive gas treatment at normal temperature conditions.
• Chemical and plating process exhaust where dimensions follow the equipment layout and pipe runs.
• Warehouse ventilation and general air movement.
• Retrofit and replacement runs where existing duct sizes must be matched to extend or repair a system.

PP resists acid and alkali attack (pH 1-14), insulates sound, prevents condensation and stays light and easy to install – properties that apply equally to standard and custom sections.

Selection Notes & Quotation Information

To quote a custom PP round duct, provide: required diameter(s), wall thickness, section length and quantity, material grade (PP or flame retardant PPs), color, connection method (collar or flange), application, destination port, and your duct schedule or drawings. Gas composition, temperature and available static pressure help confirm wall thickness and reinforcement for the actual duty.

MOQ and lead time are confirmed per project. Request a quote via WhatsApp or email using the contact block below.

Installation & System Integration

Custom PP round ducts are connected with collar or flange joints:

• Collar connection: a collar at the section end receives the next section for a stable joint – fast field installation.
• Flange connection: flanges are welded to the duct and joined with screws – suited to high-sealing working conditions and allows maintenance disassembly.
• Hot-air welding: available where a continuous sealed run is preferred.

Large-diameter sections are reinforced with flange welding during production to prevent deformation. Complete systems combine custom ducts with matching accessories: PP 90° elbows, tees, reducers and flanges. See the full range of PP duct systems.

Related Products

• Polypropylene Round Ducts
• PP Air Duct
• PP Exhaust Duct
• Flame Retardant PP Duct
• PP 90° Duct Elbow
• PP Duct Flange
• Full PP Duct Range
• PP Air Duct Guide – a complete guide to PP duct types, sizes and materials.

FAQ

What is a custom PP round duct?

A custom PP round duct is a polypropylene ventilation pipe made to order: diameter, wall thickness, length, color and connection are confirmed per project instead of taken from a catalog. It is produced by PP sheet welding with flange reinforcement.

What can be customized?

Diameter, wall thickness, section length, material (standard PP or flame retardant PPs), color (beige or grey) and connection method (collar or flange).

What is the standard length?

Custom PP round ducts are supplied in 3 m sections or in lengths confirmed per project.

Is flame retardant PP available?

Yes. PPs flame retardant grade is available; specify the required flame retardant grade when inquiring.

How are custom ducts connected?

Two standard methods are offered: collar connection (a collar at the section end receives the next section) and flange connection (screwed flanges for high-sealing duties). Hot-air welding is available for continuous sealed runs.

How are custom orders confirmed?

Send your duct schedule and drawings with the inquiry. Each section is confirmed with approved dimensions, wall thickness and connection detail before manufacture. MOQ and lead time are confirmed per project.

Polypropylene round ducts are injection-molded PP ventilation pipes used to move air and low-concentration fumes in laboratories, workshops, warehouses and general exhaust systems. XICHENG supplies them as straight round duct sections from φ20 mm to φ500 mm in standard 3 m or 4 m lengths, with wall thickness matched to each diameter.

Polypropylene (PP) is a lightweight thermoplastic synthetic resin with high chemical resistance and good mechanical strength. Round PP ducts are injection molded to give a smooth internal surface, consistent wall thickness and low flow resistance. They are produced in standard and PPs flame retardant grades, in beige or grey, and support flange, socket or hot-air welding connections.

This round duct family is sold in two standard size groups: φ20-φ90 mm sections for ventilation and drainage duty, and φ110-φ500 mm sections for ventilation duty. Custom diameters, wall thicknesses and lengths are available. Duct sections are one part of a ventilation system: they connect to fans, fittings and dampers rather than replacing them, and the XICHENG range includes matching elbows, tees, reducers, flanges, couplings and airflow dampers so a complete PP duct line can be specified from one supplier.

Product Selection Summary

Good Fit

• Laboratory and process exhaust requiring corrosion-resistant rigid ductwork
• Workshop and warehouse ventilation at normal temperature conditions
• Chemical fume handling where smooth walls reduce pressure loss and deposits
• Systems built with flange, socket or hot-air welding joints

Conditions To Confirm

• Gas composition, concentration, temperature and moisture at the actual operating point
• Diameter, wall thickness and section length per duct run
• Connection method (flange, socket, or welding) for each joint
• Available static pressure and airflow schedule
• Flame retardant grade, when fire-rated ductwork is required

Not a Replacement For

• Fans, airflow balancing devices, room controls or treatment equipment

Technical Specifications

Confirmed Product Parameters

PPs pipe datasheet (PDF)

Available Sizes

Standard Size Options

Custom Sizes

Custom diameters, wall thicknesses and lengths are available for engineering projects. Send your duct schedule and drawings so each section can be confirmed with approved dimensions before manufacture.

Material & Performance

PP round duct pipes are corrosion resistant across a wide pH range (pH 1-14), which suits chemical fume and laboratory exhaust applications. The smooth inner wall of the pipe and its fittings gives low flow resistance and reduces scaling, keeping the duct system efficient over time.

Polypropylene offers several properties that matter in ventilation ductwork:

• Acid and alkali resistance: PP withstands high-concentration acids and alkalis in a wide temperature range, preventing secondary chemical reactions between the medium and the pipe body.
• Wear resistance and no scaling: the uniform, smooth inner surface lowers flow resistance and resists deposit buildup.
• Reduced vibration and noise: PP has sound insulation performance that dampens vibration and noise caused by air flow.
• Anti-freeze cracking: PP elasticity lets the pipe section expand with frost-heaving liquid without bursting.
• Anti-condensation, low heat loss: PP is a poor thermal conductor, reducing condensation and heat loss along the run.
• Light weight and easy installation: PP pipe is light, easy to install and operate, and has excellent weldability.
• Long service life: PP duct systems offer a service life of up to 50 years under specified operating conditions.

PPs flame retardant material is available where fire-rated ductwork is required; specify the required flame retardant grade when inquiring.

Applications

Polypropylene round ducts are used wherever ventilation is needed at normal temperature conditions, particularly where media are corrosive:

• Laboratory ventilation and fume exhaust ducting
• Workshop ventilation for corrosive gas treatment
• Warehouse ventilation and general air movement
• Chemical and plating process exhaust where pH resistance is required
• Daily-life and sanitary exhaust systems

Because PP prevents secondary reactions between the carried medium and the pipe body, it reduces the purification difficulty of industrial waste gas and waste liquid compared with metal ducting in corrosive services.

Selection Notes & Quotation Information

To size a polypropylene round duct system, provide the airflow schedule, duct layout, gas composition, concentration, temperature and available static pressure. Industry design practice specifies the required wall thickness and reinforcement under given wind speeds; for industrial exhaust systems with centrifugal fans at the end, reinforcement by external flanges is commonly used.

For a quotation please send: required diameter(s), quantity, section length and wall thickness, application, destination port, and preferred connection method. MOQ and lead time are confirmed per project.

Request a quote via WhatsApp or email using the contact block below.

Installation & System Integration

Round PP ducts are connected with flanges, socket joints or hot-air welding.

• Socket connection: a PP sleeve is welded at the end of each duct section so the next section inserts for a stable joint – fast field installation.
• Flange connection: PP flanges are welded at both ends and joined with screws – suited to high-strength, high-sealing working conditions and allows maintenance disassembly.
• Hot-air welding: creates a continuous sealed line where a monolithic run is preferred.

In industrial exhaust systems with a centrifugal fan at the end, the fan creates negative pressure inside the duct; reinforcement by external flanges is a common practice. For example, a 3-meter duct is typically reinforced with 2 flanges. Large square duct runs use external flange reinforcement plus internal PP circular pipe for structural support.

XICHENG supplies the matching range to complete the system: PP 90° elbows, flanges, couplings, tees, reducers and back draft dampers. See the full range of PP duct systems.

Related Products

• PP Air Duct
• PP Exhaust Duct
• Custom PP Round Duct
• Flame Retardant PP Duct
• PP Air Duct Guide – a complete guide to PP duct types, sizes and materials.

FAQ

What sizes are available?

Standard round duct sections run from φ20 mm to φ500 mm, in 4 m lengths for φ20-φ90 mm and 3 m lengths for φ110-φ500 mm. Custom diameters and wall thicknesses are available on request.

Can the duct be customized?

Yes. Custom diameter, wall thickness, length and color can be confirmed per project based on your duct schedule and drawings.

Is flame retardant PP available?

Yes. PPs flame retardant material is available; specify the required flame retardant grade when inquiring.

What is the working temperature range?

The working temperature is -15℃ to 80℃. Material grade affects the exact limits, so confirm your operating temperature with the order.

How are round duct sections connected?

Three methods are available: socket joints (a sleeve welded at the section end for fast insertion), flange connections (screw-locked PP flanges for high-sealing duties), and hot-air welding for continuous sealed runs.

What is the typical service life?

PP duct systems offer a service life of up to 50 years under specified operating conditions.

PP exhaust ducts, also known as plastic air ducts, are polypropylene ducts for exhausting corrosive gases from chemical plants, electroplating lines, laboratories and other facilities that produce acid and alkali fumes. They are made in standard and flame retardant PP grades, and can be produced as round, rectangular or oblate sections to suit the duct run.

PP is chosen for this duty because of its strong corrosion resistance and toughness. In toughness, PP air ducts are more prominent than PVC air ducts, so in terms of service life PVC ductwork cannot be compared. PP exhaust ducts are light in weight and resistant to acid and alkali attack, which keeps exhaust systems from corroding in aggressive industrial atmospheres.

An exhaust duct is one part of a fume extraction system: it connects to fans, fittings and airflow dampers rather than replacing them, and the XICHENG range includes matching elbows, tees, reducers, flanges and dampers so a complete PP exhaust line can be specified from one supplier.

Product Selection Summary

Good Fit

• Chemical plants, electroplating lines and laboratories producing acid or alkali corrosive gases
• Exhaust systems needing round, rectangular or oblate duct sections
• Duct runs from small injection-molded sections up to large sheet-welded diameters
• Projects where resistance to corrosive fumes and long service life matter more than first cost

Conditions To Confirm

• Gas composition, concentration, temperature and moisture at the actual operating point
• Duct shape (round, rectangular or oblate) and dimensions per run
• Diameter and length; material grade (standard or flame retardant)
• Connection method (flange, socket, or hot-air welding) for each joint
• Available static pressure and airflow schedule

Not a Replacement For

• Fans, gas treatment or scrubbing equipment, airflow balancing devices or room controls

Technical Specifications

Confirmed Product Parameters

Manufacturing & Quality Control

Two Production Methods

PP exhaust ducts are made by one of two methods, chosen by diameter:

• Injection molding: polypropylene raw material is extruded and molded by injection molding machine. The process is fully automated, giving uniform specifications and small dimensional error, and lengths can be customized. Injection molding is currently suitable for duct diameters below 600 mm.
• PP sheet bending and welding: for large-diameter plastic air ducts, a specific PP sheet is bent and welded for production. Plastic air ducts with a diameter greater than 500 mm are prone to deformation, so flanges are used to reinforce the PP duct body.

Quality Control

Production follows documented quality requirements:

• The specifications, types, properties and thickness of PP duct materials conform to the design drawings and the national industry product standards.
• Specifications and dimensions meet the design requirements; appearance must meet straight folding angles, uniform arcs, parallel end surfaces and no warped feet.
• The inner surface of the duct is smooth. Horizontal joints, reinforcing ribs inside the duct and convex-rib reinforcement are not used; longitudinal seams at the bottom are minimized – a rectangular duct with a bottom edge under 800 mm has no longitudinal seam on the bottom edge. Nuts, bolts, washers and rivets are matched to the pipe performance, using materials that do not cause electrochemical corrosion (or are galvanized).
• After fabrication, the duct is wipe-tested: the inner surface is checked with white silk cloth for oil stains and floating dust, then the openings are sealed with plastic film. Stacking yards are kept flat, with stacking layers determined by duct wall thickness and diameter to avoid deformation.
• Gaskets for duct connection flanges are closed-cell sponge rubber with a thickness of not less than 5 mm.

Applications

PP exhaust ducts are favored by facilities that generate acid and alkali corrosive gases:

• Chemical plants handling corrosive process fumes
• Electroplating lines with acid and alkali bath vapors
• Laboratories and fume hood exhaust systems
• Industrial exhaust systems for aggressive gas streams
• Corrosive fume ventilation where ductwork must resist attack over a long service life

Because PP resists corrosion and offers higher toughness than PVC, exhaust systems made from PP air ducts are built to last in these environments.

Selection Notes & Quotation Information

To size a PP exhaust duct system, provide the gas composition, concentration and temperature, the duct layout, required shape (round, rectangular or oblate), diameter and length, and the available static pressure. Confirm whether standard or flame retardant PP is required and the connection method for each joint.

For a quotation please send: duct shape and required diameter(s), quantity, section length and wall thickness, material grade (standard or flame retardant), application, destination port, and preferred connection method. MOQ and lead time are confirmed per project.

Request a quote via WhatsApp or email using the contact block below.

Installation & System Integration

PP exhaust ducts are connected with socket joints, flanges or hot-air welding.

• Socket connection: a PP sleeve is welded at the end of each duct section so the next section inserts for a stable joint – fast field installation.
• Flange connection: PP flanges are welded at both ends of each duct section and locked with screws – suited to high-strength, high-sealing working conditions and allows maintenance disassembly. Connection flange gaskets are closed-cell sponge rubber, not less than 5 mm thick.
• Hot-air welding: creates a continuous sealed line where a monolithic run is preferred.

Large-diameter PP ducts (above 500 mm) are prone to deformation and are reinforced with external flanges during production. Complete exhaust systems combine PP ducts with matching accessories: PP 90° elbows, tees, reducers and flanges. See the full range of PP duct systems.

Related Products

• Polypropylene Round Ducts
• PP Air Duct
• Flame Retardant PP Duct
• PP 90° Duct Elbow
• PP Duct Flange
• Full PP Duct Range
• PP Air Duct Guide – a complete guide to PP duct types, sizes and materials.

FAQ

What is a PP exhaust duct?

A PP exhaust duct, also called a plastic air duct, is a polypropylene duct for exhausting corrosive gases from chemical plants, electroplating lines, laboratories and similar facilities. It is made in standard or flame retardant PP, in round, rectangular or oblate sections.

What shapes are available?

Round, rectangular and oblate sections are available. Select the shape that matches your duct layout – the product options include round and rectangular.

What is the maximum duct size?

Injection-molded ducts are suitable for diameters below 600 mm. Larger diameters are produced by PP sheet bending and welding, and duct bodies above 500 mm are reinforced with flanges to prevent deformation.

Can the duct be customized?

Yes. Length is customizable on injection-molded ducts, and shape, dimensions, wall thickness and material grade are confirmed per project based on your duct schedule and drawings.

Is flame retardant PP available?

Yes. Flame retardant PP is available where fire-rated ductwork is required; specify the required flame retardant grade when inquiring.

How does PP compare with PVC for exhaust ducts?

PP has higher toughness than PVC, which is why PP exhaust duct systems offer a longer service life in corrosive fume duty. PP resists acid and alkali attack while staying light and easy to install.

PP air ducts, also known as PP ventilation ducts, are used to move corrosive gases and air in workshop exhaust, laboratory ventilation and industrial process systems. XICHENG makes them in two ways: injection molded from polypropylene, or formed from polypropylene sheets – in standard and flame retardant grades, in white, grey or natural.

PP air ducts are fully customizable in size, wall thickness, material (standard or flame retardant) and color, with competitive pricing for both small batch and bulk engineering orders. They offer strong ventilation capacity, stable acid and alkali resistance, corrosion resistance and temperature resistance. Because PP prevents secondary chemical reactions between the medium in the pipe and the pipe body, a PP duct run reduces the purification difficulty of industrial waste gas and waste liquid compared with metal ducting in corrosive service.

PP air ducts support direct flange connection for simple, fast installation, are light in weight and easy to install and replace, keeping overall project cost low. A PP air duct is one part of a corrosion-resistant duct system: it connects to fans, fittings and airflow dampers rather than replacing them, and the XICHENG range includes matching elbows, tees, reducers, flanges, couplings and air valves so a complete PP exhaust line can be specified from one supplier.

Product Selection Summary

Good Fit

• Workshop exhaust handling corrosive gases
• Laboratory ventilation and fume exhaust ducting
• Industrial exhaust and process fume systems at normal temperature conditions
• Projects needing fully customized duct size, wall thickness, material or color

Conditions To Confirm

• Gas composition, concentration, temperature and moisture at the actual operating point
• Required diameter, wall thickness and section length per duct run
• Material grade: standard or flame retardant (specify grade when fire-rated ductwork is required)
• Connection method (flange, socket, or hot-air welding) for each joint
• Available static pressure and airflow schedule
• Color and finish

Not a Replacement For

• Fans, airflow balancing devices, room controls or gas treatment equipment

Technical Specifications

Confirmed Product Parameters

Reference Sizes and Custom Dimensions

Reference Sizes

For reference, the XICHENG polypropylene round duct family covers standard sizes from φ20 mm to φ500 mm with wall thickness matched to each diameter, in 4 m sections for φ20-φ90 mm and 3 m sections for φ110-φ500 mm. See Polypropylene Round Ducts for the full standard size table.

Custom Dimensions

PP air ducts are made to order: diameter, wall thickness, section length and color are confirmed per project based on your duct schedule and drawings. Your custom dimensions can fall inside or outside the reference range – send the schedule and drawings so each section is confirmed with approved dimensions before manufacture.

Material & Performance

Polypropylene (PP) is a high-performance thermoplastic synthetic resin – a colorless, translucent, lightweight general-purpose plastic with excellent chemical resistance, heat resistance, electrical insulation, high-strength mechanical properties and good high wear-resistant processing performance. These properties are what make PP air ducts a practical choice for corrosive exhaust duty:

• No rust: PP withstands corrosion by high-concentration acids and alkalis across a wide pH range (pH 1-14) and a wide temperature range, preventing secondary chemical reactions between the medium and the pipe body.
• Wear resistance and no scaling: the uniform, smooth inner wall of the pipe and its fittings gives low flow resistance and resists deposit buildup.
• Reduced vibration and noise: PP has sound insulation performance that significantly reduces vibration and noise caused by air flow.
• Anti-freeze cracking: PP’s elasticity lets the pipe and fittings expand with frost-heaving liquid without bursting.
• Anti-condensation, low heat loss: PP is a poor thermal conductor, reducing condensation and heat loss along the run.
• Simple installation: PP pipe is light, easy to install and operate, and has excellent weldability.
• Long service life: a PP duct system offers a service life of up to 50 years under specified operating conditions.

Flame retardant PP is available where fire-rated ductwork is required; specify the required flame retardant grade when inquiring.

Applications

PP air ducts are widely used wherever corrosive gas handling is needed at normal temperature conditions:

• Workshop ventilation for corrosive gas treatment
• Laboratory ventilation and fume exhaust ducting
• Industrial exhaust systems and process fume extraction
• Chemical and plating process exhaust where pH resistance is required
• General air movement in plants that handle corrosive media

Because PP prevents secondary reactions between the carried medium and the pipe body, it reduces the purification difficulty of industrial waste gas and waste liquid compared with metal ducting in corrosive services. PP duct is light in weight, easy to install and replace, and keeps overall project cost low.

Selection Notes & Quotation Information

To size a PP air duct system, provide the airflow schedule, duct layout, gas composition, concentration, temperature and available static pressure. Confirm whether standard or flame retardant PP is required and the connection method for each joint, so the wall thickness and reinforcement are specified for the actual duty.

For a quotation please send: required diameter(s), quantity, section length and wall thickness, material grade (standard or flame retardant), application, destination port, and preferred connection method. MOQ and lead time are confirmed per project.

Request a quote via WhatsApp or email using the contact block below.

Installation & System Integration

PP air ducts are connected with socket joints, flanges or hot-air welding.

• Socket connection: a PP sleeve is welded at the end of each duct section so the next section inserts for a stable connection – fast field installation.
• Flange connection: PP flanges are welded at both ends of each duct section and locked with screws during installation – suited to high-strength, high-sealing working conditions and allows maintenance disassembly.
• Hot-air welding: creates a continuous sealed line where a monolithic run is preferred.

In industrial exhaust systems, centrifugal fans are usually installed at the end. They exhaust air and create negative pressure inside the duct; industry design specifications stipulate the required wall thickness and reinforcement method under specific wind speeds. PP air ducts are typically reinforced by external flanges – for example, a 3-meter duct is reinforced with 2 flanges. Large square air ducts are reinforced by external flanges, with internal PP circular pipes used for structural support.

A complete PP anti-corrosion pipeline system combines PP ducts with matching accessories: PP 90° elbows, tees, reducers, flanges, casings and back draft dampers – collectively the PP duct exhaust system. See the full range of PP duct systems.

Related Products

• Polypropylene Round Ducts
• PP Exhaust Duct
• Flame Retardant PP Duct
• PP 90° Duct Elbow
• PP Backdraft Damper
• Full PP Duct Range
• PP Air Duct Guide – a complete guide to PP duct types, sizes and materials.

FAQ

What is a PP air duct?

A PP air duct, also called a PP ventilation duct, is a polypropylene duct for moving air and corrosive gases in workshops, laboratories and industrial exhaust systems. It is injection molded from polypropylene or formed from PP sheets, in standard or flame retardant grades.

Can the duct be customized?

Yes. Diameter, wall thickness, material grade (standard or flame retardant) and color are fully customizable and confirmed per project based on your duct schedule and drawings.

Is flame retardant PP available?

Yes. Flame retardant PP is available where fire-rated ductwork is required; specify the required flame retardant grade when inquiring.

What is the working temperature range?

The working temperature is -15℃ to 80℃. Material grade affects the exact limits, so confirm your operating temperature with the order.

How are PP air ducts connected?

Three methods are available: socket joints (a sleeve welded at the section end for fast insertion), flange connections (screw-locked PP flanges for high-sealing duties), and hot-air welding for continuous sealed runs.

What is the typical service life?

A PP duct system offers a service life of up to 50 years under specified operating conditions.

Flame retardant PP duct sections are large-diameter ducts made from flame retardant polypropylene (PPs), used for industrial exhaust and waste gas handling. They are produced in the same PP sheet welding process as standard PP ducts and reinforced with a round PP flange, which gives the pipe body better compression resistance.

Standard PP and flame retardant PP are the two grades used across the XICHENG PP duct range. Flame retardant PP is selected where a duct run should limit the spread of flame in an industrial environment, such as waste gas treatment and ventilation equipment in plants that handle flammable or heat-generating processes.

A ventilation pipe is one part of a duct system: it connects to fans, fittings and airflow dampers rather than replacing them, and matching elbows, tees, reducers, flanges and dampers are available from the same supplier, so a complete PP duct line can be specified from one source.

Product Selection Summary

Good Fit

• Industrial exhaust systems where flame retardant duct material is preferred
• Large-diameter duct runs, including the 500 mm class, that benefit from flange reinforcement
• Waste gas treatment equipment and industrial ventilation installations
• Projects standardizing on flame retardant PP across a complete duct line

Conditions To Confirm

• Required diameter, wall thickness, section length and quantity
• Required flame retardant grade – specify the grade when fire-rated ductwork is required
• Gas composition, concentration, temperature and moisture at the actual operating point
• Connection method (socket or flange) for each joint
• Available static pressure and airflow schedule

Not a Replacement For

• Certified fire-rated or smoke-control ductwork – flame retardant PP reduces flame spread risk but is not a fire-rated system
• Fans, airflow balancing devices, room controls or gas treatment equipment

Technical Specifications

Confirmed Product Parameters

Diameters, wall thicknesses and section lengths are confirmed per project against your duct schedule and drawings.

Material & Performance

Flame Retardant PP

Flame retardant polypropylene (PPs) is a PP grade formulated to reduce flame spread compared with standard PP. It is produced in the same fabrication process as standard PP duct, so flame retardant sections can be specified for part or all of a duct run. V-0 flame retardant grade is available, and the required grade is confirmed per project against the actual duty and specification.

What Flame Retardant PP Does and Does Not Provide

V-0 is a material-level flame retardant grade: it describes how the PP material itself behaves in a vertical burning test, reducing the fire risk of the duct material in an industrial exhaust environment. It is not a substitute for certified fire-rated or smoke-control ductwork, which is a system-level fire-resistance rating. Where fire-rated or smoke-control ductwork is mandated by local code, confirm the required certification with the specification authority before selecting material.

PP Performance Properties

Flame retardant PP keeps the properties of polypropylene that matter in ventilation ductwork:

• Acid and alkali resistance: PP withstands corrosion by acids and alkalis across a wide pH range (pH 1-14), preventing secondary chemical reactions between the medium and the pipe body.
• Smooth wall, low flow resistance: the smooth, uniform wall of the pipe gives low flow resistance and resists scaling and deposit buildup.
• Sound insulation: PP has sound insulation performance that reduces vibration and noise caused by air flow.
• Light weight and easy installation: PP duct is light, easy to install and operate, and has good weldability.
• Long service life: PP duct systems offer a service life of up to 50 years under specified operating conditions.

Applications

Flame retardant PP ducts are used in industrial facilities where large-diameter ductwork handles exhaust air and waste gas, and where flame retardant material is preferred:

• Industrial waste gas treatment equipment, where large-diameter ducts connect process exhaust to treatment stages.
• Factory and workshop ventilation for corrosive gas handling, where flame retardant duct material is selected to limit fire risk.
• Chemical and plating process exhaust in plants with flammable or heat-generating processes.
• Duct runs requiring flange-reinforced large diameters for stable, compression-resistant sections.

Flame retardant PP resists acid and alkali attack (pH 1-14) and stays light and easy to install, while the round flange reinforcement supports the large-diameter sections this product is built for.

Selection Notes & Quotation Information

To quote a flame retardant PP duct, provide: required diameter(s), wall thickness, section length and quantity, the required flame retardant grade, application, destination port, and your duct schedule or drawings. Gas composition, temperature and available static pressure help confirm wall thickness and reinforcement for the actual duty.

MOQ and lead time are confirmed per project. Request a quote via WhatsApp or email using the contact block below.

Installation & System Integration

Flame retardant PP ducts are connected with socket or flange joints:

• Socket connection: a PP sleeve is welded at the end of each section so the next section inserts for a stable joint – fast field installation.
• Flange connection: PP flanges are welded to the duct and joined with screws – suited to high-sealing working conditions and allows maintenance disassembly.

Large-diameter sections are reinforced with round PP flanges during production to prevent deformation and improve compression resistance. Complete systems combine flame retardant ducts with matching accessories: PP 90° elbows, tees, reducers and flanges. See the full range of PP duct systems.

Related Products

• Polypropylene Round Ducts
• PP Air Duct
• PP Exhaust Duct
• Custom PP Round Duct
• PP 90° Duct Elbow
• PP Duct Flange
• Full PP Duct Range
• PP Air Duct Guide – a complete guide to PP duct types, sizes and materials.

FAQ

What is a flame retardant PP duct?

A flame retardant polypropylene (PP) ventilation pipe is a large-diameter duct made from flame retardant PP, used for industrial exhaust and waste gas handling. It is reinforced with a round PP flange for better compression resistance.

Is this a fire-rated duct?

No. Flame retardant PP reduces the fire risk of the duct material, but it is not a certified fire-rated or smoke-control duct and does not carry a fire-resistance rating. Where fire-rated ductwork is mandated, confirm the required certification with the specification authority.

What flame retardant grade is used?

V-0 flame retardant grade is available. Confirm the required grade for your project when inquiring, and the applicable grade is confirmed against the actual duty.

What sizes are available?

Flame retardant PP ducts are available in large diameters, including the 500 mm class. Diameter, wall thickness and section length are confirmed per project against your duct schedule and drawings.

How are the pipes reinforced?

Large-diameter sections are reinforced with round PP flanges, which improve the compression resistance of the duct body and prevent deformation.

Where are these pipes used?

They are used in industrial waste gas treatment equipment, factory and workshop ventilation, and chemical or plating process exhaust where flame retardant duct material is preferred.