Description

Product Overview

Custom PP round ducts 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

Parameter	Value
Product Type	Custom PP Round Duct
Material	PP (polypropylene) or PPs flame retardant grade
Size Range	Custom – diameter and wall thickness per project
Length	3 m or customized
Color	Beige / Grey
Connection Method	Collar / Flange
Fabrication	PP sheet welding; flange reinforcement for large diameters
Working Temperature	-15℃ to 80℃
Chemical Resistance	pH 1-14 (acid and alkali)
Certification	ISO9001, ISO14001, RoHS

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
• Polypropylene/PP Air Duct
• PP Plastic Exhaust Duct
• Flame Retardant PP Ventilation Pipe
• PP 90° Elbow
• PP Air 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.