Description

Product Overview

A PP duct tee is an injection-moulded polypropylene fitting with three openings that branches a ventilation run into two directions. It is the fitting used where a main duct distributes airflow to a branch line, or where two branch lines join back into a main run, and it matches the round PP duct range from φ20mm to φ500mm.

The tee is injection moulded in PP or flame retardant PPs, in beige or grey, and joins the duct run by hot air welding, with socket connection reinforcement at the joints. Being a moulded fitting, each size has consistent dimensions and wall thickness across batches. For the straight duct the tee connects to, see Polypropylene Round Ducts.

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

Product Selection Summary

Good Fit

• PP duct runs that need to branch a main line into one or more branch lines
• Distribution systems feeding multiple exhaust points, hoods or workstations
• Corrosive exhaust and ventilation systems using the round PP duct range
• Projects needing flame retardant fittings for part or all of a run

Conditions To Confirm

• Duct diameter (φ20mm to φ500mm, 17 standard sizes) and quantity
• Material grade: PP or flame retardant PPs
• Branch position and the number of branch points in the run
• Gas composition, concentration, temperature and moisture at the operating point

Not a Replacement For

• Fans, airflow balancing devices, dampers or gas treatment equipment

Technical Specifications

Confirmed Product Parameters

Parameter	Value
Product Type	PP Air Duct Tee (polypropylene duct tee)
Material	PP (polypropylene) or PPs flame retardant grade
Size Range	φ20-500mm – 17 standard sizes
Connection	Hot air weld; socket connection reinforcement
Fabrication	Injection molding
Color	Beige / Grey
Working Temperature	-15℃ to 80℃
Chemical Resistance	pH 1-14 (acid and alkali)
Certification	ISO9001, ISO14001, RoHS

Available Sizes (φ)

Diameter	Diameter
φ20mm	φ160mm
φ25mm	φ200mm
φ32mm	φ250mm
φ40mm	φ315mm
φ50mm	φ355mm
φ63mm	φ400mm
φ75mm	φ450mm
φ90mm	φ500mm
φ110mm

Material & Performance

Because round fittings are injection moulded rather than welded from sheet, the tee keeps the same corrosion resistance as the welded duct while offering consistent moulded dimensions, smooth internal surfaces and a shorter production time for standard sizes.

PP duct tees are injection moulded from polypropylene, chosen for corrosive fume handling in ductwork:

• Acid and alkali resistance: PP withstands corrosion by high-concentration acids and alkalis across a wide pH range (pH 1-14).
• Sound insulation: PP reduces vibration and noise caused by air flow through the branch point.
• Light weight: moulded PP fittings are light and easy to handle and weld on site.
• Consistent moulded dimensions: each size is produced to a standard mould, giving uniform dimensions and wall thickness across batches.
• Long service life: PP duct systems offer a service life of up to 50 years under specified operating conditions.
• Anti-condensation: PP conducts heat poorly, reducing condensation and heat loss at the fitting.

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

Applications

Main and Branch Duct Structure

In a ventilation system, the tee is the connection point where ducting splits: a main duct carries the airflow along the run, and at each tee a branch duct leads off to an exhaust point, hood, bench or workstation. The same fitting also works in reverse, joining branch lines back into the main return run.

• Distribution runs – one main line feeding several branch lines
• Multi-point exhaust – fume hoods, benches and cabinets connected along one main duct
• Collection runs – branch lines merging into a main line to the fan or scrubber
• Exhaust and ventilation systems – the same fitting serves laboratory, workshop and chemical exhaust runs built from round PP duct

A typical branch layout runs the main duct along the length of the room or building, with a tee at each distribution point and a short branch duct leading to the exhaust point. This lets one main line serve several hoods or benches from a single fan and control setup, which is why tees are among the most common fittings in a multi-point PP duct system. Each branch can be fitted with its own damper or valve where individual airflow control is needed at the exhaust point.

Selection Notes & Quotation Information

Equal-Size Tees and Diameter Changes

The standard tee has three equal openings of the same diameter, matching the duct size at the branch point. Where the branch line uses a smaller diameter than the main line, add a concentric reducer at the branch opening so both sides weld to matching diameters.

To Quote PP Duct Tee

Provide: duct diameter (φ20-500mm), quantity, material grade (PP or flame retardant PPs), color (beige or grey), application, destination port, and your duct schedule or drawings.

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

Installation & System Integration

PP duct tees are joined to the duct run by hot air welding, and each joint is reinforced with a socket connection. The same joining method applies to straight duct, elbows and reducers, so the whole main and branch structure can be welded and sealed as one continuous system, with no mechanical clamps required along the welded joints.

Where a run will be disassembled later for maintenance, flange connections are used at those points instead, so the tee can be bolted between flanged sections.

Complete systems combine tees with straight duct, elbows and flanges. See the full range of PP duct systems.

Related Products

• Polypropylene Round Ducts
• PP 90° Elbow
• PP 45° Elbow
• PP Concentric Reducer
• 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 PP duct tee?

It is an injection-moulded polypropylene fitting with three openings that branches a round PP duct run into two directions, connecting main and branch duct at the distribution point.

What sizes are available?

17 standard sizes from φ20mm to φ500mm: φ20, φ25, φ32, φ40, φ50, φ63, φ75, φ90, φ110, φ160, φ200, φ250, φ315, φ355, φ400, φ450 and φ500mm.

Can the branch be a different size from the main duct?

The standard tee has three equal openings. For a smaller branch, add a concentric reducer at the branch opening so both sides weld to matching diameters.

How is it connected?

By hot air welding to the duct run, with socket connection reinforcement at each joint – the same method used for straight duct and other round fittings.

Is flame retardant PP available?

Yes. The tee is available in standard PP or flame retardant PPs; specify the required flame retardant grade when inquiring.

What do I need to provide for a quote?

Duct diameter, quantity, material grade, color, application, destination port, and your duct schedule or drawings.