PP Ducting

PP ductwork is a plastic pipeline made by extrusion molding of polypropylene (PP) resin. Its core value lies in utilizing the inherent excellent chemical resistance of PP material to address the issues of traditional metal ducts (such as galvanized iron, stainless steel) being prone to rust, perforation, and having a short lifespan in corrosive environments.

PP ducts can withstand corrosion from most acids, alkalis, and organic solvents (such asHydrochloric AcidSulfuric AcidNitric Acid、Sodium Hydride(Alcohol, etc.), with a lifespan significantly longer than metal pipes, especially suitable for environments such as chemical processing, electroplating, and laboratories. The density of PP material is much lower than that of metal, making PP ducts extremely lightweight. This facilitates easier transportation, handling, and installation, effectively reducing installation costs and labor intensity. Smooth interior wall, low friction resistance — The interior wall of PP pipes is extremely smooth, which resists dust adhesion and reduces fluid resistance. This means that under the same power of a fan, a greater air exhaust volume can be achieved, or a smaller fan power is required to achieve the same air volume, leading to greater energy savings.

PP material is easily connected by hot melt welding, offering high strength at the welds, excellent sealing, and nearly seamless joints. Specialized flanges can also be used for connection. In case of localized damage, repair and replacement are extremely convenient.

Section 3: Main Types

According to structure and application, PP ducts are mainly divided into:

PP Round Duct (Straight Pipe)

The most common form is the circular cross-section, with specifications ranging from several tens of millimeters to over a thousand millimeters. They offer excellent aerodynamic performance and are the most frequently used type.

PP Square Duct (Rectangular Duct)

When installation space height is limited, rectangular ducts are used to maximize space efficiency.

PP Reducer/Reducing Coupling

Used for connecting ventilation pipes of different diameters.

PP Elbow/Bend Pipe

Used to change the direction of ventilation pipes, commonly available in 90° and 45° elbows.

PP Tee/Four-way Tee

Fittings for ventilation ducts, including branches or collectors.

PP Air Valve: Used for adjusting the air volume in ventilation systems.

Four: Connection Methods

Hot Melt Welding (most commonly used):

Utilize a dedicated PP welding torch and welding rod to heat and melt the pipe and fittings, then connect them together. The bond is highly durable with excellent sealing, almost forming a single unit.

Flange Connection:

Welded PP flange at the pipe end, then secured together with bolts, with a sealing washer in between. Easy for disassembly and maintenance.

Socket and spigot joint

For small-diameter pipes, socket-and-spigot jointing (using PP-specific adhesive) can be employed.

In summary, the PP duct is the "expert" for solving the难题 of corrosive gas transmission. It excels in medium and low-temperature, highly corrosive conditions, and has become the standard ventilation pipeline material for industries such as chemicals and laboratories, thanks to its lightweight, corrosion-resistant, and energy-saving advantages. However, when selecting, it is crucial to pay close attention to its temperature resistance limit and outdoor aging resistance issues.