PP Ducting

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

PP pipe can withstand corrosion from most acids, bases, and organic solvents (such asHydrochloric AcidSulfuric AcidNitric Acid、Sodium Hydride(Alcohol, etc.), with a lifespan far exceeding that of metal pipes, and is particularly suitable for environments such as chemical processing, electroplating, and laboratories. The density of PP material is significantly lower than that of metal, making PP ducts extremely lightweight. This results in easier transportation, handling, and installation processes, effectively reducing installation costs and labor intensity. Smooth interior wall, low friction resistance - The interior wall of PP pipes is extremely smooth, making it difficult for dust to adhere, resulting in low fluid resistance. This means that under the same power of the fan, a larger 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 via 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 very convenient.

III. Main Types

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

PP Round Duct (Straight Pipe)

The most common form is 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 commonly used type.

PP Square Duct (Rectangular Duct)

When installation space height is limited, rectangular ducts are used to more effectively utilize the space.

PP Reducer/Reducing Coupling

Used for connecting ventilation pipes of different diameters.

PP Elbow/Bend Pipe

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

PP Tee/Four-way Tee

Bends or junctions for ventilation ducts.

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

Four: Connection Method

Hot Melt Welding (most commonly used):

Utilize a dedicated PP welding torch and welding rod to heat and melt the pipe material and fittings together. The connection boasts high strength and excellent sealing, almost becoming a single unit.

Flange Connection:

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

Sleeve connection:

For small-diameter pipelines, socket-and-spigot jointing (using PP-specific adhesive) is applicable.

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