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 sheet, stainless steel) being prone to rust, perforation, and having a short lifespan in corrosive environments.

PP ducts can withstand corrosion from most acids, bases, and organic solvents (such asHydrochloric AcidSulfuric AcidNitric Acid、Sodium Hydroxide(Alcohol, etc.), with a lifespan significantly longer than metallic pipes, and is particularly suitable for environments such as chemical industries, electroplating, and laboratories. The density of PP material is much lower than that of metals, making PP ducts extremely lightweight. This facilitates easier transportation, handling, and installation, effectively reducing installation costs and labor intensity. Smooth inner wall, low friction resistance – The inner wall of PP pipes is extremely smooth, which prevents dust from adhering and reduces fluid resistance. This means that under the same power of the fan, a larger air 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 heat-fused 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.

III. Main Types

According to structure and usage, 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. It boasts excellent aerodynamic performance and is the most frequently used type.

PP Square Duct (Rectangular Duct)

When installation space height is limited, rectangular ducts are used to maximize space utilization more effectively.

PP Reducing Fitting / Reducer

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

Fork or manifold for ventilation ducts.

PP Air Valve: Used to adjust 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 material and fittings, then join them together. The connection boasts high strength and excellent sealing, nearly becoming a single entity.

Flange Connection:

Welded PP flange at the pipe end, secured together with bolts, with a gasket in between for ease of disassembly and maintenance.

Socket and Spigot Connection

For small-diameter pipes, socket-and-spigot joints can be used (PP-specific adhesive recommended).

In summary, PP ductwork 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 pipe material for industries such as chemicals and laboratories, thanks to its lightweight, corrosion-resistant, and energy-saving advantages. However, when selecting it, one must pay close attention to its temperature limits and outdoor aging resistance issues.

PP Duct