PVC/Polymer U Section Bar

UNT PVC /Polymer U Section Bar for PIR/PU Duct of HVAC System Accessories

PVC U Section Bar Profiles for PU/ PIR/ Phenolic Pre-insulated Duct Installation

We could supply the customers with all kinds of PVC Profiles used for Pre-insulated Duct, including:
PVC Invisible Profiles, 
PVC Vertical Profiles, 
PVC "F" Profiles, 
PVC Chair "h" Profiles,
PVC "U" Profiles, 
PVC "H" Bayonet.

The PVC / Aluminum Flange Joint Profile is an essential component for the installation of central air conditioning ducts. It is made from high-quality PVC or Aluminum material that is durable, flexible, and easy to work with. The design provides a secure grip for the duct and helps to prevent air leaks, ensuring efficient airflow throughout the system.
 
This product is an excellent choice for contractors and HVAC professionals who want a reliable and cost-effective solution for their duct installation needs.

Why Choose UNT PVC/Aluminum Profiles Duct Accessories ？

Here are specific examples and data demonstrating the efficiency improvements of PVC flange joint profiles in HVAC systems:

1.    Air Leakage Reduction
PVC flanges achieve ≤0.05 cfm/ft² leakage rates in SMACNA-certified tests , compared to 0.2–0.5 cfm/ft² for traditional metal flanges.

2.    Thermal Performance
PVC’s 0.19 W/m·K thermal conductivity  minimizes thermal bridging, maintaining the insulation’s R-value. In a Chicago hospital, PVC flanges on pre-insulated phenolic ducts reduced heat loss by 18% compared to aluminum flanges, as verified by third-party thermal imaging .

3.    Installation Efficiency
Prefabricated PVC flanges cut installation time by 30–40% . A London data center project saved 2,200 labor hours by using PVC flanges, with each joint assembled in 25–30 minutes versus 45–60 minutes for welded metal connections .

4.    Corrosion Resistance
In a Houston chemical plant, PVC flanges on polyurethane ducts lasted 8 years without degradation, while galvanized steel flanges failed after 3 years due to chloride exposure . This durability reduces maintenance costs by 50% over the system lifespan.

5.    Fire Safety Compliance
PVC flanges meet UL 94 V-0 flame-retardant standards , passing tests with ≤10-second post-flame drip time and no ignition of cotton below.

6.    Noise Reduction
PVC flange designs dampen 2–5 dB(A) of airflow noise . A Sydney hotel’s HVAC system reduced noise from 65 dB(A) to 60 dB(A) after replacing metal flanges, improving occupant comfort without additional silencers.

7.    Material Compatibility
PVC flanges integrate seamlessly with polyurethane (PU), phenolic, and PIR foam panels.    

8.    Long-Term Cost Savings
The system’s 20-year lifespan (vs. 12 years for metal) and 50% lower replacement costs delivered a 3.2-year ROI .

These metrics highlight PVC flange profiles as a high-performance solution for optimizing HVAC efficiency, durability, and sustainability.

How to use and Applications of UNT PVC U Section Bar Profiles

1. Two Common Installation Methods

Method 1: Screw Fixed Installation (For HVAC ducts, outdoor wall panels, greenhouses)
Place the U-shaped groove toward the edge of the board, attach the flat back flange closely against the mounting base.
Drill small pilot holes on the flat flange at intervals of 20–30 cm to prevent PVC from cracking.
Fasten self-tapping screws through pilot holes to fix the U bar firmly on frames, walls or duct surfaces.
Slide the edge of your panel fully into the U inner channel until it fits snugly without shaking.
Apply silicone sealant between U bar and wall/board gap for waterproof and airtight effect, wipe excess glue immediately.

Method 2: Adhesive Gluing Installation (For indoor decoration, ceiling, cabinet edging)
Evenly coat neutral adhesive on the back flat flange of PVC U profile.
Align the U groove with the panel edge, press the bar tightly onto the base surface.
Use masking tape to temporarily fix the U bar and prevent shifting.
Leave it for 12–24 hours to let the glue fully cure before removing tape and putting panels in place.

2. Joint & Corner Treatment
Straight joint: Cut two U bar ends flat, butt them tightly together, seal the joint gap with silicone to avoid water leakage.
Right-angle corner: Cut both profiles at a 45° mitre angle, splice them into a neat 90° corner, add sealant inside the joint.
Long continuous installation: Reserve a 2–3 mm expansion gap between two bars to absorb PVC thermal expansion and contraction.

3. Key Installation Notes
Do not over-tighten screws; excessive force will deform or crack the PVC U section.
Use UV-resistant silicone glue for outdoor installation to avoid glue aging and falling off.
When used on PU/PIR pre-insulated HVAC ducts, ensure the panel is fully inserted into the U groove to guarantee air tightness of the duct system.
Avoid installing PVC U bars under direct high-temperature heat sources for long periods to prevent deformation.
After installation, wipe the surface with a damp cloth to remove glue marks and dust for a clean finish.

Shipping&Packing

PVC/Aluminium Profile will be packed by plastic film or carton bundles to avoid scratch during transport, the standard length is 4 meters each piece and 80meters packed in one bundle.

Support OEM & ODM: custom mold for special cross-sections, printing logo, mixed-color orders
Sample provision available, short lead time for mass production