Duct & Stacks
Round and rectangular runs, roof stacks with guy points and rain caps.
PP Ducting, Hoods & Fittings for Corrosive Exhaust
Galvanized duct rots from the inside in acid service; PP duct simply doesn't. JHF prefabricates complete polypropylene duct networks — straight lengths, elbows, tees, reducers, dampers, capture hoods and stack sections — from your layout drawing, labels every piece to the plan, and nests the lot into containers so site work is bolting, not fabricating.
We also supply PP pipes, fittings and PPH valves for pumped chemical lines, so the whole corrosive circuit comes from one factory.
- Round duct DN110 – DN2000; rectangular to your dimensions
- Wall 4–15 mm, spiral-reinforced or ribbed for vacuum service
- Flanged, socket or butt-weld joints; EPDM/FKM gaskets included
- Dampers, non-return flaps, flexible connectors, rain caps, sampling ports
- PP/PPH pipes, socket & butt-weld fittings, ball and butterfly valves
Technical data
Typical Specification
| Round duct | DN110 – DN2000, wall 4–15 mm; spiral-wound or sheet-rolled with welded seam |
| Rectangular duct | Any section to ~2,000 × 2,000 mm, ribbed for flat-wall stiffness |
| Fittings | Elbows (segmented/smooth), tees, Y-branches, reducers, end caps, inspection ports, condensate drains |
| Airflow control | Manual and actuated butterfly dampers, multi-blade balancing dampers, non-return flaps |
| Capture | Slot hoods for tank lips, canopy hoods, push-pull systems, lateral extraction rails, enclosure panels |
| Joints | Flanged (drilled to DIN/ANSI or your pattern), socket weld, butt weld; gaskets and bolt sets included |
| Pressure rating | Designed per system: −3,000 Pa vacuum to +2,000 Pa positive typical; reinforcement per calculation |
| Pipes & valves | PP-H/PPH pressure pipe and fittings (socket & butt-weld), ball valves, butterfly valves, diaphragm valves for dosing lines |
| Prefabrication | Cut-to-plan with piece labels matching the isometric; assembly drawing supplied; nested packing to minimize freight volume |
Range
Everything Between Hood and Stack
Pipe & Fittings
Socket and butt-weld systems for pumped acid, dosing and rinse lines.
Valves
PPH ball, butterfly and diaphragm valves with EPDM/FKM seals.
Dampers & Hoods
Balancing dampers, slot and canopy hoods shaped to your tanks.
Why prefabricated
Site Welding Is the Expensive Part — So We Remove It
- From your layout to an isometric. Send a floor plan or even a sketch with dimensions; we return a numbered isometric, and every shipped piece carries its number.
- Balancing designed in. Branch dampers and duct sizing are calculated so far tanks actually get suction — the most common failure of locally cobbled systems.
- Freight optimized. Straight lengths nest, fittings pack inside duct, gaskets and bolts bag per joint. Customers regularly fit a whole workshop's network in one container.
- Compatible with anything. Flange patterns drilled to mate your existing scrubber, fan or duct — metric or imperial.
Combine with a PP scrubber and matched fan for a complete corrosion-proof exhaust line, or see turnkey systems.
FAQ
Ducting Questions
Can my own team install it?
Yes — flanged systems bolt together with the assembly drawing and piece labels; no plastic welding skills needed on site. Weld-joint systems need a plastic welder, which we can guide by video call.
How do you keep freight cost sensible for bulky duct?
Nesting: smaller diameters ship inside larger ones, fittings travel inside straight lengths, and we quote the real loading plan with the price so there are no surprises.
Is PP duct fire-safe?
Standard PP is combustible; for fire-sensitive plants we offer flame-retardant PP (V-0/V-2 grades) and can integrate fire dampers at compartment boundaries per your code.
Can you match existing flange patterns?
Send a rubbing or dimensions of one flange — we drill all mating pieces to match, DIN, ANSI or non-standard.
Get it priced
Send a Layout — Get an Isometric and a Container Plan
A dimensioned sketch or DWG is enough. You receive the isometric, piece list, loading plan and factory price — typically within one working day.
WhatsApp +86 186 1558 6932 · sales@jhf2017.com
Numbered piece labelsGaskets & bolts includedNested container packing