Facing a pp duct vs pvc vs galvanized decision — and now PE in the running too — for an industrial process air system is usually a matter of matching your media, temperature, mechanical constraints, budget, and expected service life, not of declaring one material “the best.” This guide compares PP, PVC, galvanized steel, and PE across six engineering dimensions, then walks through a five-step selection order with a worked example.
Key Takeaways
- The selection order is media → temperature → mechanical/installation → lifecycle cost → certification/maintenance. The material is the solution to those variables, not the other way around.
- PP is the corrosion-workhorse thermoplastic for mid-temperature fume. Continuous service typically around 90°C (grade- and load-dependent), density 0.90–0.91 g/cm³, resistant to most acids, bases, and salts.
- PVC is stiffer and cheaper but capped at roughly 60°C. Standard PVC grades stop well below PP, and the material is more notch-sensitive in cold service.
- Galvanized steel gives stiffness and temperature range plastics cannot match — but wet acidic service attacks both the zinc and the steel.
- PE shares PP's polyolefin chemistry with a narrower temperature window. Typically 60–70°C continuous, softer, often lower first cost.
- Standard thermoplastics are combustible; flame-retardant grades change the picture. UL 94 runs from HB to V-0, and plastic duct pressure ratings assume low-pressure ventilation unless a grade is confirmed.
Direct Answer: Choose PP When…, PVC When…, Galvanized When…, PE When…
The decision is media + temperature + budget, not “plastic vs metal”
The most common mistake in duct material selection is collapsing four very different material families into one bucket called “plastic,” then comparing that bucket against metal. The result is a false equivalence: PVC, PP, and PE behave differently enough — in temperature, stiffness, chemical resistance, and joining method — that treating them as one option hides the actual trade-offs.
The variables that actually decide the material are your process media (what it is, at what concentration, at what temperature), the mechanical duty (duct diameter, span, positive or negative pressure), and the lifecycle cost picture in that specific service. This guide organizes those variables into a decision matrix (M3 below) and a five-step order (M4) so the pp duct vs pvc vs galvanized choice falls out of your conditions rather than a price list.
One-line rules per material
If you only remember one line per material, make it these:
– PP: choose it for corrosive aqueous service up to about 90°C continuous, where lightweight, weldable, homogeneous construction and broad acid/base/salt resistance matter — and don’t choose it where strong oxidizers or high service temperatures rule.
– PVC: choose it where you want more rigidity and lower first cost than PP at temperatures around 60°C or below, and can work with solvent-bonded joints — and don’t choose it where hot exhaust, low-temperature impact, or aggressive solvent service is in play.
– Galvanized steel: choose it for clean, dry, mechanically demanding runs — large spans, high negative pressure, or hot air well above plastic limits — and don’t choose it where wet acidic or persistently humid corrosive conditions attack the zinc and the steel.
– PE: choose it for low-temperature, budget-sensitive, flexible runs where PP is over-specified — and don’t choose it where temperature headroom or high mechanical duty decides.
How to use the five-step order
The full order is media chemistry → temperature → mechanical and installation constraints → lifecycle cost → certification and maintenance. Each step outputs a constraint that narrows the candidate list before the next step is considered.
Use the direct answer above as a fast first pass, then confirm with the matrix in the next section and walk the five steps once with your own numbers. The worked example in M7 shows the method end to end with real conditions.
How this guide is scoped
This comparison targets industrial and commercial process ductwork: chemical fume exhaust, laboratory ventilation, plating and pickling lines, and general corrosive-air handling. It does not cover residential HVAC systems, and it treats ducts, not pressure pipes — a duct is a low-pressure airflow pathway, which is a different duty class than a fluid pipe under positive pressure.
Deeper material-specific comparisons are covered by separate articles on this site: duct sizing and design, material selection for corrosive fumes, and what PP duct is. This page is the cross-material overview that sits above those, and it anchors into the overall PP air duct guide.
What Each Material Is Designed to Do
PP: the corrosion-workhorse thermoplastic
Polypropylene (PP) is a semi-crystalline thermoplastic whose working personality is defined by a broad chemical tolerance and a density of 0.90–0.91 g/cm³ — about one-eighth the density of steel, making the same duct run roughly 85–90% lighter by volume. That combination is exactly what an acid-fume system wants: the duct resists most aqueous acids, bases, and salts, and the light weight simplifies hanger and support layouts.
Industrial PP duct is typically extruded or fabricated and joined by hot-air welding and butt fusion, which produces homogeneous, essentially seam-free runs — there is no exposed coating or liner to delaminate. The temperature ceiling is the main limit: PP melts around 160–170°C and is commonly rated for continuous service around 90°C, always grade- and load-dependent. Above that, stiffness drops and the material softens. For the definitional background, see what PP duct is.
PVC: rigid, economical, temperature-capped
Polyvinyl chloride (PVC) is a mostly amorphous thermoplastic that trades some of PP’s chemical breadth for rigidity and economy. At a density of about 1.4 g/cm³ it is roughly 50% heavier than PP, which also means stiffer wall behavior at the same wall thickness for many sections. PVC duct is standard in many fume systems for this reason — it holds shape well and is inexpensive.
The defining limit is temperature: standard PVC duct is typically rated to about 60°C (140°F) continuous, below PP, and that rating covers both structural strength and corrosion performance. PVC is also more notch-sensitive than PP in cold service and is normally joined by solvent welding rather than hot-air fusion. Chlorinated PVC (CPVC) grades extend the temperature envelope to roughly 93°C (200°F) but are a separate family with their own joining requirements.
Galvanized steel: strength and cost, clean-service bias
Galvanized steel (GI) is carbon steel with a protective zinc coating (Wikipedia), at a density of about 7.85 g/cm³ and an elastic modulus on the order of 200 GPa — more than a hundred times stiffer than PP’s 1.3–1.8 GPa. That stiffness is what lets metal ductwork span long unsupported distances, handle high negative pressures, and carry large diameters that a thermoplastic section would need heavy bracing to match.
The trade-off lives in the chemistry. In clean, dry HVAC-style service, galvanized duct is durable and economical. But in wet acidic or persistently humid corrosive service, the zinc layer and then the steel substrate are attacked — the corrosion problem that a thermoplastic would have shrugged off becomes the reason the galvanized system fails and needs replacement.
PE: the softer polyolefin option
Polyethylene (PE) is a polyolefin like PP — chemically the same family — but its duct-grade behavior sits in a narrower, softer corner. Density runs about 0.94–0.96 g/cm³ and continuous service temperature typically about 60–70°C, below PP-H. Chemical resistance is broadly similar to PP (good against most acids, bases, and salts), but the temperature window is tighter and some hydrocarbon and chlorinated solvents cause swelling in PE.
PE duct appears where flexibility and first cost beat temperature range: budget-conscious, low-temperature runs, and in spiral-wound or butt-welded large sections where its toughness helps. For most corrosive fume services, PP is specified instead because its temperature headroom is meaningfully higher for a small price delta.
The takeaway for this section: PP is the general default for corrosive service, PVC the rigid economy option under 60°C, galvanized the mechanical-duty choice in clean air, and PE the low-temperature budget alternative — and each name should be attached to a specific grade before it is ordered.
Side-by-Side Matrix: Six Dimensions
This is the working table for the pp duct vs pvc vs galvanized (and PE) comparison: six dimensions that matter in duct selection, scored for each material from the verified values used throughout this guide. Read the row for the dimension your project cares most about, then read across to shortlist the materials that survive it.
| Dimension | PP | PVC | Galvanized steel | PE |
|---|---|---|---|---|
| Density (g/cm³) | 0.90–0.91 | ~1.4 | ~7.85 | 0.94–0.96 |
| Continuous service temperature | ~90°C (grade/load-dependent) | ~60°C (140°F) | far above plastic limits | ~60–70°C |
| Chemical resistance | most acids/bases/salts; not strong oxidizers | most acids/bases/salts; not strong oxidizers | wet acidic/humid corrosive service is the weak point | most acids/bases/salts; some solvents cause swelling |
| Stiffness (elastic modulus) | 1.3–1.8 GPa | higher than PP | ~200 GPa | lower than PP |
| Weight & installation | light, welded, expansion must be designed | heavier than PP, solvent-welded | heavy, flange/mechanical joints | light, tough, welded |
| Cost structure | mid first cost; corrosion-duty TCO wins | lower first cost; temperature-capped | low first cost in clean service; reversed in corrosive duty | often lowest first cost |
| Service life | long in its envelope (attributed reference: 50+ yrs) | good within 60°C envelope | clean service durable; corrosive service limited | good within its narrow envelope |
Chemical resistance by media class
For aqueous mineral acids, caustic solutions, and salt-bearing exhaust, PP, PVC, and PE all sit in the same working family: good resistance, with PP and PE generally the more forgiving pair. Galvanized steel is the odd one out — the same service that is routine for a thermoplastic is the condition that destroys zinc and then steel.
The boundary that all three thermoplastics share is strong oxidizing media — fuming sulfuric acid, high-concentration oxidizing acids such as chromic acid, and some organic solvents. In those services no standard thermoplastic is a default choice, and the selection moves to FRP or a confirmed specialty grade. Concentration and temperature interact with these limits, which is why a fabricator’s chemical resistance data sheet — not a general chart — is the working document.
Temperature: continuous service vs melting point
Temperature has two different numbers for a thermoplastic: the melting point and the continuous service ceiling. PP melts around 160–170°C (Wikipedia) but is rated for continuous service only to roughly 90°C; PVC to about 60°C; PE to about 60–70°C. The gap exists because polymers soften and creep well below their melting temperature under sustained load.
Galvanized steel operates far above all of these — that is its core advantage. But note the flip side: a metal duct that can tolerate hot gas does not tolerate the corrosive chemistry that may come with it. Temperature range and chemical resistance are separate columns, and the matrix keeps them separate for a reason.
Mechanical strength and pressure
Stiffness is where plastics and steel are in different universes: PP’s elastic modulus of 1.3–1.8 GPa against steel’s ~200 GPa is a difference of more than a hundredfold. Practically, that means metal ductwork carries large spans and high negative pressure with modest bracing, while long plastic runs need closer hanger spacing and expansion compensation.
Pressure class is also different in kind. Ventilation ductwork is a low-pressure system — the conventional design envelope for industrial low-pressure duct is on the order of 2 in. W.G. (about 500 Pa) positive or negative. Plastic duct systems do carry published negative-pressure ratings from manufacturers, sometimes tested to a 1.5:1 safety factor, but those ratings are grade- and design-specific. A duct is not a pressure pipe; if the duty exceeds the low-pressure ventilation envelope, the class must be confirmed against the material grade and design, or the system moves to metal or FRP. Sizing and layout decisions for the run are handled in the ventilation duct sizing guide.
Weight and installation
Weight drives installation cost. At 0.90–0.91 g/cm³, PP is light enough that long horizontal runs are manageable with routine supports; galvanized steel at 7.85 g/cm³ needs heavier structural support and more crew effort per meter. PE at 0.94–0.96 g/cm³ is similarly light to PP.
Joining method matters too. PP and PE are hot-air welded and butt-fused into homogeneous seams; PVC is typically solvent-welded; metal ductwork uses flanges, riveted or screwed seams, and sealants. Expansion is the hidden installation item: PP’s linear thermal expansion coefficient is on the order of 0.10–0.15 mm/m·°C — roughly 5–10 times steel’s ~0.012 mm/m·°C — so long plastic runs need expansion compensation that a metal designer may not have planned for.
Cost structure
The honest statement about cost is a direction, not a number. In clean service, galvanized duct typically has the lowest first cost because the material is cheap and metal fabrication is mature. PE is often low on first cost too, PP sits in the middle, and FRP is generally higher.
The direction reverses in corrosive service. One engineering reference indexes relative material costs for corrosive fume exhaust with galvanized steel at 1.0, polypropylene at roughly 1.5–3 times, and stainless steel and FRP higher still — yet that same reference and others describe plastic systems running for decades in corrosive service while galvanized steel fails and is replaced. Price per meter is not the decision variable; cost per year of reliable service in your specific media is.
Service life
Service life is a function of the envelope, not the material alone. In the service each material is designed for, all four can perform well over years: thermoplastic duct in its chemical and temperature envelope, galvanized steel in clean dry service.
Engineering references for corrosive fume exhaust estimate service lives on the order of 50+ years for polypropylene, 20–30 years for galvanized steel in that specific corrosive duty, and 30–50 years for stainless steel and FRP. These are attributed planning references, and real life varies with duty cycle, concentration, and operating discipline. Treat them as planning context, not a warranty — the working numbers come from the fabricator’s data for your grade.
Read the matrix as a shortlist generator, not a verdict: mark the rows that matter to your project, cross out the materials that fail them, and carry the survivors into the five-step order in the next section.
A Five-Step Decision Order
Step 1: Media chemistry
Write down what the duct actually carries: the chemical, its concentration, and whether it is aqueous or mixed with solids or organic vapor. Then eliminate. Galvanized steel drops out immediately in wet acidic or persistently humid corrosive service — the zinc and steel are attacked. Among the thermoplastics, PP and PE cover most aqueous acid/base/salt media; PVC covers the same class within its temperature cap; strong oxidizers and aggressive solvents eliminate all standard grades and point toward FRP or a confirmed specialty. A dedicated guide covers the duct materials for corrosive and acid fumes in depth when chemistry is the deciding variable.
Output of Step 1: a short list of materials whose chemistry tolerates your media. If the answer is “none of the standard four,” you have already found your FRP candidate.
Step 2: Temperature
Take the continuous service temperature of the gas stream, plus realistic peaks, and compare against the service ceilings: PP around 90°C, PVC around 60°C, PE around 60–70°C, all grade- and load-dependent. Any stream consistently above a material’s ceiling eliminates it — not at the melting point, but at the much lower continuous-service rating.
Output of Step 2: the temperature cap trims the chemical survivors. Above roughly 90°C continuous, no standard thermoplastic here is a default, and the candidate list shifts to metal or FRP with confirmed grades.
Step 3: Mechanical and installation constraints
Now impose the physical duty: duct diameter and run length, available support spacing, positive or negative pressure class, space for expansion compensation, and the joining method the installer can execute. Metal duct carries long spans and high negative pressure with light bracing; thermoplastic runs need closer supports and designed-in expansion for the same geometry.
Output of Step 3: a feasibility filter. If the run is long, high, and mechanically demanding with clean air, galvanized steel wins on stiffness alone. If it is corrosive but the supports and expansion are manageable, the thermoplastic candidates survive.
Step 4: Lifecycle cost
Compare first cost against total cost of ownership in your specific service. First cost favors metal in clean service and PE at the low end, but in corrosive duty the replacement cycle dominates: galvanized steel that fails in wet acidic service is the expensive option per year of service, while a thermoplastic that lasts decades in its envelope is the cheap one.
Output of Step 4: a primary candidate. In corrosive service the answer is usually PP within its temperature window, PVC where the temperature is comfortably below 60°C and rigidity matters, PE only for low-temperature budget runs, and galvanized steel only for clean mechanical duty.
Step 5: Certification and maintenance
Finally, check the fire-rating and pressure-class requirements of your installation. Standard PP, PVC, and PE are combustible; if the code or risk assessment demands a rated system, flame-retardant grades and their certifications must be confirmed with the supplier. Confirm pressure class per grade if the duty exceeds the low-pressure ventilation envelope, and plan the maintenance reality: welded thermoplastic seams and solvent joints, versus metal flanges and sealants, have different inspection and repair profiles.
Output of Step 5: you can name the material — grade, fire rating, and pressure class — and select the final duct specification on paper.
When FRP Is the Better Choice
What FRP is
Fiberglass reinforced plastic (FRP) is a composite of glass fiber and a resin matrix — the resin does the corrosion and temperature work, and the glass provides strength. Because the matrix varies (polyester, vinyl ester, phenolic, and others), FRP’s performance is decided by the resin, not by the word “FRP.”
The practical consequence: vinyl ester systems are commonly cited around 250°F (121°C), above PP, PVC, and PE — but that number belongs to the resin family, and the only reliable figure is the one on the fabricator’s data sheet for your specific resin and laminate.
When FRP beats the four
FRP earns its place in services that defeat the standard four. Hydrofluoric acid and some strong oxidizing media attack or disqualify standard thermoplastics; high-temperature corrosive gas sits above PP’s ~90°C ceiling; severe mechanical duty (impact, vibration, large unsupported spans) wants the strength-to-weight that a glass laminate provides. In those conditions, FRP is not an upgrade — it is the correct material.
For the middle of the matrix — aqueous acids and salts below 90°C with ordinary mechanical duty — the thermoplastics, especially PP, are usually the more straightforward and economical answer. FRP’s higher cost and different fabrication cycle only pay off when the service genuinely demands it.
What to ask an FRP fabricator
When FRP enters the picture, ask for three things in writing: the chemical resistance data sheet for the specific resin system proposed (not a generic chart), the laminate construction and its continuous service temperature for your media and concentration, and the fabrication and delivery timeline, which differs from thermoplastic duct.
Also ask about UV resistance and support spacing — FRP needs denser supports than the same run in steel, and outdoor service has its own degradation considerations. The point of the questions is that FRP performance is resin- and laminate-specific, so the answers define the material you actually get.
Why FRP is a specialist choice, not a default
FRP is a specialist option because it trades away the thermoplastics’ simplicity. It is heavier, the manufacturing process and lead time are different, and the performance is resin-dependent, so every order needs engineering confirmation rather than a catalog selection.
None of that makes FRP bad — in high-temperature, strongly oxidizing, or structurally demanding corrosive service it is the right call. But for the majority of acid-fume and lab-exhaust systems that sit inside the thermoplastic envelope, PP is the default and FRP is the specialist you escalate to when the envelope breaks.
Fire-Rated and Pressure Boundaries
Standard thermoplastics are combustible — flame-retardant grades change the picture
Standard-grade PP, PVC, and PE are combustible plastics, and that is the first fact of any fire discussion. Plastics are classified under UL 94 from HB (horizontal burn) through V-2, V-1, to V-0 — the highest conventional vertical-burn rating — and flame-retardant grades achieve those ratings through additives that modify combustion behavior.
A flame-retardant plastic is still a plastic, not a non-combustible material, and its rating is specific to the tested grade and thickness. If the project requires a rated system, the specification must name the standard, the grade, and the rating — and the same discipline applies whether the duct is PP, PVC, PE, or a composite.
| UL 94 class | What it means in the standard vertical burn test | Typical reading for duct |
|---|---|---|
| HB | Slow horizontal burn on a horizontal specimen | Standard-grade thermoplastic — combustible; generally accepted where no fire rating is demanded |
| V-2 | Vertical burn stops within 30 seconds; flaming drips allowed | Intermediate flame-retardant class; dripping behavior matters in plenum routing |
| V-1 | Vertical burn stops within 30 seconds; no flaming drip | Better flame-retardant surface behavior for duct |
| V-0 | Vertical burn stops within 10 seconds; no flaming drip | The most common target for flame-retardant duct grades — confirm the tested grade and thickness |
The rating you see on a datasheet belongs to a specific formulation, specimen thickness, and test method. Matching a duct to a fire classification means confirming the manufactured grade — not assuming a material family name carries the rating.
Pressure and vacuum: the ductwork low-pressure convention
Ductwork is a low-pressure system by design. The conventional envelope for industrial low-pressure duct is on the order of 2 in. W.G. (about 500 Pa), positive or negative, and plastic duct systems are engineered for that duty class — they are not pressure pipes.
Some manufacturers publish negative-pressure ratings for plastic duct systems, verified by testing with a defined safety factor (for example, 1.5:1). Those ratings exist and matter, but they are specific to the material grade, wall construction, and joint design. If your duty exceeds the low-pressure ventilation envelope, confirm the pressure class against the grade and design, or move to metal or FRP.
When these boundaries push you to metal or FRP
Fire rating and pressure are the two boundaries that can veto a thermoplastic candidate even when chemistry and temperature are fine. If the risk assessment demands a non-combustible or higher-rated system, or if the mechanical duty exceeds the low-pressure envelope, the selection moves up the list: metal for stiffness and temperature, FRP for corrosive duty with higher mechanical demands.
The decision rule is simple: stay inside a plastic’s envelope and it is the economical choice; touch the fire or pressure boundary and the upgrade is mandatory, not optional.
Worked Selection Example
The project
A plating line needs exhaust ductwork for hydrochloric acid pickling fumes: dilute HCl at roughly 60°C, drawn through a negative-pressure ventilation system, with a mid-range budget and a 40-meter run to the scrubber.
The buyer has seen galvanized steel quoted cheaper per meter and wants to check whether that holds up once chemistry and service life are in the picture — which is exactly the comparison this page exists to run.
Walking the five steps
Step 1 (media): dilute HCl is a wet acidic corrosive service — galvanized steel is eliminated immediately because the zinc and steel are attacked. PP, PVC, and PE all tolerate the chemistry. Step 2 (temperature): 60°C sits at the top of PVC’s envelope and below PP’s ~90°C ceiling, so both survive; PE’s 60–70°C ceiling is marginal at 60°C and gets trimmed. Step 3 (mechanical): a 40-meter run needs expansion compensation in plastic, and the negative-pressure class must be confirmed against the grade — both manageable for PP and PVC. Step 4 (cost): PVC has the lower first cost, but at 60°C the buyer is running at PVC’s limit; PP buys a margin at modest extra cost. Step 5 (certification): the fire rating and pressure class are confirmed with the supplier for the PP grade.
The example converges on PP for the 60°C dilute-acid service: full chemical compatibility, a comfortable temperature margin, and a manageable installation cost.
The result and how it changes with conditions
Change the conditions and the answer moves. Push the stream above about 90°C continuous, and PP drops out — the candidate becomes FRP or a confirmed higher-rated grade. Add hydrofluoric acid to the chemistry, and the standard thermoplastics fall away and FRP becomes the strong default. Switch the duty to a clean, dry, mechanically demanding run at high negative pressure, and galvanized steel — or stainless where chemistry demands it — takes over.
| If the duty changes to… | The five-step order moves to… |
|---|---|
| Sustained temperature above about 90°C | PP drops out — FRP or a confirmed higher-rated grade becomes the candidate |
| Hydrofluoric acid in the chemistry | Standard thermoplastics fall away — FRP becomes the strong default |
| Clean, dry, mechanically demanding run at high negative pressure | Galvanized steel takes over (stainless where chemistry demands it) |
| Duty that touches the fire-rating boundary | The upgrade is mandatory — a rated system, metal, or FRP, not optional |
The point of the example is not the answer, which is specific to the conditions, but the method: the five steps produce a defensible choice, and changing one input re-runs the order.
Common Selection Mistakes
Cost-first thinking ignores the corrosion penalty
Comparing first cost per meter without running the replacement math in your actual service is the most expensive shortcut in this domain. A galvanized steel duct that fails in wet acidic service gets replaced — often more than once — and the cheap first cost becomes the expensive total.
The matrix in this guide keeps cost as one row among six for exactly this reason: price is a comparison input, not the comparison. Run the five-step order with your media and temperature before the numbers are weighed against each other.
Treating all plastics as one material
PP, PVC, and PE are different materials with different temperature ceilings, stiffness, and joining methods. Specifying “plastic duct” and letting the fabricator choose is how a 60°C duty ends up on a PVC grade that is running at its limit.
Each material has its own envelope — PP to roughly 90°C, PVC to about 60°C, PE to 60–70°C — and the difference of 30°C between PP and PVC is the difference between a comfortable design and a marginal one. Name the material, name the grade, and check the data sheet.
Assuming “galvanized” means corrosion-proof
Galvanized steel resists atmospheric corrosion well, which trains people to treat it as universally corrosion-proof. In wet acidic or persistently humid corrosive service, the zinc layer and then the steel substrate are attacked — the galvanizing is consumed, and the duct fails.
The zinc coating buys time against atmospheric exposure, not against acid chemistry. If the media is corrosive, treat galvanized steel as eliminated at Step 1 of the decision order and move to a thermoplastic or FRP candidate.
Ignoring thermal expansion in long runs
Plastics expand roughly 5–10 times more than steel per degree. A long PP or PVC run without expansion compensation can buckle, rack the supports, or stress the joints in ways that show up as cracks and leaks a season later.
The fix is design-time: plan expansion loops or sliding supports into long plastic runs the way a metal system plans for its own movement. Thermal expansion is an installation-line item, not an afterthought.
Confusing flame-retardant with non-combustible
A V-0 flame-retardant grade is a meaningful safety upgrade over a standard combustible grade — and it is still a plastic. If the risk assessment or code requires non-combustible or a specific class, a flame-retardant thermoplastic may not satisfy it.
The discipline is the same as for temperature and pressure: confirm the rating against the requirement rather than assuming the label covers it. When the requirement is genuinely non-combustible, the boundary section of this guide points to metal or FRP as the upgrade path.
The common thread in all five mistakes is assuming a material’s reputation instead of checking its numbers. If this section tripped you on any of the five, that specific row in the matrix is the place to re-run your decision.
Sizes, Project Information & Next Step
Standard sizes: φ20–600 mm
XICHENG’s polypropylene PP air duct is produced in a standard outer-diameter range of φ20–600 mm, covering the sizes that most industrial fume and lab-exhaust runs call for.
Exact dimensions, wall options, and fittings are confirmed at quotation — size alone is a starting point, not a spec. The range is a reference for planning a run and for the RFQ list below, not a substitute for design confirmation.
What to send a duct supplier
To get a meaningful quotation and a confirmed material grade, send six items: the media and its concentration, the continuous (and peak) temperature, the air volume or duct diameter and run length, the positive or negative pressure class, the budget and expected service life, and any fire-rating or certification requirements.
| RFQ input | Why the supplier needs it |
|---|---|
| Media and concentration | Chemical compatibility drives the base material choice |
| Continuous and peak temperature | Confirms PP/PVC/PE stay inside their envelope — or pushes the selection up |
| Air volume, duct diameter, run length | Sizing, span, and stiffness — the mechanical dimension |
| Positive or negative pressure class | Confirms the pressure rating the grade must meet |
| Budget and expected service life | Positions first-cost versus lifecycle-cost trade-offs |
| Fire-rating or certification requirements | Names the standard, grade, and rating before quoting |
With those six inputs, a supplier can propose a material, a grade, and a price — without them, a quotation is a guess. The same list works for confirming an FRP fabricator’s resin and laminate choice in the M5 scenario.
Where to go next
If this page answered your pp duct vs pvc vs galvanized question, the deeper material guidance lives in the companion articles on this site: the PP air duct guide hub, what PP duct is, duct materials for corrosive fumes, and the ventilation duct sizing guide. Start with the hub for the cluster overview, then follow the branch that matches your immediate question.
For product specifications and availability, the polypropylene PP air duct page covers the φ20–600 mm range, with square-tubing and flame-retardant pipe options for adjacent needs. If this comparison resolved your material question, take your six RFQ inputs from the list above and confirm the grade with the supplier.
