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Why Material Selection Decides Pump Survival
In a chemical pump, the wetted material, meaning everything the liquid touches, is the component most directly exposed to attack. A correct material choice can give a pump decades of service; a wrong one can destroy it in hours.
This guide details every wetted material Youfu Lanke offers, the chemistry it withstands, and a compatibility matrix covering the media most commonly encountered in process plants.
Three forces act on the wetted material simultaneously: chemical corrosion (dissolution or reaction of the material), abrasive wear (mechanical removal by solids), and thermal stress (softening, creep, or ageing). No single material wins on all three; selection is always a trade-off.
The Fluoroplastic Family
Fluoroplastics are the most chemically inert engineering polymers available. Their carbon-fluorine bonds are among the strongest in organic chemistry, which is why lined pumps built from them can handle almost any acid, alkali, oxidiser, or solvent.
F46 / FEP (Fluorinated Ethylene Propylene)
Temperature: -30 to 150°C in pump service.
Resistance: resists virtually all acids, alkalis, strong oxidisers, organic solvents, and reducing agents at any concentration.
Used in: IHF, CQB, FZB, FSB, ZMD, GF (GDF), forming the core lining of the fluoroplastic range.
Why it dominates: melt-processable, so it can be rotomoulded into the complex passages of a centrifugal pump, producing a continuous, pinhole-free lining.
PTFE (Polytetrafluoroethylene)
Temperature: up to 180°C, the highest of the common fluoroplastics.
Resistance: the broadest chemical inertness of any polymer; attacked by essentially nothing in normal service except molten alkali metals and elemental fluorine at elevated temperature.
Used in: valve linings (ball, globe, check, plug, diaphragm), pipes and fittings, and high-temperature duties.
PTFE Trade-off
Not melt-processable in the same way as F46, so it is generally used where its moulded form (e.g. in valves) is practical.
PFA (Perfluoroalkoxy)
Temperature: high-temperature service comparable to PTFE.
Resistance: equivalent chemical inertness to PTFE.
Key advantage: melt-processable like FEP but tougher, with an exceptionally smooth surface and very low extractables, ideal for high-purity applications (semiconductor, pharma) and high-temperature duties where surface finish matters.
PVDF (Polyvinylidene Fluoride)
Temperature: to about 100°C in pump service.
Resistance: good general chemical resistance; notably good for certain halogenated solvents and bromine where it can outperform other fluoroplastics.
Used in: FSB as an economical alternative wetted material option, and in piping/fitting systems for compatible media.
Caution: narrower chemical scope than F46/PTFE/PFA, so verify each medium; strong amines and hot concentrated alkalis can attack it.
UHMWPE: Abrasion Meets Corrosion
Ultra-High Molecular Weight Polyethylene (UHMWPE) is the standout material when the medium is both corrosive and abrasive.
Its extremely long molecular chains give outstanding sliding abrasion resistance, far superior to any fluoroplastic, while still resisting many acids and alkalis.
Temperature: generally limited to ~80°C in continuous service.
Chemical scope: handles sulfuric acid up to 80%, nitric and hydrochloric acid up to 50%, plus acid/alkali/salt slurries.
Wear resistance
The 8–20 mm lining in the UHB-ZK is deliberately thick so it can be sacrificed gradually to solids wear while the steel housing retains pressure integrity.
Used in: UHB-ZK slurry pump, with open-type and closed-type impeller options to suit solids loading and size.
Rule of thumb: if the medium contains hard solids and is corrosive, fluoroplastic alone will be abraded through too quickly and stainless will corrode. UHMWPE is the only single material that addresses both.
Stainless Steel and Special Alloys
Where the medium is clean and only moderately corrosive, solid stainless steel offers toughness, high temperature capability, and easy precision machining, without any polymer lining.
304
General-purpose austenitic stainless; good for many organics, dilute non-chloride acids, water, and food-grade service.
316 / 316L
The addition of molybdenum improves pitting and crevice corrosion resistance; the standard choice for brines, organic acids, alcohols, oils, and many solvents.
316L (low carbon) gives superior weld corrosion resistance.
Duplex and special alloys
Where chloride content, temperature, or a specific chemical pushes 316L past its limit, duplex stainless (e.g. 2205) and higher alloys (e.g. Hastelloy-type grades) extend the envelope.
The chloride caveat
304 and even 316L are vulnerable to pitting and stress-corrosion cracking in the presence of chlorides, notably seawater and chloride brines.
For these, upgrade to duplex/special alloy, or move to a fluoroplastic-lined pump, which is immune to chloride attack.
Chemical Compatibility Matrix
Legend:
R = Recommended
C = Use with caution / verify conditions
N = Not recommended
| Medium | F46 / FEP | PTFE | PFA | PVDF | UHMWPE | SS 316L | Duplex / Alloy |
|---|---|---|---|---|---|---|---|
| Sulfuric acid, concentrated (98%) | R | R | R | C | R to 80% | N | C / grade-dependent |
| Hydrochloric acid (any conc.) | R | R | R | C | R to 50% | N | N |
| Nitric acid | R | R | R | C | R to 50% | C / dilute only | C |
| Hydrofluoric acid | R | R | R | C | N | N | N |
| Aqua regia | R | R | R | N | N | N | N |
| Caustic soda (NaOH) | R | R | R | C | R | R | R |
| Ferric chloride | R | R | R | C | R | N / pitting | N |
| Organic solvents (general) | R | R | R | R / halogenated OK | C / some swell | R | R |
| Sea water (chloride) | R | R | R | R | R | N / pitting | C / duplex grade |
| Abrasive slurries | N / erodes | R / best choice | C / soft solids only | - | - | - | - |
How to Read and Apply This Guide
Compatibility is a function of concentration, temperature, flow velocity, and aeration, not just the chemical name.
A material rated “R” for a dilute, cool acid may fail in a hot, concentrated version of the same acid. Treat the matrix above as a first-pass screen, then verify against the specific conditions of your duty.
Fluoroplastics (F46/PTFE/PFA) are the default whenever you see strong acids, alkalis, oxidisers, or mixed/unknown chemistries. PTFE/PFA extend the temperature ceiling.
PVDF earns its place for halogenated solvents and bromine where it can outperform other fluoroplastics, but verify its narrower scope.
UHMWPE is non-negotiable for abrasive slurries; nothing else here combines abrasion and corrosion resistance.
316L is excellent for clean, mild, chloride-free duties; but the moment chlorides or strong acids appear, move to fluoroplastic or duplex.
Whenever the matrix shows C, request confirmation for your exact concentration and temperature before finalising.
A material can be chemically perfect but still wrong if the pump’s construction cannot contain it: for example, a volatile toxic liquid needs a magnetic-drive (static seal) pump, not just a chemically compatible lining.
Pair this material guide with the Pump Selection Guide.
Maintenance
Once the right material and model are chosen, follow the Maintenance Guide to protect that investment: lining inspection and seal care extend the life of every material covered here.
© Youfu Lanke (优氟蓝科) · Corrosion-resistant chemical pumps · cnchemicalpump.com
Part of the Resources knowledge series: Knowledge Base · Selection Guide · Material Guide · Maintenance Guide · Troubleshooting
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YFTEL Pumps
Fluid Engineers & Technical Support, YFTEL Pump
YFTEL is a chemical pump manufacturer based in Hangzhou, China, with a 26,000 m² production base in Hangzhou, China, with a 26,000 m² production base in Anhui. Using the CAS-patented Fluoroplastic Alloy material, we produce 300+ models of corrosion-resistant pumps, valves and piping, exported to 30+ countries.
