PVDF vs PP dosing pump — which material for which chemical
Short answer: A standard PP pump is adequate for antiscalant, SMBS, alkali and sodium hypochlorite — and it is far cheaper. PVDF is only necessary for aggressive chemicals such as 98 percent sulphuric acid or HCl. PVDF costs roughly double, so buying it unnecessarily wastes money — but not buying it when it is needed costs far more.
What "material" actually refers to
The parts of a dosing pump that contact the chemical — the pump head, diaphragm, valves and suction/discharge tubing — are called the wetted parts. The material specification refers to these, not to the whole pump.
- PP (Polypropylene): standard plastic, suitable for most chemicals, economical
- PVDF: a tougher plastic that withstands strong acids and solvents
- PTFE (Teflon): the most resistant, offered on the motorised MAX series
Chemical compatibility chart
| Chemical | Where it is used | Material |
|---|---|---|
| RO antiscalant | RO feed line | PP is adequate |
| SMBS (dechlorination) | RO feed line | PP is adequate |
| Sodium hypochlorite | Disinfection | PP works, PVDF lasts longer |
| Caustic soda (NaOH) | Raising pH | PP is adequate |
| Sulphuric acid 98% | Lowering pH | PVDF essential |
| Hydrochloric acid | CIP, pH control | PVDF essential |
| Boiler oxygen scavenger | Boiler feed | PP is adequate |
| Cooling tower biocide | Cooling water | PP to PVDF depending on type |
| Polymer / coagulant | ETP | PP is adequate |
Price difference
| Model | PP (standard) | PVDF |
|---|---|---|
| NEO 6 LPH | ₹6,090 | ₹14,700 |
| NEO 10 LPH | ₹7,035 | ₹15,750 |
| NEO PRO 6 LPH | ₹14,700 | ₹23,100 |
| MAX 25 LPH | ₹25,725 | ₹42,000 (PTFE) |
| MAX 40 LPH | ₹28,350 | ₹44,625 (PTFE) |
What happens with the wrong material
This is what we have seen repeatedly when a PP pump is used on acid:
- Two to four weeks: the diaphragm begins to swell and dosing falls off
- One to two months: valve seats fail and chemical starts to weep
- Two to three months: the pump head cracks and acid escapes — which is dangerous
The level switch has a material too
This is frequently overlooked. A standard level switch cannot be used with a PVDF pump — it needs a Teflon wire version:
- Standard level switch — ₹1,050, for PP pumps
- Teflon wire level switch — ₹1,312, for PVDF pumps
The decision in one line
- RO plant, antiscalant or SMBS: PP — the NEO 10 LPH is the usual choice
- Chlorine dosing: PP works, but PVDF will last longer
- Acid dosing (pH correction): PVDF, no compromise
- ETP/STP at higher flows: PTFE versions of the MAX series
- Unsure which chemical: send us the name and we will confirm
Confirm the right material for your chemical
Just send the chemical name and concentration — we will confirm whether PP is adequate or PVDF is required.
💬 WhatsApp par poochhein 📞 9910646957Frequently asked questions
What is the difference between PP and PVDF dosing pumps?
The difference lies in the wetted parts, meaning those components that contact the chemical. PP is a standard plastic suitable for most chemicals, while PVDF is a tougher plastic that withstands strong acids and solvents, but costs roughly twice as much.
Is PVDF needed for antiscalant?
No. A standard PP pump is perfectly suitable for antiscalant and that is what most RO plants use. PVDF is only necessary for aggressive chemicals such as ninety eight percent sulphuric acid or hydrochloric acid.
What happens if a standard pump is used on acid?
Within a few weeks the diaphragm swells and dosing drops off, then the valves fail, and within two to three months the pump head can crack and acid begins to escape. That is a genuine safety hazard, not just a pump failure.
What is the difference between PTFE and PVDF?
PTFE, or Teflon, is even more chemically resistant. It is generally offered on the motorised MAX series which handle heavy continuous duty, while smaller solenoid pumps are offered in a PVDF option.
Does a PVDF pump need a different level switch?
Yes. A PVDF pump should be fitted with a Teflon wire level switch, because a standard wire will not survive the chemical. It is supplied separately, so please mention it when ordering.