PP / PVDF
PP is the economical option, resistant to most acids and alkalis. PVDF offers broader resistance and high temperature performance.
Technical Guide
Material Compatibility
Guide
Chemical resistance guide for PP, PVDF, aluminum, SS316L body and PTFE, EPDM, NBR diaphragm.
Material Selection
Right Material =
Long Pump Life
Incompatible selection of pump casing and diaphragm material with the fluid causes swelling, cracking, corrosion and premature failure. The chemical structure, concentration and operating temperature of the fluid should be evaluated together when selecting the material.
The following is a general chemical compatibility summary for the four basic housing materials and three basic diaphragm materials. For specific fluids it is recommended to refer to the full compatibility table.
- PP (Polypropylene): acid, alkali, salt solution compatible; aromatic solvent incompatible
- PVDF: broad chemical resistance including strong acids, halogenated solvents
- Aluminum: neutral fluids; acid, alkali and brine incompatible
- SS316L: mild chemicals, food; HCl and chloride environment incompatible
- PTFE diaphragm: widest chemical resistance, -200°C to +260°C
Material Summary
Body and Diaphragm
Material Comparison
Alüminyum / SS316L
Aluminum for mechanical strength; suitable in neutral fluids. SS316L hygienic option for food and light chemicals.
PTFE Diyafram
Widest chemical compatibility. Preferred in strong acids, bases and solvents. Price is higher than others.
EPDM / NBR Diyafram
EPDM is compatible with hot water and steam, for food applications. NBR is suitable for hydrocarbon and oil transfer.
Material Questions
Material Selection
Questions
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For most acids PVDF is the safest choice. PP may be sufficient for low and medium concentration acids. For special acids such as hydrofluoric acid (HF) the specific chemical compatibility table should be consulted.
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For clean, neutral water (pH 6-8) the aluminum body is suitable. Salt water, acidic or alkaline water will damage aluminum. SS316L is recommended for salty environments.
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In non-chemical or mild chemical applications EPDM is the economical and adequate choice. In aggressive chemical, high temperature or ATEX applications the additional cost of PTFE is offset by long life and safety.