How to Select the Best Pump Materials for Your Application

Bobby Brown

Post 2025-05-29

How to Select the Best Pump Materials for Your Application

1. Why Choosing the Right Pump Material Matters?
2. Functions and Material Selection of Seats, Balls, and Diaphragms
3. Material Performance Overview
4. Common Combinations

1. Why Choosing the Right Pump Material Matters?

When selecting a pump, it’s essential to choose materials based on the type of fluid being handled. Using incompatible materials can lead to frequent clogging, corrosion, cracking, seal damage, and accelerated material degradation. These issues may cause production downtime and significantly increase maintenance costs. To prevent such problems, it’s critical to fully understand the fluid involved before purchasing a pump.
You should consider:
• Fluid properties – chemical composition, viscosity, specific gravity (density), and whether it contains particles or foam
• Operating conditions – flow rate, pressure, and temperature during transfer
• Regulatory requirements – whether the fluid is hazardous or requires food-grade or FDA-compliant materials

2. Functions and Material Selection of Seats, Balls, and Diaphragms

In selecting diaphragm pump components, fluid compatibility is important, but each part also has specific roles that affect material choices.
• Seat
The seat is the sealing surface where the ball rests, bearing repeated impact and fluid pressure to prevent backflow.
Due to frequent impacts, abrasion resistance is essential. For fluids with solids or high-cycle applications, choose wear-resistant materials like metal or acetal.
• Ball
The ball moves up and down with the fluid, affecting sealing and flow control.
Fluid density matters — for heavy liquids, use denser materials like stainless steel or PVDF to ensure proper sealing.
• Diaphragm
The diaphragm is the pump’s core moving part, flexing repeatedly to transfer fluid, and is often the most wear-prone.
Durability and cycle life are key. Choose materials based on fluid type, operating conditions, and any food or pharma compliance needs.

3. Material Performance Overview

Below is a reference of common seat, ball, and diaphragm materials used in GRACO’s Husky air-operated double diaphragm (AODD) pumps.
How to read this table:
1. Swipe left or right to view the full table.
2. Symbols: ✔ – Suitable, △ – Conditional/Depends, ✘ – Not recommended
Note: The following is based on data provided by Graco and is intended for initial reference only. For actual selection, please consult the manufacturer to confirm performance specs (e.g., temperature and pressure limits).

Material – Thermoplastics	Corrosive Fluids	High Viscosity / Density	Solids / Foam	Temperature	Med-High Pressure	High Duty Cycle	Hazardous Fluids	ATEX (Conductive)	Food Grade
PP (Polypropylene)	✔ – Resists common organics (check strong oxidizers)	✘ – ρ≈0.9; balls float, poor for heavy/viscous	△ – Avg. wear; avoid hard solids	✘ – 0–65 °C; soft hot, brittle cold	△ – OK mid-pressure; creeps at high	△ – Continuous duty, may deform over time	✔ – Inert to most hazardous fluids	✘ – Non-conductive; not ATEX	✔ – FDA grade available
PVDF (Kynar® Polyvinylidene Fluoride)	✔ – Excellent vs strong acids/alkalis & oxidizers	✔ – ρ≈1.78; heavy balls suit dense fluids	✔ – Wear-resistant for acid/alkali slurries	△ – −12 ~ 107 °C; avoid extremes long-term	✔ – High strength; handles high-pressure acids	△ – May micro-crack under repeated impact	✔ – Ideal for toxic/high-purity chems	✘ – Needs conductive grade or grounding	△ – FDA grades exist; costly
PTFE (Polytetrafluoroethylene)	✔ – Near-universal chemical resistance	✔ – ρ≈2.16; sinks in dense fluids	✘ – Poor abrasion; avoid sand	△ – Up to ~100 °C; stiff <4 °C	△ – OK moderate; short life high-pressure	✘ – Not for high-speed continuous use	✔ – Inert for aggressive/toxic fluids	△ – Conductive-filled PTFE available	✔ – FDA & USP VI
Acetal (POM, Delrin)	✘ – Solvent-resistant, not acids/alkali	✔ – Good with paint solvents; ρ≈1.3	✔ – Impact & wear resistant	✘ – −12 ~ 82 °C; brittle cold, soft hot	✔ – High modulus; seats resist creep	✔ – Long duty, fatigue-free	△ – OK for flammables; avoid strong acids	✔ – Conductive, antistatic	△ – Some FDA grades

Material – Rubber	Corrosive Fluids	High Viscosity / Density	Solids / Foam	Temperature	Med-High Pressure	High Duty Cycle	Hazardous Fluids	ATEX (Conductive)	Food Grade
FKM (Viton® Fluoroelastomer)	✔ – Aromatics, chlorinated solvents, acids, oils	✔ – ρ≈1.8; seals dense/thick fluids	△ – Hard; may abrade with slurry	✔ – −40 ~ 160 °C	✔ – Stable under high P/T	△ – Medium elastic life	✔ – Handles toxic/corrosive	△ – Conductive grades available	✘ – Rare in food
NBR (Buna-N Nitrile)	✘ – Oils & water only; poor in polar/oxidizing chems	✔ – ρ≈1.4; seals heavy oils	△ – Moderate wear	✘ – −10 ~ 80 °C; brittle cold	✔ – High tensile/tear strength	△ – Fair continuous life	✘ – Limited chemical scope	△ – Conductive formulas possible	△ – White FDA NBR exists
Neoprene (Chloroprene)	✘ – Alcohol/oils only; not ketones/oxidizers	✔ – ρ≈1.4; good in viscous/foam	✔ – Tough & abrasion-resistant	✘ – 0 ~ 80 °C; poor extremes	✔ – Strong under mid-pressure	✔ – Long elastic life	✘ – Low-risk fluids only	△ – Conductive black grade optional	△ – Food grade possible

Material – TPE	Corrosive Fluids	High Viscosity / Density	Solids / Foam	Temperature	Med-High Pressure	High Duty Cycle	Hazardous Fluids	ATEX (Conductive)	Food Grade
Hytrel (Thermoplastic Polyester Elastomer)	△ – Resists oils, mild chems; avoid strong acids/alkali	△ – ρ≈1.2; OK slightly heavy fluids	✔ – Tough & wear-proof	✘ – Max ~66 °C; ages hot	△ – Medium pressure capable	△ – Moderate life at high speed	△ – Check chemical compatibility	✘ – Non-conductive	✔ – FDA grades available
Santoprene (TPV)	△ – Handles some solvents/weak acids	✘ – ρ≈0.84; light ball may not seal in foam	✔ – Excellent abrasion resistance	△ – −40 ~ 82 °C	✔ – High strength; long life	✔ – Very long elastomer life	△ – OK for general hazards	✘ – Non-conductive	✔ – FDA grades available
Geolast (Graco TPV)	△ – For light oils/fuels; avoid strong solvents/acids	✘ – ρ≈1.0; floats in heavy fluids	✔ – Good wear for slurry	✘ – 10 ~ 82 °C; poor extremes	△ – Medium pressure only	△ – Average life (≈NBR)	✘ – Low-risk fluids only	✘ – Non-conductive	✘ – Not food grade

Material – Metals	Corrosive Fluids	High Viscosity / Density	Solids / Foam	Temperature	Med-High Pressure	High Duty Cycle	Hazardous Fluids	ATEX (Conductive)	Food Grade
Stainless Steel (SUS 316)	✔ – Wide chemical resistance	✔ – ρ≈7.9; best for heavy fluids	✔ – Hard, abrasion-proof	✔ – −40 ~ >300 °C	✔ – Preferred for high P	✔ – No fatigue	✔ – All hazardous fluids	✔ – Fully conductive	✔ – 316L sanitary compliant
Aluminum Alloy (Al)	✘ – Neutral fluids only	✔ – ρ≈2.7; heavy ball, light pump	✘ – Soft; low wear resistance	✔ – −70 ~ 200 °C	△ – ≤7 bar typical	✔ – Light, good heat dissipation	✘ – Reactive with acids/alkali	✔ – Conductive	✘ – Oxide contamination risk

4. Common Combinations

To help you quickly identify suitable selections, below are material combinations for "Seat – Ball – Diaphragm + Pump Body" commonly recommended by GRACO. These are for reference only — actual selection should consider your application, fluid characteristics, and production needs. For best results, consult with the manufacturer or an authorized distributor.
✦ Hytrel®-Acetal-Hytrel® + PP / Aluminum / Stainless Steel Body
Highly elastic, water- and oil-resistant, moderate wear resistance. Ideal for general-use fluids like water, lubricants, and windshield washer.
✦ Geolast®-Geolast®-Geolast® + Stainless Steel Body
High wear resistance for abrasive fluids, high volume, or particulate-laden liquids. Often used in automotive and industrial applications.
✦ Stainless Steel-Santoprene®-Santoprene® + Aluminum / Stainless Steel / PP Body
Durable and chemically compatible. Santoprene offers excellent fatigue resistance — suitable for chemicals, electronics, cleaning fluids, wastewater, etc.
✦ Acetal-PTFE-PTFE + Aluminum / Stainless Steel / Acetal Body
Excellent chemical resistance and low friction. Ideal for low-solids paints, pigments, and coatings.
✦ Stainless Steel-Stainless Steel-PTFE + Aluminum / Stainless Steel / Acetal Body
Suitable for high-viscosity, high-solids, and abrasive water-based fluids. High strength and corrosion resistance.
✦ PP-Hytrel®-Hytrel® + PP Body
For water and neutral fluids. Cost-effective with soft, flexible diaphragm. Not suitable for solvents.
✦ PP-PTFE-PTFE + PP Body
Affordable and highly chemical-resistant. Works well with acids, bases, cleaning solutions, and plating processes.
✦ Stainless Steel-Viton®-Viton® + Stainless Steel Body
Excellent for unleaded fuel and solvent handling (e.g., chrome plating baths). Great oil, solvent, and heat resistance.
✦ Kynar®-Viton®-Viton® + Kynar® Body
Designed for chromic acid and aggressive solutions. Viton® ball can be replaced with Kynar® if needed.
✦ Kynar®-PTFE-PTFE + Kynar® / Stainless Steel Body
Best choice for highly corrosive, hot, and acidic fluids. Common in semiconductor, chemical, and metal processing lines.