Common Chemical Compatibility Chart for Fluid Handling | Apex Flow

Every leak, every premature failure, and every contaminated batch in a fluid system can usually be traced to one decision: a material that was not compatible with the fluid passing through it. This master compatibility chart brings the common metals, thermoplastics, and elastomers together in one place and rates them against the acids, bases, solvents, and oxidizers found across water treatment, chemical processing, and industrial fluid handling.

Apex Flow Solutions stocks valves, fittings, and tubing in each of these materials. Use this chart as your starting reference, then confirm temperature and concentration before specifying.

Building a full fluid path?

Every wetted component — valve body, seat, seal, fitting, and tubing — must be compatible, not just one. Contact our team with your chemistry and we will help you build a fully compatible system.

In This Guide

How to Use This Chart

Ratings use the standard four-tier scale at ambient temperature (~70°F) and typical concentration: A Excellent (continuous service), B Good (most service), C Fair (intermittent only), D Not Recommended. Higher temperature and concentration reduce every rating. Compatibility is not transitive across components — a compatible valve body with an incompatible seal still fails, so check every wetted material against the same fluid.

Full fluid path showing valve, fitting, and tubing that all must be chemically compatible

A fluid path is only as compatible as its weakest component. Body, seat, seal, fitting, and tube all contact the fluid.

Metals: Brass & 316 Stainless

Brass (C36000) is excellent for water, air, oil, and fuel gas but is attacked by ammonia, chlorides, and some acids through dezincification. 316 stainless steel handles a far broader chemical range and high temperatures, but it has one critical weakness shared across the series: chlorides and hypochlorite cause pitting and stress-corrosion cracking.

Chemical Brass 316 SS
Water (potable/process) A A
Compressed Air A A
Natural Gas / Propane A A
Diesel / Fuel Oil A A
Sodium Hydroxide (50%) C A
Sulfuric Acid (<50%) D C
Hydrochloric Acid (37%) D D
Sodium Hypochlorite D D
Ammonia (Aqueous) D A

Thermoplastics: PVC, CPVC, PP, PTFE

Thermoplastics excel exactly where the metals fail — chlorides, hypochlorite, and many acids — but each has solvent limits. PVC and CPVC are dissolved by ketones and aromatic solvents; CPVC adds higher temperature capability (to ~200°F vs PVC's ~140°F). PTFE is the universal performer.

Chemical PVC CPVC PP PTFE
Sulfuric Acid (<50%) A A B A
Hydrochloric Acid (37%) A A A A
Sodium Hydroxide (50%) A A A A
Sodium Hypochlorite A A B A
Acetone (Ketone) D D B A
Toluene (Aromatic) D D C A
Diesel / Fuel Oil B B B A
Hydrogen Peroxide (35%) B A B A

Elastomers: EPDM & FKM (Viton)

Seals fail more often than bodies. EPDM and FKM (Viton) cover opposite chemical territories, and choosing the wrong one is the most common cause of seal swelling and hardening.

Chemical EPDM FKM (Viton)
Water / Steam (hot) A C
Sodium Hydroxide (50%) A D
Sulfuric Acid (<50%) D A
Diesel / Fuel / Oil D A
Acetone (Ketone) A D
Sodium Hypochlorite C A
Large color-coded chemical compatibility matrix for fluid handling materials

The big picture: no single material clears every chemical. Metals fail on chlorides, PVC fails on solvents, and each elastomer covers half the map — which is why the fluid path is matched component by component.

Specifying the Whole Fluid Path

The practical takeaway is that compatibility is a system property. A common failure is a PVC ball valve (compatible with hypochlorite) fitted with an FKM seat — compatible — but installed with EPDM-sealed unions that are only "fair" with hypochlorite, which become the leak point. Build the full path from one consistent material logic: for chlorides and hypochlorite, use PVC/CPVC bodies with PTFE or FKM seals; for solvents and fuels, use PTFE and 316SS with FKM; for strong caustics, use PP/PTFE bodies with EPDM seals. When two chemistries conflict on one line, PTFE is the universal tiebreaker.

Standards & References

Material standards underpinning these ratings include ASTM A276 (stainless bar), ASTM B16 (free-cutting brass), ASTM D1784 (PVC/CPVC cell classification), ASTM D4101 (polypropylene), and ASTM D2000 (elastomer classification). For potable water contact, wetted materials should carry NSF/ANSI 61. Industry compatibility data is compiled in references such as the Cole-Parmer and manufacturer chemical resistance databases; treat any chart as guidance and validate against the specific manufacturer's data at your concentration and temperature.

Frequently Asked Questions

What material is compatible with the most chemicals?

PTFE (Teflon) is the most universally compatible material in fluid handling, resisting nearly all acids, bases, solvents, and oxidizers up to about 500°F. It is the default when a line sees conflicting chemistries.

Why can't I use stainless steel for chlorine or bleach?

Chlorides and sodium hypochlorite attack stainless steel through pitting and stress-corrosion cracking, even 316 grade. Use PVC, CPVC, or PTFE wetted parts for hypochlorite and chloride service.

Should I use EPDM or Viton seals?

EPDM is best for caustics, ketones, and hot water but fails with petroleum products. FKM (Viton) is best for acids, fuels, and oils but fails with strong caustics and ketones. Match the seal to your specific fluid.

Does one compatible component make the whole system compatible?

No. Compatibility is a system property — body, seat, seal, fitting, and tubing all contact the fluid. The least compatible component determines system life, so check every wetted material.

How does temperature change these ratings?

Higher temperatures lower compatibility. A material rated "A" at 70°F can drop to "C" at elevated temperature. Always verify ratings at your actual operating temperature and concentration.

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