Body material decides whether a valve or pump survives its medium for ten years or fails in one season. This hub maps the material tiers PrimeFlow sources across valves, pumps, fittings and seals — brass through super-duplex, PVC through SS316L — to the service conditions that should drive the choice.
Indicative guidance — always confirm against the supplier datasheet and the actual medium chemistry before specifying.
| Material | Corrosion resistance | Pressure / temp envelope | Cost tier | Typical applications |
|---|---|---|---|---|
| Brass (CW617N) | Low–moderate; dezincification risk | PN16–25, −20..150°C | $ | Domestic water, HVAC balancing |
| Cast Iron | Low; no shock/severe corrosion | PN10–16, −10..120°C | $ | Non-potable water, large-bore butterfly/gate |
| Carbon Steel (WCB/A105) | Moderate; needs coating in wet service | Class 150–600, −29..425°C | $$ | Oil & gas isolation, steam, structural pressure parts |
| SS304 | Good; pits in chlorides | PN16–40, −20..200°C | $$ | Treated water, light chemical, food-adjacent |
| SS316 / 316L | Very good; Mo resists chloride pitting | PN16–40, −20..200°C | $$$ | Chemical process, marine splash, sanitary/hygienic |
| Duplex 2205 / Super-duplex 2507 | Excellent; high PREN for seawater | PN16–100, −50..250°C | $$$$ | Continuous seawater, offshore, high-chloride process |
| PVC / CPVC / PPR | Excellent vs acids/salts; UV & solvent limits | PN10–25, 0..95°C (PPR to ~95°C) | $ | Water distribution, HVAC branch pipe, chemical dosing |
Every material upgrade exists because the tier below it failed a specific way — not because higher-grade is "better" in the abstract.
Brass dezincifies in demineralised water, ammonia and high-chloride mains. SS304 removes the dezincification risk; SS316 adds chloride-pitting resistance for coastal or process water.
Dezincification risk → removedCast iron is brittle under shock loading and thermal cycling. Carbon steel (WCB/A105) adds weldability and tensile strength for pressure-rated isolation duty — at a cost and weight premium.
Brittle failure → ductileSS316 slows chloride pitting; it does not stop it under continuous seawater immersion. Duplex and super-duplex raise the PREN (pitting resistance equivalent number) for permanent high-chloride exposure.
Pitting under immersion → PREN upgradeNBR handles oils and fuels but degrades under ozone, UV and many solvents. FKM extends hydrocarbon and high-temperature compatibility; EPDM is the correct swap for water and dilute acid/base duty, not oils.
Elastomer / media mismatchPTFE cold-flows under sustained load and has a practical temperature ceiling near 180°C. PEEK holds dimensional stability at higher temperature and pressure — at a material cost premium.
Cold-flow / temp ceilingPVC and PPR resist acids and salts well but have UV, solvent and thermal-cycling limits that metal bodies do not share. The swap runs the other direction wherever chemical resistance outweighs mechanical duty.
Chemical resistance vs mechanical dutyThis is a starting point, not a final spec — always confirm against the SDS and the line sheet.
| Material / item | Common certificate | Why |
|---|---|---|
| Brass, SS304/316 (potable) | NSF/ANSI 61, WRAS | Drinking-water contact material safety |
| Carbon steel, duplex (oil & gas) | API 600 / 6D, NACE MR0175 | Pressure-retaining & sour-service qualification |
| SS316L (food/pharma) | FDA 21 CFR, 3-A, EHEDG, USP Class VI | Hygienic design & product-contact compliance |
| Bronze, super-duplex (marine) | DNV / ABS / LR type approval | Class society registration for marine service |
| All pressure-rated steel | EN 10204 3.1 / 3.2 | Material traceability per heat/lot |