The Vajra Valve Material Index
The VMI ranks 11 valve materials by service versatility — how many process fluids each handles, and how well — on a transparent 0-100 score. One benchmark for "which material covers the most services."
Which valve material is the most versatile?
No single material is right for every service, but some cover far more of the process envelope than others. The Vajra Valve Material Index scores each material on how many fluids it handles at Excellent or Good, weighted by its overall compatibility rating. High-nickel alloys and reactive metals lead for chemical breadth; carbon and stainless steels lead on economics within their envelope. Use the index as a first cut, then confirm the specific fluid on its compatibility page.
VMI Methodology (open & reproducible)
Every input is a real material-fluid compatibility rating from our dataset — no estimated or fabricated values. For each material rated against at least 6 fluids:
- Versatility = fluids handled at Excellent or Good
- MeanScore = mean rating (Excellent 4 · Good 3 · Fair 2 · Poor 1 · Not Recommended 0)
- VMI = 60 × (Versatility / max) + 40 × (MeanScore / 4), scaled 0-100
Tiers: Universal (75+) · Broad (55-74) · Selective (35-54) · Specialist (<35). The weighting is Vajra's published methodology; the ratings underneath are real.
| # | Material | VMI | Tier | Service Versatility | Rated |
|---|---|---|---|---|---|
| 1 | SS 316L | 90 | Universal | 35 | 45 |
| 2 | Carbon Steel | 88 | Universal | 37 | 53 |
| 3 | PTFE | 59 | Broad | 13 | 13 |
| 4 | Hastelloy C-276 | 55 | Broad | 12 | 15 |
| 5 | PTFE seals | 53 | Selective | 8 | 8 |
| 6 | PTFE-lined | 49 | Selective | 8 | 9 |
| 7 | Titanium | 43 | Selective | 5 | 6 |
| 8 | Duplex 2205 | 40 | Selective | 7 | 11 |
| 9 | Bronze/Brass | 38 | Selective | 10 | 16 |
| 10 | Ductile Iron | 37 | Selective | 6 | 7 |
| 11 | PTFE seats | 34 | Specialist | 5 | 7 |
Versatility bar = fluids handled at Excellent/Good (of 37 max). "Rated" = fluids with data for that material. Versatility partly reflects dataset coverage; always confirm the specific fluid.
Connected Engineering
Selecting a valve material for a demanding service?
Send your fluid, concentration and temperature — our engineers translate the index into the right grade for your exact conditions, with full certification.
Built from the Compatibility Atlas. See also the Chloride Resistance Ranking and Temperature Envelope.