Huahao Sealing · Carbon Graphite Components
Huahao Sealing carbon graphite chemical resistance chart: 40+ common chemical media (acids/alkalis/salts/solvents/gases) across concentrations and temperatures, with A excellent / B good / C limited / X not recommended ratings for M106H/M120H/M191T/M254J grades. For chemical pumps, reactors, compressor seal selection.
Ratings are based on impregnated graphite immersion for 30 days at specified concentration and temperature, evaluating weight change, strength change, and appearance.
| Rating | Weight Change | Strength Retained | Appearance | Recommendation |
|---|---|---|---|---|
| A Excellent | < 1% | > 95% | No change | Long-term |
| B Good | 1-3% | 85-95% | Slight discoloration | Recommended |
| C Limited | 3-10% | 70-85% | Significant discoloration | After testing |
| X Not Recommended | > 10% | < 70% | Severe corrosion | Not recommended |
Test conditions: atmospheric pressure, 30% concentration (unless noted), 20°C. Ratings may decrease at higher temperatures.
| Media | Conc % | Temp °C | M106H Sb | M120H Resin | M191T Carb |
|---|---|---|---|---|---|
| Hydrochloric HCl | 30 | 20 | A | B | A |
| Sulfuric dilute | 10 | 20 | A | A | A |
| Sulfuric conc. | 98 | 20 | C | X | B |
| Nitric dilute | 10 | 20 | B | C | A |
| Nitric conc. | 60 | 20 | X | X | C |
| Phosphoric H3PO4 | 85 | 20 | A | A | A |
| Hydrofluoric HF | 10 | 20 | C | C | B |
| Acetic acid | 100 | 20 | A | A | A |
Carbon graphite body has good alkali resistance, but resin-impregnated grades may hydrolyze in hot concentrated alkali.
| Media | Conc % | Temp °C | M106H Sb | M120H Resin | M191T Carb |
|---|---|---|---|---|---|
| Sodium hydroxide | 30 | 20 | A | A | A |
| Sodium hydroxide | 50 | 80 | B | C | A |
| Potassium hydroxide | 30 | 20 | A | B | A |
| Ammonia water | 25 | 20 | A | A | A |
| Sodium carbonate | 20 | 20 | A | A | A |
| Ethanolamine MEA | 30 | 20 | A | B | A |
Salt solutions cause minor corrosion to carbon graphite, but chloride ions cause galvanic corrosion in metal-impregnated grades.
| Media | Conc % | Temp °C | M106H Sb | M254J Cu | M191T Carb |
|---|---|---|---|---|---|
| NaCl seawater | 3.5 | 20 | B | C | A |
| Calcium chloride | 30 | 20 | B | C | A |
| Sodium sulfate | 20 | 20 | A | A | A |
| Potassium nitrate | 20 | 20 | A | A | A |
| Sodium bicarbonate | 10 | 20 | A | A | A |
| Sodium hypochlorite | 5 | 20 | C | X | B |
Carbon graphite has excellent resistance to most organic solvents, making it the preferred seal material for petrochemical, pharmaceutical and fine chemical industries.
| Media | Conc % | Temp °C | M106H Sb | M120H Resin | M191T Carb |
|---|---|---|---|---|---|
| Benzene | 100 | 20 | A | A | A |
| Toluene | 100 | 20 | A | A | A |
| Acetone | 100 | 20 | A | B | A |
| Ethanol | 100 | 20 | A | A | A |
| Methanol | 100 | 20 | A | A | A |
| Gasoline | 100 | 20 | A | A | A |
| Crude oil | 100 | 80 | A | B | A |
A: long-term (10+ years). B: recommended (5-10 years) with periodic inspection. Both are production-ready; prefer A for critical service.
M191T carbonized at 1200°C+ completes graphitization with minimal impurities, near-pure graphite inertness. Resin impregnation in M120H degrades in strong oxidizing acids, so M191T is mandatory for concentrated nitric/sulfuric.
Reaction rate roughly doubles per 50°C increase. Room-temp A may drop to B at 80°C, C at 150°C. Consult high-temp data or engineers for high-temp service.
Submit your duty parameters (temperature, pressure, media, speed) — engineers reply with grade selection and quotation within 24 hours.
