Impervious Graphite PH (Pre-hardened)
Heat-treated state · default condition
GB GB/T 12762
Standard choice for hydrochloric/sulfuric/phosphoric acid heat exchangers and columns up to about 170 °C.
Values for the PH condition
Other Impervious Graphite tempers and conditions
Impervious Graphite is listed in 3 conditions; see the grade overview at Impervious Graphite.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
PTFE / fluoropolymer impregnated graphite | Use for very aggressive or high-purity duty (HF, mixed halide acids, pharma) where resin extractables are unacceptable. | — | 20 | 0.4 | 20 HV | 100 W/m·K |
Furan-resin impregnated graphite | Pick when service is hotter (to ~190–200 °C) or contains alkali/solvent mixtures that swell phenolic. | — | 24 | 0.3 | 25 HV | 110 W/m·K |
PHDefaultThis page Pre-hardened | Standard choice for hydrochloric/sulfuric/phosphoric acid heat exchangers and columns up to about 170 °C. | — | 25 | 0.3 | 50 HV | 125 W/m·K |
What is Impervious Graphite PH?
Impervious Graphite PH is Impervious Graphite heat treated to PH — standard choice for hydrochloric/sulfuric/phosphoric acid heat exchangers and columns up to about 170 °C. Impervious Graphite PH has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. Elongation at break is 0.3% and the elastic modulus is 12 GPa (1.74 Msi). Impervious Graphite PH has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 89% of ceramic grades.
Advantages
- Ductile — tolerates forming and impact — 0.3%, better than 91% of ceramic grades
- Conducts heat well — 125 W/m·K (72.2 BTU/hr·ft·°F), better than 90% of ceramic grades
- Lightweight — 1.8 g/cm³ (0.065 lb/in³), better than 89% of ceramic grades
- Easy to machine — 80/100, better than 89% of ceramic grades
- Good corrosion resistance — 88/100, better than 77% of ceramic grades
Limitations
- Low stiffness — 12 GPa (1.74 Msi), worse than 89% of ceramic grades
- Hard to polish — 45/100, worse than 88% of ceramic grades
- Limited service temperature — 170°C (338 °F), worse than 87% of ceramic grades
Impervious Graphite PH properties
Typical room-temperature values for Impervious Graphite PH; 15 are specific to this condition. Other listed values are Impervious Graphite reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical2
Impervious Graphite PH has a density of 1.8 g/cm³ (0.065 lb/in³), lighter than 89% of ceramic grades.
Mechanical10
Impervious Graphite PH has a tensile strength of 25 MPa (3.63 ksi), weaker than 85% of ceramic grades. Elongation at break is 0.3% and the elastic modulus is 12 GPa (1.74 Msi).
Thermal5
Impervious Graphite PH is rated for continuous service to 170°C (338 °F). It conducts heat at 125 W/m·K (72.2 BTU/hr·ft·°F), better than 90% of ceramic grades. Thermal expansion is 4.5 µm/m·K (2.5 µin/in·°F).
Electrical2
Impervious Graphite PH has an electrical resistivity of 1.2×10⁻⁵ Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (88/100), better than 77% of ceramic grades.
Sustainability3
Producing a kilogram of Impervious Graphite PH takes about 190 MJ of energy and emits 14 kg of CO₂ — more than 62% of ceramic grades. Typical recycled content is 0%.
Manufacturability3
Impervious Graphite PH's machinability is very good (80/100, better than 89% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Impervious Graphite PH
Is Impervious Graphite easy to machine?
Machines fast with carbide or PCD dry-cut tooling, but dust is abrasive and electrically conductive — vacuum extraction and sharp positive-rake tools are mandatory to avoid edge chipping.
Can Impervious Graphite be welded?
Not weldable; joints are made with corrosion-resistant carbon-filled resin cements or mechanically flanged with PTFE gaskets.
Can Impervious Graphite be formed, bent or molded?
Shape is produced by extrusion/moulding or isostatic pressing of the green body, baking and graphitising, then vacuum-pressure resin impregnation and cure — no post-cure forming is possible.
What surface finishes work on Impervious Graphite?
Surfaces are ground or lapped; no coating is normally used, and any surface resin skin should be removed to expose the impregnated body for good heat transfer.
Impervious Graphite chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| phenolic or furan resinimpregnant, cured; PTFE in the fluoropolymer variant | 10 – 18 | 14 |
| ashtypical for corrosion grades | 0 – 0.3 | 0.1 |
| S | 0 – 0.05 | 0.02 |
| C (graphite matrix)graphitised petroleum-coke / pitch body | ≥ 82 (balance) | — |
Impervious Graphite PH — frequently asked
What is Impervious Graphite PH used for?
Impervious Graphite PH is typically used for heat exchangers, acid coolers, reaction vessels and chemical process piping. In short: zero-porosity acid-service graphite; high conductivity, acid-proof; resin limits use to 170 °C.
What is the tensile strength of Impervious Graphite PH?
Impervious Graphite PH has a typical tensile strength of 25 MPa (3.63 ksi) — weaker than 85% of ceramic grades. Strength varies by condition: see the 3 listed tempers.
Is Impervious Graphite PH easy to machine?
Yes — machinability is rated very good (80/100, better than 89% of ceramic grades). Machines fast with carbide or PCD dry-cut tooling, but dust is abrasive and electrically conductive — vacuum extraction and sharp positive-rake tools are mandatory to avoid edge chipping.
Can Impervious Graphite PH be welded?
Not weldable; joints are made with corrosion-resistant carbon-filled resin cements or mechanically flanged with PTFE gaskets.
What surface finishes work on Impervious Graphite PH?
Surfaces are ground or lapped; no coating is normally used, and any surface resin skin should be removed to expose the impregnated body for good heat transfer.
Can Impervious Graphite PH be formed, bent or molded?
Shape is produced by extrusion/moulding or isostatic pressing of the green body, baking and graphitising, then vacuum-pressure resin impregnation and cure — no post-cure forming is possible.
What is the maximum service temperature of Impervious Graphite PH?
Impervious Graphite PH is rated for continuous use to about 170°C (338 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- Graphilor impervious graphite grades — Mersen (2022)
- DIABON impregnated graphite for process equipment — SGL Carbon (2021)
- ASM Engineered Materials Handbook Vol.4 — Ceramics and Glasses (carbon/graphite section) — ASM International (1991)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.