Description
Nickel-iron-chromium-molybdenum-copper alloy industrial valve
Incoloy 825 Triple Offset Butterfly Valve
A versatile nickel alloy valve material for acid, pickling, oil-and-gas and pollution-control systems. The triple offset butterfly valve configuration is engineered for compact high-temperature or severe-service process isolation.
What is a Incoloy 825 Triple Offset Butterfly Valve?
A Incoloy 825 Triple Offset Butterfly Valve combines a nickel-iron-chromium alloy containing molybdenum, copper and titanium for resistance in reducing and oxidizing acids and selected chloride environments with a quarter-turn metal-seated design using three geometric offsets to reduce seat rubbing and support severe-service isolation.
N08825 is selected from actual acid concentration, temperature, chloride, oxidizer and reducing-condition data. Seat-stack design, pressure direction, leakage class, shaft loading, thermal cycling and actuator torque are configuration-specific.
Incoloy 825 Triple Offset Butterfly Valve specifications
| Product | Incoloy 825 Triple Offset Butterfly Valve |
|---|---|
| Valve construction | Triple-eccentric metal-seated butterfly valve in wafer, lug, double-flanged or butt-weld body pattern |
| Nominal material | Incoloy 825 |
| UNS / EN reference | UNS N08825; EN 2.4858 |
| Product forms | Wrought/forged ASTM B564 or B462 UNS N08825 as applicable; cast body grade separately selected and project-approved |
| Design standards | API 609 and ASME B16.34; EN 593 option for applicable European projects |
| Pressure testing | API 598, EN 12266-1 or project-specified shell and seat testing |
| Pressure rating | ASME Class or PN rating verified against exact material, size, construction and design temperature |
| End connections | Wafer, lug, double-flanged or butt-weld body patterns according to design |
| Operation | Gearbox, pneumatic, electric or hydraulic actuator |
| Documentation | EN 10204 3.1 material records, pressure test report, GA drawing and project inspection records as ordered |
This is an engineered inquiry product, not a universal stock specification. Final availability depends on valve size, pressure class, material form, trim, seat system, operator, quantity and required code edition.
Incoloy 825 material selection
| Selection point | Engineering guidance |
|---|---|
| Material profile | a nickel-iron-chromium alloy containing molybdenum, copper and titanium for resistance in reducing and oxidizing acids and selected chloride environments |
| Why it is selected | Balanced resistance to sulfuric and phosphoric acids, reducing/oxidizing conditions and selected localized corrosion. |
| Typical service | Acid production, pickling, chemical processing, sour oil and gas, pollution control and nuclear fuel-related processes. |
| Limitations to check | It is not a universal seawater or hydrochloric-acid alloy. Product condition, welding and service-specific corrosion data remain essential. |
| Specification route | Wrought/forged ASTM B564 or B462 UNS N08825 as applicable; cast body grade separately selected and project-approved |
| Verification | PMI for nickel, chromium, molybdenum and copper, heat traceability and verification of the exact product specification. |
Triple Offset Butterfly Valve design and standards
API 609
Common design basis for butterfly valves; category, body pattern, seat design and edition must be identified.
ASME B16.34
Pressure-temperature and general valve design requirements where applicable.
API 598 / EN 12266-1
Shell and seat testing selected for the applicable project and market.
API 607 / ISO 10497
Fire-safe qualification applies only to the exact seat, seal and valve configuration.
Seal ring, seat stack, pressure direction, shaft/packing system, bearing loads and actuator safety factor must be reviewed as a complete package.
Fire-safe, fugitive-emission, sour-service, oxygen, cryogenic, chlorine and PED requirements apply only when explicitly defined and supported for the exact offered configuration.
Typical applications
| Industry | Material service context | Valve selection focus |
|---|---|---|
| Chemical processing | Sulfuric/phosphoric acid and mixed process systems after review | Pressure direction, leakage class, metal-seat design, temperature, torque and fire-safe/emissions qualification |
| Pickling | Acid cleaning and recovery equipment | Pressure direction, leakage class, metal-seat design, temperature, torque and fire-safe/emissions qualification |
| Oil and gas | Selected sour and chloride-bearing production systems | Pressure direction, leakage class, metal-seat design, temperature, torque and fire-safe/emissions qualification |
| Pollution control | Scrubbers, waste treatment and corrosive off-gas support systems | Pressure direction, leakage class, metal-seat design, temperature, torque and fire-safe/emissions qualification |
Application examples are not a corrosion or design approval. The end user must verify process chemistry, contaminants, pressure, temperature, velocity, cycling, emissions and regulatory requirements.
Quality, testing and traceability
Heat-number traceability and EN 10204 3.1 records matched to the ordered component specifications.
PMI for nickel, chromium, molybdenum and copper, heat traceability and verification of the exact product specification.
API 598, EN 12266-1 or project-specified shell and seat testing, with acceptance and leakage criteria stated on the order.
GA drawing, dimensions, marking, operation, pressure test and specified NDE/third-party records.
RFQ checklist
- Valve design standard and required edition
- Nominal size and ASME Class or PN rating
- Exact material specifications for pressure boundary, trim, seats, packing and bolting
- Body pattern, face-to-face, pressure direction, leakage class, seal-ring design and actuation
- End connection, facing and face-to-face requirement
- Fluid composition, concentration, contaminants and solids
- Design and operating pressure/temperature
- PMI, corrosion testing, NDE, witnessing and document requirements
Frequently asked questions
What is the standard designation for Incoloy 825?
UNS N08825 is the standardized alloy designation commonly marketed as Incoloy 825. EN 2.4858 is a commonly referenced European material number.
How does Alloy 825 differ from Alloy 625?
825 has a nickel-iron-chromium base with copper and titanium and is widely used in acid service. 625 has higher nickel with niobium and generally offers greater strength.
Can a cast body be ordered as N08825 without further detail?
No. N08825 normally identifies wrought product. A cast pressure body needs an approved casting grade and specification that meet the project chemistry, properties and corrosion requirements.
What are the three offsets?
They separate the shaft from the seat and body centerlines and add a conical sealing geometry, allowing rapid seat disengagement during opening.
Is every triple offset butterfly valve bidirectional?
No. Some designs have a preferred pressure direction or different leakage capability by direction. Confirm the tested performance of the exact configuration.
Can Incoloy 825 be used for every component in this triple offset butterfly valve?
Not automatically. Pressure-boundary, trim, stem or shaft, seating, packing, gasket and bolting materials have different mechanical and corrosion duties. The complete bill of materials must be engineered for the service.
Related Incoloy 825 valve products
Need a broader comparison? View the general stainless steel and alloy butterfly valves guide or browse all Butterfly Valves.
Request a Incoloy 825 Triple Offset Butterfly Valve quotation
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