Description
Nickel-iron-chromium-molybdenum-copper alloy industrial valve
Incoloy 825 Swing Check Valve
A versatile nickel alloy valve material for acid, pickling, oil-and-gas and pollution-control systems. The swing check valve configuration is engineered for backflow prevention in steady-flow process and utility lines.
What is a Incoloy 825 Swing Check Valve?
A Incoloy 825 Swing Check Valve combines a nickel-iron-chromium alloy containing molybdenum, copper and titanium for resistance in reducing and oxidizing acids and selected chloride environments with an automatic non-return design whose hinged disc opens with forward flow and closes as flow decelerates or reverses.
N08825 is selected from actual acid concentration, temperature, chloride, oxidizer and reducing-condition data. Check valves should be sized from minimum, normal and maximum flow plus transient behavior rather than automatically matching the pipe size.
Incoloy 825 Swing Check Valve specifications
| Product | Incoloy 825 Swing Check Valve |
|---|---|
| Valve construction | Bolted-cover swing check valve with hinged disc and service-specific seat/hinge arrangement |
| 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 594 and ASME B16.34; API 6D only for specifically designed pipeline-service valves |
| Pressure testing | API 598 or project-specified shell and closure testing |
| Pressure rating | ASME Class or PN rating verified against exact material, size, construction and design temperature |
| End connections | RF/RTJ flanged or butt-weld ends according to design |
| Operation | Automatic; external lever/weight, spring assist or dashpot only when engineered |
| 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. |
Swing Check Valve design and standards
API 594
Common design and testing basis for check valves within its scope.
ASME B16.34
Pressure-temperature, material and general valve design requirements within scope.
API 598
Shell and closure pressure-testing basis when specified.
API 6D
Pipeline-service requirements apply only to valves specifically designed and documented to API 6D.
Disc stability, minimum velocity, pressure drop, orientation, pump trip and system transients affect slam risk and service life.
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 | Minimum stable velocity, orientation, pressure drop, disc dynamics, closure leakage and transient control |
| Pickling | Acid cleaning and recovery equipment | Minimum stable velocity, orientation, pressure drop, disc dynamics, closure leakage and transient control |
| Oil and gas | Selected sour and chloride-bearing production systems | Minimum stable velocity, orientation, pressure drop, disc dynamics, closure leakage and transient control |
| Pollution control | Scrubbers, waste treatment and corrosive off-gas support systems | Minimum stable velocity, orientation, pressure drop, disc dynamics, closure leakage and transient control |
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 or project-specified shell and closure 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
- Minimum/normal/maximum flow, fluid properties, line orientation and pump/system transient data
- 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 causes swing check valve slam?
Oversizing, low velocity, excessive disc travel and rapid flow reversal can cause impact closure. Correct hydraulic sizing and transient review are essential.
Can a swing check valve be installed vertically?
Only when approved for vertical upward flow and the operating velocity can open and stabilize the disc. Follow the qualified design and installation instructions.
Can Incoloy 825 be used for every component in this swing check 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 check valves guide or browse all Check Valves.
Request a Incoloy 825 Swing Check Valve quotation
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