Monel 400 Slip-On Flanges for Corrosive Service

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Monel 400 slip-on flanges are nickel-copper alloy flanges designed for seawater, brine, alkali and hydrocarbon service where excellent corrosion resistance is required. Available in Monel 400 / UNS N04400 and related nickel alloy options, these flanges are widely used in marine, chemical, oil and gas, and power systems. SASA FLANGE supplies Monel 400 slip-on flanges with EN 10204 3.1 certificate, PMI testing and full heat traceability.

  • ✓Grade: Monel 400 / UNS N04400, Alloy 400, ASTM B564 UNS N04400, ASTM B127 plate-cut option
  • ✓Surface: Natural machined finish, pickled, passivated, protective oil coating, marking varnish
  • ✓Specification: DN15 to DN1500 (1/2 inch to 60 inch), Class 150 to 2500, PN6 to PN100

Description

Product Detail

Monel 400 slip-on flanges are forged or plate-cut flanges with a slightly larger bore than the pipe outside diameter, allowing the pipe to slip into the flange before fillet welding. This design offers easy alignment and economical installation while Monel 400 provides excellent resistance to seawater, hydrofluoric acid, alkalis, neutral and salt solutions. These flanges are commonly used in marine piping, offshore platforms, chemical process lines, brine systems and heat exchange equipment.

SASA FLANGE supplies Monel 400 slip-on flanges in standard and customized sizes according to ASME, EN, DIN, JIS and GB requirements. Each order can be supported by chemical analysis, mechanical testing, dimensional inspection, PMI testing, EN 10204 3.1 certificate and full heat number traceability to ensure reliable performance in critical industrial service.

  • ✓Product Name: Monel 400 Slip-On Flanges
  • ✓Material Grade: Monel 400 / UNS N04400
  • ✓Product Type: Slip-On Flange, raised face or flat face, forged or plate machined
  • ✓Main Feature: Excellent resistance to seawater, alkalis and many reducing media with easy installation
  • ✓Applications: Marine piping, offshore systems, chemical processing, oil and gas, power and desalination

Product Parameters

Product Name Monel 400 Slip-On Flanges
Material Grade Monel 400 / UNS N04400 / Alloy 400
Material Type Nickel-Copper Alloy
Product Form Forged flange, rolled ring flange, plate machined flange
Size Range DN15 – DN1500 (1/2 inch – 60 inch)
Pressure Class Class 150 – 2500 / PN6 – PN100
Sealing Face RF, FF, RTJ, TG, MFM
Surface Treatment Natural machined, pickled, passivated, protective oil coating
Standard ASME B16.5, ASME B16.47, EN 1092-1, DIN, JIS B2220, GB/T 9119 or customer specification
Inspection Chemical Analysis, Mechanical Test, PMI Test, Dimensional, Hydrostatic
Certificate EN 10204 3.1 Material Certificate available
Processing Service Cutting, CNC Machining, Custom Drilling, Custom Size Processing

Chemical Composition

The following chemical composition is for reference for Monel 400 material commonly used in slip-on flanges. Exact chemistry may vary slightly by product form, manufacturing route and applicable ASTM or EN specification. Final supplied composition will follow the relevant standard, purchase order requirements and the original material test certificate.

Element C Si Mn P S Cr Ni Mo Other
Content % 0.30 max 0.50 max 2.00 max 0.024 max 0.024 max 0.50 max 63.0 min 0.50 max Cu 28.0-34.0, Fe 2.50 max

Mechanical Properties

Mechanical properties shown below are typical reference values for Monel 400 used in flange manufacturing. Actual values can vary with forging condition, annealed or stress-relieved state, thickness and the governing product specification. Certified test results are confirmed by material test reports and can be verified against project requirements before shipment.

Grade Tensile Strength Yield Strength Elongation Hardness Density
Monel 400 Annealed 550 MPa min 240 MPa min 35% min 150-190 HB 8.80 g/cm3
Monel 400 Forged Flange 585 MPa min 245 MPa min 30% min 160-210 HB 8.80 g/cm3

Common Size Table

Size Range Pressure Class Sealing Face Material Availability
DN15 – DN50 Class 150 – 600 RF Monel 400 / UNS N04400 Stock / Production
DN65 – DN300 Class 150 – 1500 RF / RTJ Monel 400 / UNS N04400 Stock / Production
DN350 – DN600 Class 150 – 2500 RF / RTJ Monel 400 / UNS N04400 Production
DN700 – DN1500 Class 150 – 900 RF Monel 400 / UNS N04400 Made to Order

Different Specifications Comparison

Type Description Typical Use
ASME B16.5 Slip-On RF Raised face slip-on flange for small to medium pipe sizes with easy fit-up and fillet welding General process piping, chemical lines, seawater service
ASME B16.5 Slip-On FF Flat face slip-on flange designed for mating with flat face valves, pumps or non-metallic equipment flanges Low pressure utility systems and lined equipment connections
ASME B16.5 Slip-On RTJ Ring type joint slip-on flange for higher pressure service requiring metal-to-metal gasket sealing Oil and gas, offshore, high pressure hydrocarbon lines
EN 1092-1 Type 12 Slip-On European standard slip-on plate or forged flange with PN pressure ratings and metric dimensions Water treatment, chemical plants, marine and export projects

Equivalent Standards and International Names

Monel 400 is internationally recognized as a nickel-copper corrosion resistant alloy and may be supplied to multiple dimensional standards depending on project location. While flange dimensions follow ASME, EN, DIN, JIS or GB standards, the material is commonly identified as UNS N04400 or Alloy 400. Equivalent naming and dimensional compatibility should be confirmed at quotation stage.

Standard / Region Standard Code Typical Grade / Equivalent
USA ASME B16.5 Monel 400 / UNS N04400
Europe EN 1092-1 Alloy 400 / NiCu30Fe
Germany DIN 2527 / 2566 Werkstoff 2.4360 equivalent application
Japan JIS B2220 Monel 400 / N04400 equivalent material
China GB/T 9119 Monel 400 / UNS N04400 nickel alloy flange

Production Process Flow

Monel 400 slip-on flanges are produced under controlled manufacturing procedures to ensure corrosion resistance, dimensional accuracy and traceable quality. From raw material selection to final inspection, each process step is monitored to meet international flange standards and project specifications.

  • 1. Raw Material Selection
  • 2. Forging / Cutting
  • 3. Heat Treatment
  • 4. Rough Machining
  • 5. Finish Machining
  • 6. Drilling
  • 7. Surface Treatment
  • 8. Inspection
  • 9. Marking
  • 10. Packing
  • 11. Delivery
Process Step Description Quality Control Point
Raw Material Select certified forging billets or plates Material certificate and traceability
Forging Hot forging to achieve required shape Forging temperature and reduction ratio
Heat Treatment Solution annealing or stress relieving as required Temperature and holding time control
Machining Sealing face, bolt holes, dimensions Dimensional accuracy and surface finish
Inspection Final inspection before shipment Dimension, surface, PMI, hydrostatic

Product Inspection

1. Chemical Composition Inspection

Chemical composition inspection is carried out using spectrometer analysis to verify that the Monel 400 flange meets the required nickel, copper, iron and controlled impurity limits. This step confirms compliance with UNS N04400 chemistry before machining or shipment and helps ensure corrosion resistance in marine, chemical and offshore environments.

2. Mechanical Properties Testing

Mechanical testing verifies tensile strength, yield strength, elongation and hardness of the Monel 400 material used for the flange. Test values are checked against the applicable material specification and purchase requirements. This inspection helps confirm that the flange has adequate strength, ductility and reliability for pressure piping service.

3. Dimensional Inspection

Dimensional inspection covers outside diameter, bore size, thickness, bolt circle, hole diameter, bolt hole quantity, flange height and facing details. Raised face or ring joint dimensions are checked with calibrated instruments to ensure full compliance with ASME, EN, DIN, JIS or GB standards and proper interchangeability during installation.

4. PMI Testing and Hydrostatic Testing

Positive Material Identification is performed to confirm the flange material is genuine Monel 400 and not substituted with another nickel alloy or stainless steel. Hydrostatic testing can be arranged when project specifications require pressure verification. EN 10204 3.1 certificate, material test reports and traceable heat numbers are supplied with shipment documentation.

Product Packaging

  • ✓Wooden Case Packaging: Suitable for high-pressure and large-diameter products
  • ✓Pallet Packing with Shrink Wrap: Suitable for batch shipments and standard sizes
  • ✓Anti-rust Oil Coating + Waterproof Paper: Used for ocean freight protection
  • ✓Individual Plastic Bag + Carton: Used for small fittings and threaded products
  • ✓Clear Marking: Grade, size, pressure class, heat number and PO number

Applications

Monel 400 slip-on flanges are selected for piping systems exposed to seawater, salt brines, alkalis and many reducing chemicals. Their combination of corrosion resistance, good strength and practical installation makes them suitable for demanding industrial projects where long service life and dependable sealing performance are required.

Industry Typical Applications Why This Product Is Used
Oil and Gas Produced water lines, offshore utility piping, brine injection systems, sour water service Good resistance to chloride-bearing media and marine environments with reliable flange joint performance
Chemical Processing Alkali handling, hydrofluoric acid systems, salt production, reactor and transfer piping Monel 400 offers strong resistance to caustic solutions and many reducing chemical media
Power Generation Condenser systems, feedwater auxiliaries, heat exchanger piping and coastal plant utilities Provides corrosion resistance in wet, saline and elevated temperature service conditions
Water Treatment Desalination units, brine circulation lines, seawater intake and discharge piping Excellent seawater resistance helps reduce maintenance and extend operating life
Marine and Offshore Shipboard piping, firewater systems, ballast lines, offshore module piping High resistance to seawater corrosion and good mechanical performance in marine service

Why Choose SASA FLANGE?

  • ✓Professional manufacturer of Slip-On Flanges for global industrial projects
  • ✓Customized size, pressure class and material grade according to drawings
  • ✓Full standard support: ASME, EN, DIN, JIS, GB, GOST and customer specifications
  • ✓Material traceability with heat number control and EN 10204 3.1 material certificate
  • ✓Chemical analysis, mechanical testing, PMI testing, hydrostatic and dimensional inspection
  • ✓Stock availability for standard items, lead time 3-7 days; custom production 15-30 days
  • ✓Export-grade packaging for sea, air and land transportation
  • ✓15+ years experience supplying 50+ countries worldwide

FAQ

Q: What is a Monel 400 slip-on flange?

A: A Monel 400 slip-on flange is a nickel-copper alloy flange with a bore slightly larger than the pipe outside diameter, allowing the pipe to slide into position before welding. It is valued for easy installation and excellent resistance to seawater, brine, alkalis and many corrosive industrial media used in marine and chemical systems.

Q: What materials are available for Monel 400 slip-on flanges?

A: The standard material is Monel 400, also known as Alloy 400 or UNS N04400. Depending on project requirements, SASA FLANGE can also discuss related nickel alloy flange options, plate-machined or forged forms, and dimensional production to ASME, EN, DIN, JIS or GB standards with full material traceability and certification.

Q: What pressure class is supported?

A: SASA FLANGE supplies Monel 400 slip-on flanges in common pressure ratings including ASME Class 150, 300, 600, 900, 1500 and up to 2500, as well as EN and DIN pressure ratings such as PN10, PN16, PN25, PN40, PN63 and PN100. Available rating depends on size, standard and face type.

Q: Can SASA FLANGE supply custom sizes?

A: Yes. SASA FLANGE can produce custom Monel 400 slip-on flanges based on drawings or project specifications. Custom service includes non-standard outer diameter, bore size, drilling pattern, facing type such as RF, FF or RTJ, special marking, and machining to match valves, pumps, lined pipe or special alloy piping systems.

Q: What certificate is provided?

A: Monel 400 slip-on flanges can be supplied with EN 10204 3.1 material certificate, original MTC, heat number traceability and PMI records. When specified, SASA FLANGE also provides dimensional reports, chemical analysis, mechanical test results and hydrostatic test records so buyers have complete documentation for project approval and inspection.

Contact Us

If you are looking for monel 400 flanges or related custom flange products, please contact SASA FLANGE with your required size, pressure class, material grade, standard, surface treatment, quantity and inspection requirements. Our team will provide professional technical solutions and competitive quotation within 24 hours.

  • 📧 Email: sales@sasaflange.com
  • 📱 WhatsApp: +86 13764965049
  • ☎️ Tel: +86 21 52236361
  • 🌐 Website: www.sasaflange.com

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