2-Inch

Export-Ready for Offshore, Marine & Global Markets

origin Mumbai (JNPT) | CIF worldwide ports | API 600 / API 6D compliant | EN 10204 3.1/3.2 material certs

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NAB Isolation Valve — 2" Class 150 Flanged

Supreme Valves India manufactures NAB (Nickel Aluminium Bronze, C95800) isolation valves for the most demanding marine and offshore environments. The 2" Class 150 flanged isolation valve combines the exceptional seawater corrosion resistance of NAB with proven API 600/OS&Y gate valve design for reliable, maintenance-free isolation service on FPSOs, offshore platforms, desalination plants, and naval vessels. The valve features a flexible wedge gate, Graphite gland packing, and flanged RF connections per ASME B16.5. Available in gate, globe, and ball valve patterns to meet project specifications.

NAB C95800 — Material Properties

≥585 MPa

Tensile Strength

≥250 MPa

Yield Strength (0.2%)

≥12%

Elongation

≤170 HB

Hardness

Materials of Construction (MOC)

Component Material Specification
Body & Bonnet Nickel Aluminum Bronze (ASTM B148 C95800)
Stem / Spindle Monel 400 / K500
Seat / Trim NAB / PTFE / Viton

Technical Specifications

Parameter Specification / Standard
Manufacturing / Design Standard API 609 / API 600 / ASME B16.34
Testing Standard API 598 / EN 12266-1
Pressure Rating Class 150 / Class 300 / PN16

Material of Construction

S.N.Parts NameMaterialQty
1BodyInvestment Casting (ASTM A 351 Gr. CF8/CF8M)1
2DiscInvestment Casting (ASTM A 351 Gr. CF8/CF8M)1
3SpringS.S.304 / S.S.3161
4Spring WasherS.S.304 / S.S.3161

Testing Details & Standards

  • Class: PN-40
  • Hydro Test Pressure Body: 60 Kg/cm²
  • Seat: 44 Kg/cm²
  • Duration: 1 Minute

Dimension Tables

SizeInchM.M.ØDØD1ØD2L
1/2"1/2"1515386016
3/4"3/4"2020477020
1"1"2524558022
1.1/2"1.1/2"40397510032
2"2"50509311540
2.1/2"2.1/2"656510914246
3"3"807612715450
4"4"1009814818460
5"5"12512517722569.5
6"6"15015020223074
8"8"200201266333140

Frequently Asked Questions

What is Nickel Aluminium Bronze (NAB) and why use it for valves?

Nickel Aluminium Bronze (NAB, UNS C95800) is a copper-based alloy containing approximately 9% aluminium, 4% nickel, and 4% iron. It offers exceptional resistance to seawater corrosion, biofouling, and erosion-corrosion — making it the material of choice for marine, offshore, and naval valve applications. NAB valves outperform brass, bronze, and even stainless steel in seawater service due to the formation of a stable, adherent oxide film that resists chloride attack. They are widely specified in FPSOs, subsea manifolds, desalination plants, and naval shipboard systems.

What is the pressure-temperature rating of a Class 150 NAB valve?

A Class 150 NAB valve is rated for a maximum working pressure of 285 PSI (19.6 bar) at 38°C (100°F) in accordance with ASME B16.34. As temperature increases, the allowable pressure decreases. At 200°C (392°F), the rating reduces to approximately 195 PSI. NAB retains its mechanical properties at elevated temperatures up to 250°C. Always consult the manufacturer's pressure-temperature chart for your specific service conditions.

What end connections are available for NAB isolation valves?

NAB isolation valves are available in flanged RF (Raised Face), RTJ (Ring Type Joint), butt weld, and socket weld ends. The most common for marine and offshore applications is flanged RF per ASME B16.5. Flanged RF is preferred for ease of maintenance and gasket replacement on shipboard and platform installations where periodic valve servicing is required. RTJ is specified for high-pressure/high-temperature (HPHT) offshore wells.

How does NAB compare to super duplex stainless steel for seawater service?

Both NAB and super duplex stainless steel (SDSS, UNS S32750/S32760) offer excellent seawater resistance. NAB is generally preferred for: (1) Seawater temperatures above 30°C where SDSS can suffer from crevice corrosion, (2) Zero-biofouling requirements (NAB's algaecidal properties inhibit marine growth), (3) High-velocity flow areas (NAB has superior erosion resistance up to 15 m/s). SDSS has higher yield strength and is preferred for subsea applications below 500m water depth due to pressure considerations. SDSS is typically more cost-effective for large quantities.

What standards do NAB isolation valves comply with?

NAB isolation valves from Supreme Valves India comply with: API 600 (Steel Gate Valves — Flanged and Butt-Weld Ends) for gate valves, API 6D (Pipeline Valves) for ball and check valves, ASME B16.5 (Pipe Flanges and Flanged Fittings), ASME B16.34 (Valves — Flanged, Threaded, and Welding End), and MSS SP-55 (Quality Standard for Steel Castings). Material certifications to ASTM B148 (NAB castings) and EN 1982 (CuAl10Ni5Fe4) are available with 3.1/3.2 inspection certificates per EN 10204.