Name: NAB Isolation Valve 2" Class 150 Flanged
Brand: Supreme Valves India
SKU: NAB-ISO-2IN-150
Availability: InStock
Rating: 4.8 (127 reviews)

Question 1

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

Accepted Answer

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.

Question 2

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

Accepted Answer

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.

Question 3

What end connections are available for NAB isolation valves?

Accepted Answer

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.

Question 4

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

Accepted Answer

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.

Question 5

What standards do NAB isolation valves comply with?

Accepted Answer

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.

Question 6

What are the typical Production schedule and export terms for NAB valves?

Accepted Answer

NAB valves are cast to order, with a typical Production schedule of 6–10 weeks for sizes 1/2" to 6". Material certification (3.1 EN 10204 or 3.2) and special testing (hydrostatic, PMI, UT) may add 3–5 working days. Export packaging follows ISPM 15 standards for wood crating. We ship origin Mumbai Nhava Sheva (JNPT) or CFR/CIF to destination port worldwide. For urgent offshore projects, air freight from Ahmedabad airport is available.

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

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

S.N.	Parts Name	Material	Qty
1	Body	Investment Casting (ASTM A 351 Gr. CF8/CF8M)	1
2	Disc	Investment Casting (ASTM A 351 Gr. CF8/CF8M)	1
3	Spring	S.S.304 / S.S.316	1
4	Spring Washer	S.S.304 / S.S.316	1

Size	Inch	M.M.	ØD	ØD1	ØD2	L
1/2"	1/2"	15	15	38	60	16
3/4"	3/4"	20	20	47	70	20
1"	1"	25	24	55	80	22
1.1/2"	1.1/2"	40	39	75	100	32
2"	2"	50	50	93	115	40
2.1/2"	2.1/2"	65	65	109	142	46
3"	3"	80	76	127	154	50
4"	4"	100	98	148	184	60
5"	5"	125	125	177	225	69.5
6"	6"	150	150	202	230	74
8"	8"	200	201	266	333	140

2-Inch

NAB Isolation Valve — 2" Class 150 Flanged

NAB C95800 — Material Properties

Materials of Construction (MOC)

Technical Specifications

Material of Construction

Testing Details & Standards

Dimension Tables