Source Spectacle Blind Flange from verified mills, manufacturers and stockists on MetalMitra. Options span all standard face types and pressure classes, and every order can ship with an EN 10204 3.1 certificate.

Spectacle Blind Flanges are manufactured in a figure-eight configuration, combining a solid blind section and an open spacer section. This design allows the pipeline to be positively isolated or opened by rotating the spectacle blind according to the operating requirement.

These flanges are available in multiple materials, pressure classes, dimensions and face configurations to suit different industrial piping requirements. Applications include process plants, oil & gas, petrochemical, chemical, power generation, marine, sugar, defence and general fabrication industries.

Products can be supplied for applications in oil & gas, petrochemical, refinery, chemical processing, power generation, marine, sugar, nuclear, defence and industrial fabrication.

Key properties

Positive Isolation — Designed for dependable physical isolation of piping lines.
Figure-Eight Design — Integrated blind and spacer arrangement for practical operation.
Pressure Classes — Available across multiple ASME pressure classes and DIN ratings.
Multiple Materials — Stainless, duplex, alloy, carbon and nickel alloy options.

Dimensions — ANSI Flanges, ASME Flanges, BS Flanges, DIN Flanges, EN Flanges and custom dimensions.

Standards — ANSI B16.5, ANSI B16.47 Series A & B, MSS SP44, ASA, API-605, AWWA and custom drawings.

Pressure Class — 150 LBS, 300 LBS, 600 LBS, 900 LBS, 1500 LBS and 2500 LBS.

DIN Pressure Ratings — ND-6, ND-10, ND-16, ND-25 and ND-40.

Size Range — 1/2″ (15 NB) to 48″ (1200 NB).

Flange Face — Flat Face (FF), Raised Face (RF) and Ring Type Joint (RTJ).

Applicable Standards

DIN Standards — DIN 2527, DIN 2566, DIN 2573, DIN 2576, DIN 2641, DIN 2642, DIN 2655, DIN 2656, DIN 2627, DIN 2628, DIN 2629, DIN 2631, DIN 2632, DIN 2633, DIN 2634, DIN 2635, DIN 2636, DIN 2637, DIN 2638 and DIN 2673.

ANSI / ASME Standards — ANSI B16.5, ANSI B16.47, MSS SP44, ANSI B16.36 and ANSI B16.48.

BS Standards — BS 4504, BS 1560 and BS 10.

Materials & Grades

Stainless Steel — ASTM A182 / A240 F304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H and 904L.

Duplex & Super Duplex — ASTM / ASME A/SA 182 F44, F45, F51, F53, F55, F60 and F61.

Alloy Steel — ASTM / ASME A/SA 182 and A387 F1, F5, F9, F11, F12, F22 and F91.

Carbon Steel — ASTM / ASME A/SA 105, A350, A181 LF2, A516 Gr.70, A36, A694 F42, F46, F52, F60, F65 and F706.

Nickel Alloys — ASTM SB564, SB160, SB472, SB162; Nickel 200/201, Monel 400/500, Inconel 600/601/625/800/825, Hastelloy C276 and Alloy 20.

Copper Alloys — ASTM SB61, SB62, SB151, SB152; Cu-Ni 90/10, Cu-Ni 70/30 and selected copper alloy UNS grades.

Detailed Material Selection

Material Category	Applicable Material / Grade	Typical Material Standard
Stainless Steel	F304, 304L, 304H, 316, 316L, 316Ti, 310, 310S, 321, 321H, 317, 347, 347H, 904L	ASTM A182 / A240
Duplex / Super Duplex	F44, F45, F51, F53, F55, F60, F61	ASTM / ASME A/SA 182
Alloy Steel	F1, F5, F9, F11, F12, F22, F91	ASTM / ASME A/SA 182 / A387
Carbon Steel	A105, A350, LF2, A516 Gr.70, A36, A694 F42/F46/F52/F60/F65/F706	ASTM / ASME
Nickel Alloys	Nickel 200/201, Monel 400/500, Inconel 600/601/625/800/825, Hastelloy C276, Alloy 20	ASTM SB / relevant alloy specifications
Copper Alloys	Cu-Ni 90/10, Cu-Ni 70/30, C10100, C10200, C10300, C10800, C12000, C12200	ASTM SB61 / SB62 / SB151 / SB152

Class 150 Spectacle Blinds

Dimensional data for Class 150 Spectacle Blinds as provided for the listed nominal pipe sizes.

NPS	Outside Ø A	Inside Ø B	Centerline C	Thickness t	Web Width W
1/2	45	16	60	3	38
3/4	54	21	70	3	38
1	64	27	80	3	38
1¼	73	42	90	6.4	38
1½	83	48	100	6.4	38
2	102	61	120	6.4	51
2½	107	73	140	6.4	51
3	133	89	150	6.4	64
3½	159	102	175	9.7	64
4	172	114	190	9.7	64
5	194	141	215	9.7	76
6	219	168	240	12.7	76
8	276	219	300	12.7	76
10	337	273	360	15.7	102
12	406	324	430	19.1	102
14	448	356	475	19.1	108
16	511	406	460	22.4	108
18	546	457	580	25.4	114
20	603	508	635	28.4	121
24	714	610	750	31.8	140

Flat Face — FF — Flat-face configuration for applications where the mating flange arrangement requires a flat sealing surface.

Raised Face — RF — Raised-face configuration commonly selected for industrial pressure piping and process applications.

Ring Type Joint — RTJ — Ring-type joint configuration for demanding pressure and sealing applications where specified by the piping design.

Applications & industries

Oil & Gas
Petrochemical Plants
Chemical Processing
Power Generation
Refineries
Marine Industry
Sugar Industry
Nuclear Applications
Defence
Process Piping
Industrial Fabrication
Pressure Piping Systems

Testing & documentation

Inspection and documentation for Spectacle Blind Flange follow the applicable standard plus any extra requirements in your PO.

Dimensional inspection
Material identification and traceability
Visual and surface inspection
Material Test Certificate documentation
Heat number traceability where specified
Third-party inspection support as required
Custom drawings and technical documentation

Why source on MetalMitra

Verified suppliers — Mills, manufacturers and stockists are reviewed by the MetalMitra team before they list.
One RFQ, several quotes — Share size, grade and quantity once and compare offers side by side.
Full traceability — Heat numbers, EN 10204 3.1 MTCs and third-party inspection on request.
Delivered worldwide — Export-worthy packing and shipping to India, the Middle East, Africa, Europe and the Americas.

Request pricing

Post an RFQ for Spectacle Blind Flange with your drawing or specification and receive quotes from verified suppliers.

Technical note: Values on this page are for reference. Always confirm against the governing standard, your purchase specification and the mill test certificate.

Spectacle Blind Flange

Key properties