OEM manufacturer ASME B16.5 · ASME B16.47 · EN 1092-1 Type 05
Blind Flanges — ASME B16.5 & B16.47
A blind flange is a solid flange with no bore, used to close the end of a pipe, valve or vessel nozzle. Teshi Group manufactures blind flanges to ASME B16.5, ASME B16.47 Series A/B and EN 1092-1 Type 05 in carbon, stainless, alloy and duplex steels.
Also called: BL flange, BLRF flange, blank flange, blind raised face flange
What is a Blind Flange?
A blind (BL) flange is a solid disc drilled with the standard bolt pattern of its class, bolted against a mating flange to seal a line end. It carries the full pressure load as a plate in bending, together with bolt loads, so it is generally the most highly stressed flange type in larger sizes. Blind flanges close pipe ends and nozzles, isolate sections for pressure testing, and provide access points that can be opened for inspection or cleaning. They can be supplied drilled and tapped for a vent, drain or instrument connection when specified.
Key features
- Solid forged disc; no bore
- Same OD, bolt circle and drilling as the mating flange of the same class
- RF, FF or RTJ facing; RTJ groove machined to ASME B16.5 / B16.20
- Optional centre tapping (NPT or socket) for vent, drain or instrument
- Large sizes in B16.47 Series A or B
Specification
| Supply | OEM manufacturer — Teshi Group, India |
|---|---|
| Standard | ASME B16.5 (NPS ½″–24″); ASME B16.47 Series A/B (NPS 26″–60″); EN 1092-1 Type 05 |
| Pressure class | Class 150–2500 (B16.5); Class 75–900 (B16.47, by series); PN 2.5–PN 400 (EN 1092-1) |
| Facing | RF, FF, RTJ |
| Materials — carbon steel | ASTM A105 / A105N; ASTM A181 Cl 60, Cl 70; ASTM A266 Gr 2, Gr 4 (large forgings) |
| Materials — high-yield carbon steel | ASTM A694 F42, F46, F48, F50, F52, F56, F60, F65, F70 (MSS SP-44 grades F52–F70) |
| Materials — low-temperature carbon steel | ASTM A350 LF1, LF2 Cl 1, LF2 Cl 2, LF3, LF6, LF9 |
| Materials — alloy steel (Cr-Mo) | ASTM A182 F1, F2, F5, F5a, F9, F11 Cl 1 / 2 / 3, F12 Cl 1 / 2, F21, F22 Cl 1 / 3, F22V, F91, F92, F911; ASTM A336 F11, F22 (large forgings) |
| Materials — stainless steel | ASTM A182 F304, F304L, F304H, F304LN, F309H, F310, F316, F316L, F316H, F316LN, F316Ti, F317, F317L, F321, F321H, F347, F347H, F348 |
| Materials — 904L and 6Mo | 904L (ASTM A182 F904L, UNS N08904); 254 SMO / 6Mo (ASTM A182 F44, UNS S31254); AL-6XN (ASTM A182 F62, UNS N08367) |
| Materials — duplex stainless steel | ASTM A182 F51 (UNS S31803), F60 (UNS S32205, 2205) |
| Materials — super duplex stainless steel | ASTM A182 F53 (UNS S32750, 2507), F55 (UNS S32760), F61 (UNS S32550) |
| Materials — nickel alloys | ASTM B564 / B160 / B462: Nickel 200 / 201 (N02200 / N02201), Monel 400 (N04400), Monel K-500 (N05500), Inconel 600 (N06600), Inconel 625 (N06625), Inconel 718 (N07718), Incoloy 800 / 800H / 800HT (N08800 / N08810 / N08811), Incoloy 825 (N08825), Hastelloy C276 (N10276), Hastelloy C22 (N06022), Hastelloy B2 / B3 (N10665 / N10675), Alloy 20 (N08020) |
| Materials — titanium | ASTM B381 Grade F1, F2, F5 (Ti-6Al-4V), F7, F12 |
| Materials — copper-nickel | Cu-Ni 90/10 (UNS C70600) and 70/30 (UNS C71500), ASTM B151 bar; flanges to ASME B16.5 or EEMUA 145 |
| Grade availability | Every grade listed is made or supplied against order, with EN 10204 3.1 certificates (3.2 / third-party inspection when specified) and PMI on alloy, stainless, duplex and nickel grades. |
| Options | Tapped NPT or socket-weld centre hole, lifting lugs on heavy sizes |
| Testing | Visual and dimensional inspection, PMI on alloy and stainless grades, hardness; UT, MPI/DPI as specified |
| Documents | EN 10204 3.1 mill test certificate; 3.2 / third-party inspection when the order specifies; dimensional inspection report; IBR certification when specified |
Applications
- Pipe and header end closures
- Vessel and exchanger nozzle covers
- Hydrotest isolation of piping sections
- Pigging and cleaning access points
- Future tie-in points on process lines
Technical data sheets
Dimensions & weights
FAQ
Blind Flange: common questions
Is a blind flange the same as a spectacle blind?
No. A blind flange bolts onto the end of a flanged pipe. A spectacle blind, spade or spacer to ASME B16.48 is a line blank inserted between two flanges to isolate a line in service.
Can a blind flange be tapped?
Yes. A centre or offset tapping can be machined for a vent, drain, pressure gauge or instrument. State the thread (for example ½″ NPT per ASME B1.20.1) or socket size on the order.
Do B16.47 Series A and Series B blind flanges interchange?
No. Series A and Series B have different outside diameters, bolt circles and bolt counts in the same NPS and class. Confirm the series with the mating flange or the piping class.
What thickness is a blind flange?
The thickness is fixed by the class and NPS in ASME B16.5 or B16.47. See the dimension tables linked on this page; they give flange thickness and weight for each size.
Need a size or grade not listed here?
Our engineering team manufactures against your drawing or datasheet, with dimensional sign-off before dispatch.
Send us your specificationTraceability
From mill heat to your site
- 01
Approved mill material
Received against the mill certificate; heat number registered.
- 02
Forging & machining
Heat number carried through every stage in our Indian works.
- 03
PMI, dimensional & NDT
Every lot inspected to the governing standard; TPI witness on request.
- 04
Stamped & certified dispatch
Hard-stamped pieces with EN 10204 3.1 / 3.2 certificates.
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