Blind flanges
Solid flanges that close the end of a line, a nozzle or a valve, and allow later extension or inspection access.
About blind flanges
A blind flange (BL) has no bore. Because it carries full pressure across its face, it is the most highly stressed flange type, especially in large sizes.
We also make reducing blinds, blinds drilled and tapped for vents or instruments, and blinds to drawing for test heads and manways.
Where it is used
- Line ends and future tie-ins
- Pressure-test closures
- Vessel nozzles and manways
- Instrument and vent connections (tapped)
Need blind flanges? Get a quotation from the manufacturer.
Send size, class, grade and quantity. We usually reply within one working day.
Dimensions by size and class
Pick a size and class. The cross-section, thickness, hub and bolting update on the drawing.
Flange dimension finder
Every ASME B16.5 dimension for weld neck, slip-on, socket weld, threaded, lap joint and blind flanges, Class 150 to 2500. The section redraws to scale as you change type, size and class.
Dimensions per ASME B16.5. The raised face is not included in thickness or hub length. Matching stud bolts come from Teshi Fasteners as a set.
Grades we manufacture
- A105 / A105N
- A350 LF2
- A694 F42–F70
- F11, F22, F91
- F304/304L
- F316/316L
- F321, F347, F310
- F904L
- F44 (254 SMO)
- F51 / F60 duplex
- F53 / F55 super duplex
- Titanium B381 F-1 to F-12
- Inconel 625, Incoloy 825
- Hastelloy C276
- Monel 400
- Alloy 20
- Cu-Ni 90/10, 70/30
Facings, marking, testing and packing
Facings
- Raised face (RF), serrated 125–250 AARH
- Flat face (FF)
- Ring-type joint (RTJ)
- Tongue and groove, male and female
Marking
Hard-stamped or stencilled with Teshi mark, size, class, grade, heat number, bore or schedule and standard, so every piece traces to its certificate.
Testing
- Dimensional and visual inspection
- PMI on alloy grades
- Hardness, impact (LF2), IGC (stainless) on request
- UT of forgings when your QAP calls for it
Packing
Faces protected, rust-preventive coating on carbon steel, packed in wooden cases or on pallets. Seaworthy packing for export orders.
Questions buyers ask
Can blind flanges be drilled and tapped?
Yes. State the tapping size and thread (for example 1 inch NPT, centred) with your enquiry.
Get a quotation from the manufacturer
Send your BOQ, drawing or tender reference. You deal directly with the manufacturer.
- Reply from our estimation team, usually within one working day
- Carbon steel to titanium on one order
- EN 10204 3.1 or 3.2 certificates, third-party inspection welcome
- ISO 9001:2015 certified and IBR approved, since 1971
Drawings and BOQ spreadsheets are easiest by email. Mention your project name.