Forged Blind Flanges
A blind flange closes off a pipe or vessel opening. It carries full system pressure across its whole face with no pipe behind it to share the load.
Forged blind flanges close off pipe ends, vessel nozzles and valve openings, carrying full system pressure across an unsupported disc. They are thicker than other flange types for the same class, and supplied to ANSI B16.5 or DIN with EN 10204 3.1 certification.
- Size range
- 15 NB – 600 NB
- Classes
- 150# – 1500#
- Standards
- ANSI B16.5, DIN, IS
- Materials
- A105, F11, F22, F304, F316
- Faces
- RF, FF, RTJ
Forged Blind Flanges at a glance
Quotable facts from Avadh Techno Forge, Gundasara, Gondal, Rajkot.
- Sizes 15 NB to 600 NB
- Classes 150# to 1500#
- Thicker than other flange types
- EN 10204 3.1 certification supplied
Full Pressure Across the Face
Unlike a weld neck flange supported by pipe, a blind flange resists pressure across its entire unsupported disc. Thickness is therefore greater for the same class, and material soundness matters because there is no redundancy behind it.
- Unsupported disc carries full pressure
- Thicker than other flange types
- Fully sound forged material
- Machined sealing face
Sealing Face and Bolt Pattern
The raised face is machined to a controlled serration so the gasket seats properly. Bolt hole pattern and circle must match the mating flange exactly, which is why standards conformance is not optional.
People also ask
What is the difference between a blind flange and a blank flange?
They are the same component under different names — a solid flange with no bore, used to close an opening.
Can a blind flange be drilled later?
It can be machined to add a bore or tapping, but that changes its pressure rating calculation and should be engineered rather than done in the field.
What pressure classes do you manufacture?
150# through 1500# in sizes from 15 NB to 600 NB, in carbon, alloy and stainless grades.
Topics covered on this page
- blind flange
- blank flange
- ANSI B16.5
- pressure class
- raised face
- gasket seating
Based on work carried out at our own forging plant at Gundasara, Gondal, Rajkot — operating since 2008.
Questions Answered
What is a blind flange used for?
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Closing off the end of a pipe, a vessel nozzle or a valve opening, carrying full system pressure across its unsupported face.
Are blind flanges thicker than other flanges?
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Yes, because the disc is unsupported and must resist pressure across its entire area.
Do you supply certification with flanges?
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Yes, EN 10204 3.1 material certificates with heat number traceability and NDT reports where specified.