ASME B16.5 | BLRF / BLFF / BLRTJ | Class 150–2500
Blind Flanges are solid flanges without a center bore, designed to close or terminate the end of a piping system, pressure vessel nozzle, valve, or other equipment connection. They provide a reliable pressure boundary and are commonly used for line isolation, pressure testing, inspection, maintenance, and future system expansion.
Elite supplies Blind Flanges in carbon steel, stainless steel, duplex and super duplex stainless steel, alloy steel, low-temperature carbon steel, nickel alloys, and copper-nickel alloys. Products are available in standard ASME dimensions or to customer drawings and project specifications.
| Category | Specification |
|---|---|
| Flange Type | Blind Flange (BLRF / BLFF / BLRTJ) |
| Nominal Size | NPS 1/2–24 per ASME B16.5; larger sizes available to applicable standards |
| Pressure Classes | 150, 300, 400, 600, 900, 1500, 2500 |
| Facing | Raised Face (RF), Flat Face (FF), Ring Type Joint (RTJ), where applicable |
| Primary Dimensional Standard | ASME B16.5 |
| Large-Diameter Flanges | ASME B16.47, where applicable |
| Pipeline Flanges | MSS SP-44, where applicable |
| Manufacturing | Forged / manufactured in accordance with applicable material and dimensional specifications |
| Bore | No center bore; optional special machining or customer-specific configurations available |
| Surface Finish | Standard or customer-specified |
| Heat Treatment | In accordance with applicable material specification |
| Inspection | Visual, dimensional, chemical and mechanical testing as applicable |
| NDE | PMI, UT, MT, PT and other NDE methods as specified |
| Documentation | MTC, EN 10204 3.1/3.2, COC and inspection reports |
| Special Requirements | ITP, third-party inspection, NACE / ISO 15156, sour-service requirements and customer specifications |
For U.S. process and industrial applications, Elite Blind Flanges are primarily supplied in accordance with ASME B16.5.
Applicable standards may include:
For U.S. applications, ASME B16.5 is the primary dimensional and pressure-rating reference for Blind Flanges from NPS 1/2 through NPS 24.
For larger-diameter applications, applicable requirements may be based on ASME B16.47 or project-specific pipeline flange standards.
Carbon Steel
ASTM A105/A105N, ASTM A181, ASTM A350 LF2/LF3 and ASTM A694 F42, F46, F52, F60 and F65.
Stainless Steel
ASTM A182 F304/F304L, F316/F316L, F321/F321H, F347/F347H, F310/F310S, F317 and F904L.
Duplex & Super Duplex
ASTM A182 F51, F53 and F55.
Alloy Steel
ASTM A182 F1, F5, F9, F11, F12, F22, F91 and F92.
Nickel Alloys
Nickel 200/201, Monel 400/K500, Inconel 600/601/625/800/825, Hastelloy C276 and Alloy 20.
Copper-Nickel Alloys
UNS C70600 and C71500, including 90/10 and 70/30 Cu-Ni alloys.
Material selection is based on operating pressure, temperature, process fluid, corrosion conditions, mechanical requirements and applicable project specifications.
Raised Face — RF
The most common configuration for process and industrial piping. The raised sealing surface provides a defined gasket seating area.
Product designation: BLRF — Blind Raised Face Flange
Flat Face — FF
Used where a full-face mating surface is required, including selected equipment and piping applications.
Product designation: BLFF — Blind Flat Face Flange
Ring Type Joint — RTJ
Designed for demanding high-pressure and high-temperature applications using a metallic ring gasket sealing arrangement.
Product designation: BLRTJ — Blind Ring Type Joint Flange
Blind Flanges are manufactured without a center bore and are bolted to a mating flange using the applicable gasket and bolting arrangement.
Typical applications include:
Blind flange thickness and pressure capability are selected according to the applicable flange standard, pressure class, material, temperature and project requirements.
Elite Blind Flanges can be supplied with complete quality documentation, including:
Elite supplies Blind Flanges in a range of configurations, including:
Blind Flanges are commonly used in:
For quotation, please specify:
NPS + Class + Facing + Material + Standard + Quantity + Inspection Requirements
Example:
6″ Class 600 Blind Flange, RF, ASME B16.5, ASTM A105N, MTC
