What Are Flanges?
Per ASME B16.5 and ASME B16.47, flanges are forged or cast steel discs with bolt holes that create a bolted connection between pipes, valves, pumps, and other equipment. They allow piping systems to be assembled, disassembled, and maintained without cutting or welding. At RP Sales, we supply flanges in all standard types and pressure classes from 150# through 2500# per ASME B16.34, covering carbon steel (ASTM A105), stainless steel, and alloy steel grades for every industrial application.
- Weld Neck, Slip-On, Blind, Socket Weld, Threaded, and Lap Joint types
- Pressure classes: 150#, 300#, 600#, 900#, 1500#, 2500#
- NPS 1/2" to 24" (ASME B16.5), NPS 26" to 60" (ASME B16.47)
- Raised Face (RF), Ring Type Joint (RTJ), and Flat Face (FF) finishes
Specifications We Stock
| Size Range | NPS 1/2" to 24" (ASME B16.5), NPS 26" to 60" (ASME B16.47) |
|---|---|
| Pressure Classes | 150#, 300#, 600#, 900#, 1500#, 2500# |
| Material Grades | ASTM A105 (CS), ASTM A182 F304/F316 (SS), ASTM A182 F11/F22/F91 (alloy) |
| Face Types | Raised Face (RF), Ring Type Joint (RTJ), Flat Face (FF) |
| Standards | ASME B16.5, ASME B16.47, ASME B16.36 (orifice), MSS SP-44 |
Common Applications
- Oil & Gas: Pipeline flanged connections, wellhead equipment, manifolds.
- Power Generation: Boiler connections, turbine piping, feedwater systems.
- Chemical & Pharma: Reactor vessels, process piping, clean-room systems.
- Water & Infrastructure: Pump connections, valve assemblies, water treatment plants.
Source Mills We Work With
We procure materials exclusively from highly reputed Indian and global steel mills, including:
Regal Sales CorporationKanak MetalTube Trading Co.Dynamic Forge & Fittings
Applicable Standards & Specifications
How To Order
- Specify flange type (WN, SO, Blind, etc.), NPS size, pressure class, and material grade.
- Indicate face type — Raised Face (RF), Ring Type Joint (RTJ), or Flat Face (FF).
- Provide quantity and delivery location for freight calculation.
- Approve quotation and PO — we dispatch from Kanpur stockyard.
Frequently Asked Questions
What is the difference between weld neck and slip-on flanges?
Weld neck flanges have a tapered hub that is butt-welded to the pipe, providing the strongest and most leak-resistant connection. Slip-on flanges slide over the pipe and are fillet-welded inside and outside. Weld neck flanges are preferred for high-pressure and high-temperature service. Slip-on flanges are cheaper and easier to install for lower-pressure applications.
How do I select the right flange pressure class?
The pressure class (150#, 300#, 600#, etc.) is determined by the system design pressure and temperature. Higher classes have thicker flanges and larger bolts. Your piping engineer's P&ID or line designation table will specify the required class. When in doubt, consult the ASME B16.5 pressure-temperature rating tables.
Do your flanges come with test certificates?
Yes, all flanges are supplied with Mill Test Certificates (MTC) per ASTM A105 or A182 as applicable, stating chemical composition, mechanical properties, and dimensional inspection. For IBR-regulated systems, we can supply flanges with Form III-C documentation.
Related
- Calculate the weight of Flanges for your BOQ — size, wall, and length to MT before requesting a quote.
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