A blind flange is the solid disc you bolt on to close the end of a pipe run, the unused nozzle on a vessel, or any spool that you may want to take out for cleaning. RP Sales supplies blind flanges to ASME B16.5 across Class 150 through Class 2500, from 1/2" through 24" NPS, in the four common forged materials (A105 carbon, F304 / F316 stainless, F11 / F22 alloy) and the three common face types (Raised Face, Flat Face, Ring-Type Joint). For Class 150 and 300 in the moving carbon sizes we hold yard stock for next-working-day dispatch; everything above that — higher pressure, larger size, stainless or alloy — is routed mill-direct against the buyer's PO. The freight advantage of ordering through Kanpur instead of a Mumbai stockist matters most for any destination east of Bhopal — which is most of our customer base.
Pressure classes and stocking position
The table below is the working stocking position at our Bartan Bazar yard. Class 150 and 300 in A105 are next-day movers; everything else is on-order against confirmed PO with the typical lead-time band shown.
| Pressure class | Stocking position | Typical lead time |
|---|---|---|
| Class 150 | A105, 1/2" to 12" NPS, RF | Same-day to next-day |
| Class 300 | A105, 1/2" to 12" NPS, RF | Same-day to next-day |
| Class 600 | Selected sizes A105 RF/RTJ | 3-5 working days |
| Class 900 | On order | 3-6 weeks (mill-direct) |
| Class 1500 | On order | 3-6 weeks (mill-direct) |
| Class 2500 | On order | 4-8 weeks (mill-direct) |
Materials — A105 through F22
The forging material set is short. Five grades cover almost every blind-flange specification across utility, process, petrochemical and power applications.
ASTM A105 (carbon steel forging)
General-service forged carbon steel. The default for utility, water, instrument-air and low-temperature hydrocarbon work. Stocked across Class 150 and 300 in the moving sizes.
ASTM A182 F304 / F304L (austenitic stainless)
Corrosion-resistant service — distilleries, food and dairy, ETP and STP work, demineralised-water systems, dilute-acid service. F304L for welded post-assembly to avoid intergranular corrosion in the weld HAZ.
ASTM A182 F316 / F316L (Mo-bearing austenitic stainless)
More aggressive corrosion service — chloride-bearing streams, marine atmospheres, more aggressive process chemistry. The molybdenum addition gives meaningfully better pitting and crevice corrosion resistance than F304.
ASTM A182 F11 (1.25 Cr 0.5 Mo)
Low-alloy for elevated-temperature steam and hydrocarbon piping (typically 425-540°C range). Matches the SA213 T11 tube grade in boiler-side service. Stocked in selected sizes on request.
ASTM A182 F22 (2.25 Cr 1 Mo)
Intermediate alloy for higher-temperature steam (typically 540-580°C range). Matches the SA213 T22 tube grade in superheater and reheater piping. Mill-routed on order.
Face types — RF, FF, RTJ
- Raised Face (RF): the default. Raised seating area for the gasket, with serrations to grip a spiral-wound or non-asbestos gasket. Standard for Class 150 through 600 in most service.
- Flat Face (FF): full-face gasket contact with no raised seating. Used to mate with cast- iron equipment, GRP/FRP flanges and other brittle components that would crack against a raised face.
- Ring-Type Joint (RTJ): machined annular groove that takes a soft-iron or stainless ring gasket. The default for Class 900 and above, and for high- temperature hydrocarbon and refinery service where soft gaskets fail.
Why order blind flanges through our Kanpur yard
The Indian forged-flange industry is concentrated around Mumbai — Bhiwandi, Khopoli, Vasai, Tarapur. The manufacturers do excellent work, but the freight equation from Mumbai to a UP, Bihar, eastern MP or Jharkhand site adds meaningfully to the landed price and to the lead time. A typical road consignment from a Bhiwandi yard to Kanpur runs four to seven working days; to Patna or Ranchi closer to a week.
Ordering through our Kanpur yard pulls the same authorised- manufacturer material through a freight chain that has been optimised for the eastern half of the country since 1994. We coordinate the MTC chain, route the TPI inspection where the buyer wants one, and ship from Kanpur with one-to-two- day delivery into the UP belt and two-to-three days for Bihar and Jharkhand. The arithmetic flips in our favour for any destination east of roughly Bhopal — which is most of our customer base. See the wider Kanpur steel market guide for the freight-geography picture.
What to include in a blind flange enquiry
- Standard: ASME B16.5 (1/2"–24") or B16.47 Series A/B for larger sizes.
- Size: nominal pipe size (NPS / NB) the flange mates to.
- Pressure class: 150 / 300 / 600 / 900 / 1500 / 2500.
- Material grade: A105 / F304 / F316 / F11 / F22 / LCC / F91.
- Face type: RF / FF / RTJ (and surface finish if not standard).
- Quantity and destination PIN code.
- Certification requirement: EN 10204 3.1 standard; 3.2 if TPI required.