ASME B16.47 Large Diameter Flanges (26″ – 60″) Series A & Series B

ASME B16.47 Large Diameter Flanges (26″ – 60″) Series A & Series B –
RAYOUNG Forged Flanges Solutions

We provide high-performance ASME B16.47 large-diameter flanges, both Series A
(MSS SP-44) and Series B (API 605), designed for heavy-duty industrial piping
systems. Covering sizes from 26″ to 60″ and various pressure ratings,
ensuring full compliance with international piping standards and project-
specific requirements.
What Is ASME B16.47?


ASME B16.47 is the standard covering large-diameter steel pipe flanges,
specifically weld neck flanges and blind flanges in sizes 26″ through 60″. It
covers pressure classes 75, 150, 300, 400, 600, and 900, and its materials
align with ASME B16.5 (with the exception of nickel alloys), so the same
pressure-temperature tables generally apply.

The reason B16.47 exists is straightforward: once you get past NPS 24″, the
dimensions in B16.5 simply don’t extend far enough as they weren’t designed
by the committee. Large-diameter piping in pipelines, petrochemical plants,
power generation facilities, and water infrastructure needs its own dimensional
standard, and that’s ASME/ANSI B16.47.

What makes B16.47 different from most other flange standards is that it’s
divided into two categories, Series A and Series B, each with distinct
dimensional requirements, bolt counts, and design philosophies.
Material Grades We Forge
We use premium forged billets to ensure grain flow and structural integrity:

Carbon Steel: ASTM A105, A350 LF2/LF3, A694 F42/F52/F60/F65/F70

Stainless Steel: ASTM A182 F304/304L, F316/316L, F321, F347

Duplex & Alloy: ASTM A182 F51, F53, F55; ASTM A182 F5, F9, F11, F22

ASME B16.47 Series A vs. Series B
Series A (MSS SP-44):
Known as the “heavy-duty” series. Series A flanges are thicker, heavier, and
use larger bolt circles. They are designed to withstand higher external loads
and are the standard choice for new pipeline construction.

Series B (API 605):
Often referred to as the “compact” series. Series B flanges have more but
smaller bolts and a smaller bolt circle. They are lighter and more cost-
effective, typically used for replacements or in space-restricted environments.

Note: Series A and Series B flanges are not interchangeable as their drilling
templates (bolt circles) differ significantly.

Minimum Order: 5 tons

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