Forged Orifice Flanges — Pressure-Tap Flange Pairs per ASME B16.36 for Orifice Plate Differential-Pressure Flow Metering
Shivam Forge manufactures forged orifice flanges — matched flange pairs machined with radial pressure-tap connections either side of an orifice plate to measure differential pressure for custody-transfer and process flow metering — to ASME B16.36 for oil and gas, chemical, and power plant applications. Rajkot, India. Call +91-9265772827.
Orifice plate metering measures flow rate by reading the pressure drop created as fluid accelerates through a precisely sized restriction plate clamped between two flanges, and the accuracy of that measurement depends entirely on tapping pressure at exactly the right locations relative to the orifice plate — too close, too far, or inconsistently positioned pressure taps introduce measurement error that no amount of downstream instrumentation calibration can correct. Orifice flanges solve this by building the pressure tap connections directly into the flange body itself, radially drilled and tapped at standardized distances from the flange face (and therefore from the orifice plate clamped between the flange pair) per ASME B16.36, rather than relying on separately welded pipe taps whose position relative to the orifice plate is harder to control precisely and more prone to installation error. The flange pair is also typically fitted with jack screws, allowing the flanges to be separated just enough to remove, inspect, or replace the orifice plate without fully disassembling the pipe spool — a practical feature that matters considerably in custody-transfer metering runs where plates are periodically inspected or changed to match different flow conditions. Because differential pressure flow calculations are directly sensitive to the precise geometry of the pressure tap locations relative to the orifice bore, orifice flange machining tolerance is genuinely a metrology-grade manufacturing requirement, not just a standard piping fabrication tolerance — a dimensional error at the tap location translates directly into a flow measurement error that can have real commercial consequence in custody-transfer applications.
Forged weld neck orifice flange pairs per ASME B16.36, radially drilled and tapped for pressure connections at standard upstream and downstream distances from the orifice plate location, for permanent flow metering run installations.
Forged flange sets fitted with jack screw bosses allowing the flange pair to be separated enough to remove or replace the orifice plate for inspection or recalibration without fully disassembling the pipe spool.
Forged orifice flanges manufactured to the tighter dimensional and surface finish tolerance custody-transfer fiscal metering applications require, where flow measurement accuracy has direct commercial and contractual consequence.
Forged orifice flanges for internal process flow monitoring applications in chemical, power, and general industrial piping where flow measurement supports process control rather than fiscal custody transfer.
Radial pressure tap hole position, drilled and tapped to ASME B16.36 standard distance from the flange face, held to tight dimensional tolerance since tap location directly affects the accuracy of the differential pressure flow measurement the completed meter run delivers.
Flange bore and gasket face machined to provide correct, even clamping of the orifice plate between the flange pair, ensuring the plate seats flat and perpendicular to flow, which is essential to accurate differential pressure measurement.
Jack screw boss features machined into the flange pair where specified, enabling controlled flange separation for orifice plate access without full pipe spool disassembly during periodic inspection or plate change-out.
Full chemical composition and mechanical property certification per EN 10204 3.1, with 3.2 third-party witnessed certification available for custody-transfer metering and process plant project documentation requirements.
Orifice plate differential pressure metering remains one of the most widely used flow measurement methods across the oil and gas, chemical processing, and power generation industries, precisely because its underlying physics is well understood, well standardized, and produces reliable results when the installation is executed to specification — and the orifice flange is the component that translates that well-understood physics into a repeatable, accurate field installation. The entire measurement principle depends on reading pressure differential at precisely defined locations relative to the orifice plate restriction, which means the flange isn't simply a structural connection holding the plate in place, it is functionally part of the measurement instrument itself.
This is why ASME B16.36 specifies orifice flange pressure tap locations with the same rigor that governs the orifice plate bore sizing and beta ratio calculations that determine the meter run's overall accuracy — a tap positioned even slightly off the standard distance from the flange face introduces a systematic measurement bias that no amount of downstream transmitter calibration can correct, because the error originates in the physical geometry of where pressure is being sampled relative to the flow restriction, not in the instrumentation reading that pressure. For custody-transfer fiscal metering applications, where the flow measurement directly determines a commercial transaction value between a buyer and seller of oil, gas, or other fluid product, this dimensional precision carries real financial consequence rather than being a matter of engineering best practice alone.
The jack screw feature commonly specified on orifice flange pairs reflects a practical operational reality of flow metering: orifice plates are not permanent, set-and-forget components — they may need periodic inspection for erosion or fouling, or replacement with a different bore size if the metered flow rate range changes significantly over the life of the installation, and jack screws allow this without the time and cost of fully disassembling a welded pipe spool. India's expanding natural gas distribution infrastructure and continued oil and gas production and processing capacity have sustained steady domestic demand for correctly manufactured orifice flange meter runs across both custody-transfer and internal process monitoring applications.
For oil and gas, chemical processing, and power plant engineering teams sourcing forged orifice flanges, Shivam Forge manufactures to ASME B16.36 pressure tap location tolerance across carbon, alloy, and stainless steel grades, with jack screw features where specified. Contact our engineering team at +91-9265772827 or sales@shivamforge.com with your meter run drawing and pipe specification for a manufacturability review and quotation.
Differential pressure flow measurement accuracy depends on tapping pressure at precisely standardized distances from the orifice plate, and orifice flanges build these radial pressure tap connections directly into the flange body at ASME B16.36 standard positions. A separately welded pipe tap is harder to position with the same precision relative to the orifice plate and is more prone to installation error that directly translates into flow measurement error.
Jack screws allow the flange pair to be separated just enough to remove, inspect, or replace the orifice plate without fully disassembling the pipe spool — a practical feature for metering runs where the plate is periodically inspected, cleaned, or changed to match different flow rate ranges.
Yes, particularly for the radial pressure tap hole location, bore, and gasket face finish. Because differential pressure flow calculations are directly sensitive to the geometry of the tap locations relative to the orifice bore, dimensional accuracy in these features has a direct, measurable effect on flow measurement accuracy — especially important for custody-transfer fiscal metering applications.
Yes. Custody-transfer metering run orifice flanges can be manufactured to the tighter dimensional and surface finish tolerance fiscal flow measurement applications require, where measurement accuracy has direct commercial and contractual consequence between the transacting parties.
Carbon steel for standard process flow monitoring applications, and alloy or stainless steel grades for higher-pressure, higher-temperature, or corrosive service metering runs — material selection is matched to the pipeline's process specification.
Why Choose Shivam Forge
Shivam Forge delivers precision hot-forged components from our integrated Shapar, Rajkot facility — covering forging, CNC machining, heat treatment, and quality inspection under one roof.
