ANSI/ASME B16.36 Orifice Flange

What is Orifice Flange?

An orifice flange is a specialized type of flange designed for the installation of an orifice plate within a pipeline. The primary purpose of an orifice flange is to facilitate accurate measurement and control of fluid flow rates in industrial processes. Orifice flanges are commonly used in systems where precise monitoring of flow rates is crucial for process control and efficiency.

Orifice flanges play a crucial role in process industries by providing a reliable and standardized method for flow measurement. Their design and features are tailored to accommodate the specific requirements of orifice plate installations in industrial piping systems.

key characteristics and components of an orifice flange

1. Orifice Plate Installation:

   • The central feature of an orifice flange is its capability to accommodate the installation of an orifice plate. The orifice plate is a thin, flat plate with a centrally located hole (or orifice) that creates a flow restriction. The pressure difference across the orifice is measured to determine the flow rate of the fluid.

2. Flange Design:

   • Orifice flanges have a specific design that allows for the secure placement and sealing of the orifice plate. The flange may have raised faces (RF) or ring-type joint (RTJ) facing, depending on the sealing requirements of the application.

3. Bolt Holes and Bolting:

   • Orifice flanges have bolt holes arranged in a circular pattern to allow for the secure attachment of the flange to a mating flange or other components. Bolting is crucial for maintaining the integrity of the flange and ensuring a leak-tight connection.

4. Pressure Taps:

   • Orifice flanges often feature pressure taps, which are small openings located upstream and downstream of the orifice plate. These taps allow for the connection of pressure measurement devices to accurately determine the pressure drop across the orifice.

5. Facing Types:

   • Orifice flanges are available with different facing types, including Raised Face (RF) and Ring Type Joint (RTJ). The facing type is selected based on the specific sealing requirements of the application.

6. Material Options:

   • Orifice flanges can be manufactured from various materials, including carbon steel, stainless steel, alloy steel, and other materials suitable for the operating conditions and fluid being handled.

7. Applications:

   • Orifice flanges find applications in industries such as oil and gas, petrochemical, chemical processing, and other sectors where accurate flow measurement is critical. They are commonly used in pipelines, refineries, and process plants.

8. Flow Measurement Principle:

   • The orifice plate creates a known flow restriction, leading to a pressure drop across the orifice. By measuring this pressure drop, the flow rate of the fluid can be accurately calculated using established flow equations.

The Three Main Components of A Orifice Flanged Joint Are?

Orifice Flange:

The orifice flange itself is a specialized type of flange designed to accommodate the installation of an orifice plate. It has features such as bolt holes, facing types (Raised Face or Ring Type Joint), and pressure taps. The orifice plate is securely installed within the orifice flange to create a known flow restriction in the pipeline.

Orifice Plate:

The orifice plate is a thin, flat plate with a centrally located hole (orifice) through which fluid flows. The size of the orifice determines the flow restriction and affects the pressure drop across the plate. The pressure difference across the orifice is measured to calculate the flow rate of the fluid accurately.

Gasket and Bolting:

The orifice flange joint relies on gaskets and bolting to ensure a leak-tight connection between the orifice flange and its mating flange or other components in the pipeline. The gasket provides a seal between the flange faces to prevent fluid leakage, while bolts secure the flanges together. The bolting arrangement is critical for maintaining the structural integrity of the joint.