What is the difference between the flange of an orifice plate flowmeter and a normal necked flange?

Project Overview

　　Orifice plate flowmeter flanges are specially designed for installing orifice plates for accurate measurement of fluid flow; ordinary necked flanges are used for connecting pipeline equipment to ensure sealing and structural strength. Both are used for pipeline connection, but the design purpose and use of different occasions.

　　Design purpose:

　　1. Orifice plate flowmeter flange: this flange is specially designed for installing the orifice plate flowmeter. An orifice plate is a device used to measure the flow of a fluid (liquid or gas) by installing a thin plate with a fixed diameter orifice in a pipe. The pressure difference between the two sides of the orifice plate is proportional to the velocity of the fluid flowing through the orifice, allowing the flow rate of the fluid to be calculated. The flange of an orifice plate flowmeter usually contains connections for mounting pressure sensors that measure the pressure difference generated before and after the orifice plate.

　　2. Ordinary necked flanges: Ordinary necked flanges (also known as welded neck flanges) are mainly used for connecting pipelines, valves, pumps and other equipment to ensure good sealing and structural strength. It has a longer neck which matches the wall thickness of the pipe and can provide better heat distribution during welding, reduce stress concentration and improve the durability of the connection.

　　Use occasions:

　　1.Orifice plate flowmeter flanges are mainly used in applications that require accurate measurement of fluid flow, such as process control in chemical, oil and gas industries.

　　2.Ordinary necked flanges are widely used in various industrial fields for connecting different components in piping systems to ensure the safe operation of the system.

　　Structural features:

　　1.In addition to the basic connection function, the flanges of orifice plate flowmeter also need to consider how to easily install and remove the orifice plate, as well as how to accurately install the pressure sensor. Therefore, such flanges may have some special designs, such as reserved threaded holes for installing pressure sensors.

　　2. Ordinary necked flanges are characterised by their neck design, which not only helps to improve the strength of the joint, but also provides a more even heat distribution during the welding process and reduces deformation or damage caused by uneven temperatures.

　　In conclusion, although both types of flanges are used for pipeline connections, the flanges for orifice plate flowmeters give more consideration to the needs of flow measurement, while ordinary necked flanges focus on providing a strong mechanical connection and good sealing performance.