Table of content
Introduction
In the industrial industry, orifice flange is also a commonly used type of flange. Hope it’s not as common as butt welding flanges, flat welding flanges, and blind flange flanges. But it also holds a very important position in industrial systems. What is the difference between orifice flanges and other flanges? What are the main uses? What are its performance and production standards. With these questions in mind, let’s read the following article.
What is an Orifice Flange?
Orifice flange is a relatively special type of flange that usually needs to be used in conjunction with an orifice plate. Its main purpose is to measure flow in pipelines, reduce pressure, or limit flow. This type of flange orifice plate has pressure measuring holes on both sides, which can be used to calculate the flow rate of liquid and gas flowing through the pipeline.
What is an Orifice Flange Used For?
The main purpose of orifice flanges is to calculate flow rates. Generally used in the oil and gas industry, chemical industry. This type of flange is mainly used to calculate flow rate, that is, the volume of fluid flowing through the pipeline.
Common Applications:
- Oil and gas pipeline industry
- chemical plant
- Power generation pipeline system
- water treatment system
What is the Working Principle of an Orifice Flange?
The working principle of an orifice flange is mainly a perforated thin plate installed inside the flange. When the fluid in the pipeline passes through the holes of the orifice plate, a certain pressure drop will be generated. A pressure measuring joint is installed inside the orifice plate flange to measure the pressure before and after the orifice plate. Calculate fluid flow rate through pressure difference.
Simply put: restriction → pressure drop → measurement → flow calculation
What is the Difference Between Orifice Plate and Orifice Flange?
Both have similar names, but their specific uses are not entirely the same.
- Orifice plate: a thin metal plate with drilled holes, used in pipeline systems to restrict flow.
- Orifice flange: It is a combination of orifice plates and flanges that can provide pressure tapping points for measuring flow velocity.
What are the Types of Orifice Flanges?
Orifice flange has different types according to different purposes and designs to adapt to different pipeline applications.
1. Weld Neck Orifice Flange
- Suitable for high-pressure pipeline systems
- Has a fixed function
- There is a long conical hub
2. Slip-On Orifice Flange
- Low price
- Suitable for medium and low pressure pipeline systems
- Easy to use for alignment and installation
3. Threaded Orifice Flange
- Just tighten with the pipeline for installation
- Mostly used for small-diameter pipelines
- Used for medium and low pressure pipeline systems
4. Socket Weld Orifice Flange
- The installation method is to insert the pipeline and then weld it
- Suitable for high-pressure pipeline systems
Orifice Flange Assembly
The composition of an orifice flange includes a flange and an orifice plate. During installation, the orifice plate needs to be placed between two flanges and sealed with a gasket. It is usually equipped with a pressure tap.
Typical parts of an orifice flange assembly include:
- Orifice plate
- Two flanges
- Gaskets
- Bolts & nuts
- Pressure tap connections
Orifice Flange Function
The main functions of orifice flanges are as follows:
- Used to measure the flow rate of liquids or gases in pipelines.
- Plays an important role in pressure measurement and drop.
- You can adjust the traffic.
It is one of the more mainstream measurement methods in industrial pipeline systems.
Orifice Flange Tapping
The unique feature of orifice flanges is tapping holes. It is to drill small holes on the flange for connecting pressure gauges or transmissions, etc.
Common tapping methods:
- Corner Taps: Drill holes directly above the orifice plate.
- Flange Taps: Drill holes on and 1 inch below the orifice plate.
- D&D/2 Taps: Drill holes at one pipe diameter upstream and half pipe diameter downstream of the orifice plate.
Orifice Flange Symbol
In piping and instrumentation diagrams, orifice flanges and orifice plates have their own special symbols. These specifications can help engineering installers quickly identify the location where orifice flanges need to be installed.
This symbol is also frequently used in drawings, and those symbols are: circle with a restriction symbol.
Summary
Although orifice flanges are not commonly heard, they are still very important in pipeline systems. It is mainly used to measure the flow rate of pipelines.
Orifice plates have a good throttling effect.
Orifice flanges can effectively control pressure taps and measure flow values.
There are usually two more common names for orifice flanges and orifice plates:
- Orifice plate = hole maker
- Orifice flange = holder + measurement access
The above is an introduction to orifice flanges, hoping it will be helpful for you to understand this type of flange.
