All you need to know about Transmitter Flange Size and Class

Introduction 

A Transmitter Flange is an external or internal ridge, or rim (lip), items connected with flanges can be assembled and disassembled easily.

There are many different Transmitter Flange standards to be found worldwide. To allow easy functionality and interchangeability, these are designed to have standardized dimensions. Common world standards include

• ASA/ASME (USA)
• PN/DIN (European)
• BS10 (British/Australian)
• JIS/KS (Japanese/Korean)

In the USA, ANSI stopped publishing B16.5 in 1996, and the standard is ASME B16.5

In this article, we mainly talk about ASME and EN-DIN Standard

ASME Standards (U.S.)

ASME (American Society of Mechanical Engineers, of which Australian Pipeline Valve is a member company) is a group of standards, which are in turn covered within the American Standards Institute (ANSI), hence their flanges can be referred to as ANSI or ASME class.

TRANSMITTER FLANGE THAT ARE MADE TO STANDARDS ASME CALLED OUT BY

• ASME5 (the latest version)
• ASME B16.47
• MSS SP-44.

They are typically made from forged materials and have machined surfaces.

TRANSMITTER FLANGE DIMENSION UNDER ASME STANDARD

• ASME B16.5 refers to nominal pipe sizes(NPS) from ½” to 24″.
• ASME B16.47 covers NPSs from 26″ to 60″.

TRANSMITTER FLANGE PRESSURE CLASS UNDER ASME STANDARD

• ASME B16.5 further delineates flanges into seven primary ratings/class: 150 LBS, 300 LBS, 400 LBS, 600 LBS, 900 LBS, 1500 LBS and 2500 LBS.
• ASME B16.47 delineates its flanges into pressure classes 75 LBS, 150 LBS, 300 LBS, 400 LBS, 600 LBS, and 900 LBS.
• A Class 300 flange is rated to a higher pressure than a Class 150 flanges, because a Class 300 flange is constructed with more metal and therefore can withstand more pressure. However there are a number of factors that can impact pressure capability of a flange, obviously temperature is one of them.
• The Pressure Class for flange is often expressed in ‘pounds’. Different names are used to indicate a Pressure Class. For example: 150Lb or 150Lbs or 150#, all mean the same.

TRANSMITTER FLANGE MATERIAL UNDER ASME STANDARD

Materials for flanges are usually under ASME designation including types as below

• SA-105 : Specification for Carbon Steel Forgings for Piping Applications
• SA-266: Specification for Carbon Steel Forgings for Pressure Vessel Components
• SA-182: Specification for Forged or Rolled Alloy-Steel Pipe Flanges, Forged Fittings, and Valves and Parts for High-Temperature Service.

In addition, there are many “industry standard” flanges that in some circumstance may be used on ASME work.

The below two tables are examples of two material groups according to ASTM

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PRESSURE-TEMPERATURE RATINGS OF TRANSMITTER FLANGE

The above seven primary classes do not correspond to maximum pressures in psi. Instead, the maximum pressure depends on both the material of the flange and the temperature.

For example, the maximum pressure for a Class 150 flange is 285 psi, and for a Class 300 Flange it is 740 psi (both are for ASTM A105 Carbon Steel and temperatures below 100F).

The below 2 tables show ANSI/ASME class 150 to 2500LB pressure/temperature ratings for group 2-1.1 and 2-2.3

European Dimensions EN / DIN/ISO7005

WHAT IS DIN

DIN is a type of Standards

When it comes to German flange manufacturing standards, on the other hand, the governing body is the German Institute of Standardization or Deutsches Institut für Normung (DIN).

WHAT IS DN

DN = Diameter Nominal

The term Diameter Nominal refers to the internal diameter of a pipe. The nominal diameter DN is indicated with reference to the corresponding DIN standard. The metric sizes are stated as ‘DN’ (Nominal Diameter) in mm, equivalent imperial sizing is rounded to the nearest multiple of 25mm (for 2” and over) as below.

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WHAT IS PN

PN stands for Pressure Nominal and prefixes the pressure rating. PN is the rating designator follower by a designation number indicating the approximate pressure rating in bars, e.g. a PN16 flange is designed to operate up to 16bar.

• Typical ratings include PN6, PN10, PN16, PN25, PN40, PN64, and PN100.
• The American ANSI standard refers instead to a pressure / temperature rating termed ‘Class’.
• PN ratings do not provide a proportional relationship between different PN numbers, whereas ‘Class’ numbers do.
• Class Ratings based on ASME B16.5 & Corresponding PN Rating:

You can also Click Here to check another post in regards of the details of Transmitter Flange diameter, bolts number, bolts circle diameter etc.

WHAT IS THE RELATIONSHIP AMONG BS,EN,DIN & ISO7005

• British Metric Standard BS4504 is now obsolete and replaced by EN1092-1 edition 09-2008 for steel flanges which also incorporates DIN Standard.
• Flange drillings in EN1092-1 are generally the same as BS4504 and DIN2501 but EN1092-1 covers a wider range.
• Most countries in Europe mainly install flanges according to standard DIN EN 1092-1 (forged Stainless or Steel Flanges).
• ISO 7005 (which AS 4331 is reproduction of) also includes European DIN 2501-1 and BS4504.
• These flanges are the same as EN1092 but EN1092 also includes higher rated DIN based flanges.
• Although the standards say they are identical, there are some very minor flange thickness differences between ISO7005 (AS4331) and EN1092.

TRANSMITTER FLANGE UNDER EN/DIN STANDARD

TRANSMITTER FLANGE MATERIAL UNDER EN/DIN STANDARD

• EN 1092-1 is for stainless or steel flanges
• EN 1092-2 is for iron flanges
• EN 1092-3 is for alloy flanges
• EN 1092-4 is for aluminum alloy flanges