Skip to main content

Minimum required thickness of process pipeline (Engineering calculation)

Pressure Calculation

Calculator:Minimum required thickness of pipeline for service as per ASME B31.3







Results:

Min. Reqired Thickness tm (inch):
12.5% Allowance (inch):
Mini. Required Thicknes (mm):

After getting 12.5% allowance (inch) value again check ASME B36.10 or API 574 piping thickness table and choose thicknes value higher then this value for service.



Calculating the Minimum Required Thickness of Pipelines for Service as per ASME B31.3

Introduction:
In the field of engineering, designing safe and reliable pipelines is of utmost importance. The American Society of Mechanical Engineers (ASME) B31.3 code provides guidelines for the design and construction of process piping systems. One critical aspect is determining the minimum required thickness of pipelines to ensure structural integrity and safety. In this blog post, we will focus on calculating the minimum required thickness of pipelines when the corrosion allowance (T) is less than D/6, where D represents the outside diameter of the pipe.

Understanding ASME B31.3:
ASME B31.3 is a widely recognized code that establishes requirements for the design, materials, fabrication, inspection, and testing of process piping systems. It provides guidelines to ensure the safe operation of piping systems handling various fluids under different operating conditions.

Calculation Methodology:
When T is less than D/6, ASME B31.3 provides specific equations to calculate the minimum required thickness of the pipeline. The formula is as follows:


Where:
- t: Minimum required thickness of the pipe
- P: Design pressure (Psi)
- D: Outside diameter of the pipe (Inch)ASME B36.1
- S: Allowable stress of the material at the design temperature (Psi) Stress factor table (ASME B31.3)
- E: Quality factor Table A1-B (ASME B31.3)
- C: Corrosion allowance factor (C)
- W: Weld joint reduction factor

Weld joint quality factor
                               

Coefficent Y Table 304.1.1
Temperature °C(°F)
Material482(900) & Below510(950)538(1000)566(1050)593(1100)621(1150)649(1200)677(1250) & above
Ferritic steels0.40.50.70.70.70.70.70.7
Austenitic steel0.40.40.40.40.50.70.70.7
Nickel alloys
UNS Nos N06617
& N08810 &N08825		1.40.40.40.40.40.40.50.7
Gray Iron0…………………
Other Ductile metals0.40.40.40.40.40.40.40.4

In the above equation, the numerator represents the primary membrane stress while the denominator represents the primary longitudinal stress. The difference between these two values determines the minimum required thickness.

Practical Application:
To calculate the minimum required thickness of a pipeline, follow these steps:

1. Determine the design pressure (P) based on the operating conditions and system requirements.
2. Determine the outside diameter (D) of the pipe.
3. Determine the allowable stress (S) of the material at the design temperature. This value depends on the material used and can be obtained from material specifications or ASME standards.
4. Determine the quality factor (E) based on the material and construction quality. This factor considers the reliability of the material and fabrication processes.
5. Determine the corrosion allowance (T) based on the expected corrosion rates and material compatibility.
6. Determine the weld joint reduction factor (Y) considering the type of weld joint used in the pipeline.
7. Substitute the values into the formula: 
8. Calculate the minimum required thickness (t) using the above equation.
9. Compare the calculated value with the available pipe thickness options. If the required thickness exceeds the available options, select the next higher available thickness.

Conclusion:
Calculating the minimum required thickness of pipelines is a crucial step in ensuring the safety and reliability of process piping systems. By following the guidelines outlined in ASME B31.3 and using the appropriate formula, engineers can determine the minimum required thickness when the corrosion allowance is less than D/6. It is essential to consider the design pressure, outside diameter, allowable stress, quality factor, corrosion allowance, and weld joint reduction factor in the calculation process. Adhering to these calculations helps ensure the integrity of pipelines and enhances overall system performance and safety.

All see: Maximum Allowable reinforcement Video ASME Sec VIII Div 1

Comments

Post a Comment

Followers

Popular posts from this blog

Welder qualification procedure as per ASME Sec IX

  WELDER QUALIFICATON PROCEDURE (FOR PLATE &PIPING) 1.      Test positions for performance qualification 1.1   Positions (Groove weld) plate & pipe: - An angular deviation of plus or minus 15° From specified horizontal and vertical planes is permitted during welding. Position for qualification as per ASME IX QW-461.3 & QW-461.4 Table. 1 Plate Positions Pipe Positions a)        Vertical Position 3G (Fig.1a) b)        Overhead Positions 6G- (Fig.1b)   b) Overhead Position 4G (Fig.1a)               Fig. 1 Position of test peace for Groove weld (Plate & Pipe). 1.2   Test Positions for Fillet Welds: - An angular deviation of plus or minus 15° from the specified horizontal and vertical planes is permitted during welding. Position for qualification as per ASME QW-461.5 Table.2 Fillet joint Positions         a)   Vertical 3F        b)
Post a Comment
Read more

Lathe machine

                                                       TYPES OF LATHE  Lathes are manufactured in a variety of types and sizes, from very small bench lathes used for precision work to huge lathes used for turning large steel shafts. But the principle of operation and function of all types of lathes is same. The different types of lathes are: 1. Speed lathe ( a ) Wood working ( b ) Spinning ( c ) Centering ( d ) Po1ishing   2. Centre or engine lathe ( a ) Be1t drive ( b ) Individual motor drive ( c ) Gear head lathe   3. Bench lathe   4. Tool room Lathe   5. Capstan and Turret 1athe   6. Special purpose lathe ( a ) Whee1 lathe ( b ) Gap bed lathe ( c ) Dup1icating lathe ( d ) T-lathe   7.Automatic lathe Speed Lathe Speed lathe is simplest of all types of lathes in construction and operation. The important parts of speed lathe are following- (1) Bed (2) Headstock (3) Tailstock, and (4) Tool post mounted on an adjustable slide.   It has no
5 comments
Read more

Ultrasonic Flaw Detection: Unveiling the Power of Sound in Non-Destructive Testing

Introduction: Non-destructive testing (NDT) techniques play a vital role in ensuring the integrity and safety of structures, materials, and components in various industries. Among the array of NDT methods available, ultrasonic flaw detection stands out as a powerful and versatile technique. In this blog, we will explore the fundamentals of ultrasonic flaw detection, its applications, and the benefits it offers in detecting and characterizing defects without causing damage. Join us as we dive into the world of sound waves and their ability to reveal hidden flaws. 1. Understanding Ultrasonic Flaw Detection: 1.1 The Basics of Ultrasonics: We'll introduce the principles of ultrasonics, explaining how sound waves are generated, propagated, and detected. 1.2 Interaction with Materials: We'll explore how ultrasonic waves interact with different materials, including their reflection, transmission, and absorption behaviors. 2. How Ultrasonic Flaw Detection Works: 2.1 Transducers: We'
Post a Comment
Read more

Calculator: Remaining Thickness of Pressure vessel API 510 (Identify remaining thickness is safe/unsafe)

Thickness Calculation Remaining Thickness of Pressure vessel to identify safe for service Design Pressure (psi): Radius (inch): Stress (psi) ASME Sec VIII Div 1: Efficiency 'E': T(nominal) (inch): Metal Loss (inch): Calculate   Remaining Thickness of Pressure vessel API 510  (Identify remaining thickness is safe/unsafe) Introduction: In the field of pressure vessel inspection and maintenance, determining the remaining thickness of the vessel is of utmost importance. This calculation helps assess the structural integrity of the vessel and ensures its safe operation. In this blog post, we will explore the method for calculating the remaining thickness of a pressure vessel as per API 510 standards. Formula for Minimum Thickness (Tmin): The API 510 standard
Post a Comment
Read more

Purging Gas in Gas Tungsten Arc Welding: Enhancing Weld Quality and Integrity

Introduction: In the realm of welding, achieving high-quality welds with excellent integrity is paramount. One crucial technique that aids in this endeavor is the use of purging gas. Purging gas plays a vital role in preventing oxidation and ensuring a clean, controlled environment during welding. In this blog, we will explore the significance of purging gas, its purpose, techniques, and benefits in various welding applications. Join us as we delve into the world of purging gas and its impact on weld quality. Back purging is most important phenomenon in GTAW process because this process is mostly used in Stainless steel. Stainless steel is widely used fabrication of chemical, petrochemical, food etc. plant. All thin section and root welding is performed by GTAW process. GTAW process is also very popular in Aluminum welding. In all large diameter pipe the root pass welding is done by GTAW process where the back purging is mandatory. Purging gas protect the weld metal fro
3 comments
Read more

Energy efficiency in Thermal utilities (Chapter 3: Steam System)

  Energy efficiency in Thermal utilities  (Chapter 3: Steam System) Introduction  Steam has been a popular mode of conveying energy since the industrial revolution. Steam is used for generating power and also used in process industries such as sugar, paper, fertilizer, refineries, petrochemicals, chemical, food, synthetic fiber and textiles. The following characteristics of steam make it so popular and useful to the industry:  ¢ Highest specific heat and latent heat ¢ Highest heat transfer coefficient e Easy to control and distribute Cheap and inert   Properties of Steam  Water can exist in the form of solid, liquid and gas as ice, water and steam respectively. If heat energy is added to water, its temperature rises until a value is reached at which the water can no longer exist as a liquid. We call this the “saturation” point and with any further addition of energy, some of the water will boil off as steam. This evaporation requires relatively large amounts of energy, and whil
Post a Comment
Read more