Important differences between the two codes
- ASME B31. 1 is the code for power piping systems which are those piping systems that are used in the transfer of steam, hot water and other fluids used in the generation of power. Contained here is the scope and codes related to the design, fabrication, and instruction of power piping systems in both nuclear and other industries.
- ASME B31. 3 stands for process piping systems; the process piping systems are the ones used to transport the fluids in industrial or commercial buildings like chemical industries, oil industries, and commercial buildings and the likes. This includes process piping design and fabrication for nuclear and non nuclear facilities, process pipe inspection.
- ASME B31. 1 is more demanding in a way of materials, thickness, and tests, as compared to B31. 3. B31. 1 is more particular on the design and fabrication of the piping systems and has more elaborated procedures for the inspection and testing of power piping systems.
- B31. 3 has more types and sizes of material capability than B31. 1. IGB is also less rigid in design profiles, fabrication and inspection criteria than WITH.
- B31. 1 only relates to the piping systems, B31. 3 also refers to the piping components including the valves, fittings, flanges, gaskets and the likes.
Altogether, both codes are the basic requirements for designing and constructing and inspecting the piping systems. However, ASME B31. 1 deals with power piping systems and offers requirements that are considered more rigid than those given by B31. The third describes process piping systems and offers more flexibility than the first two. They are; firstly, the choice of the right code will depend on the specific project’s characteristics and the type of pipe system that will be deployed.
ASME 31.1 and ASME 31.3
There are so many differences which can be observed after the deep study of two code, however I would like to highlight some differences between the above two code-
B3 1. 3 deals with process piping: namely the piping system commonly applied in petroleum & refineries, chemical & pharmaceutical industries, textile & paper mills, semiconductor & cryogenic plants and terminals, and other related process industries.
Where the factor of safety considered is 3, the thickness is less and hence the involvement of risk is more.
The normal designed life of the plant is approx. 20-25 years.
B3 1. 1 deals with power piping: piping that is usually installed in electric power generating stations, industrial and institutional plants, geothermal heat utilization, central and district heat and power and cold and heat distribution networks.
The number or factor of safety is chosen as 4, hence, thickness is more and, therefore, less risk is incurred. Normal designed life of the plant is about 20-25 years Depending on their capacities & kind of work they have been set up to perform. 40-45 Years. But there is a difference in how the ‘‘stress intensification factor’’ is used in both codes. On the 31st. Thus, the third stress intensification factor is divided into two parts, namely In-plane and out plane stress, while in 31. 1 Both are the same.
Difference between asme 31.1 and 31.3
The ASME B31.1 and B31.3 codes are both piping codes published by the American Society of Mechanical Engineers (ASME). However, they have different scopes and requirements.
- ASME B31. The first of all the power piping codes is code one. They relate to the structural design and material characteristics for the fabrication of the piping systems in power plants, electric power generation stations, industrial and institutional plants, geothermal heating and cooling, central and district heating and cooling systems.
- ASME B31. Of this, one is the Process Piping Code which has the number 3. This include; Designing, making, placing and erecting of pipes that are used for transportation of petroleum and refinery, chemical plant, pharmaceutical plant and many other process industries and the activities involve the inspection and testing of the structures.
Here is a table summarizing the key differences between ASME B31.1 and B31.3:
| Feature | ASME B31.1 | ASME B31.3 |
| Scope | Power piping systems | Process piping systems |
| Requirements | More stringent requirements for pressure design and materials | Less stringent requirements for pressure design and materials |
| Intended use | Power plants, industrial and institutional plants, geothermal heating systems, and central and district heating and cooling systems | Petroleum refineries, chemical plants, pharmaceutical plants, and other process industries |
In general, ASME B31. 1 has higher Pressure Design requirements and Material specification than that of ASME B31. 3. This is so because power piping systems are by normal practice intended to handle higher pressure and temperature in comparison to the process piping system.
ASME B31. 1 which is also used in power plants, industrial and institutional plants, geothermal heating systems and CH/CD plants. ASME B31. 3 is to be utilized in Petroleum refineries, Chemical plants, Pharmaceutical plants and other Industries which are in process.
ASME b31.1 and b31.3 piping standards
The ASME B31.1 and ASME B31.3 are two different piping codes or standards developed by the American Society of Mechanical Engineers (ASME) for the design, construction, inspection, and maintenance of piping systems. Here's an overview of each standard:
ASME B31.1 - Power Piping:
- ASME B31. Power piping codes are represented by 1. It mainly relates to piping systems located in power generation plants, whether they are thermal, nuclear, or hydroelectric.
- This standard addresses the piping systems for all the applications for industries and includes the design, materials, fabrication, assembly, erection, examination, inspection, and testing.
- ASME B31. 1 contains requirements for construction of high-temperature and high-pressure piping systems and their safety.
- It prescribes use of certain material, welding procedures that are to be followed, non-destructive testing and pressure testing.
ASME B31.3 - Process Piping:
- ASME B31. Piping standards have another code which is 3. Some of the application industries of the product include chemical, petrochemical, oil and gas, pharmaceutical and other industries.
- This standard deals with design, materials, fabrication, assembly, erection, examination and or inspection, tests and operations, and maintenance of process piping systems.
- ASME B31. 3 is concentrated at piping systems that convey fluids or gases under normal conditions, or at various temperatures and pressures.
- It gives a very elaborate detail on the required material for construction, calculations on structures, welding procedures, methods of inspection, and pressure test.
In summary, ASME B31. 1 is dedicated to particular power piping systems available in the majority of the power generation stations and ASME B31. 3 is general requirements for process piping systems that are used in various industries. Both are important in as much as they are a guideline when it comes to providing safe, sound and reliable piping systems for their intended use and application in the respective industries. Those involved in engineering and professions that deal with systems should have adequate knowledge of the requirements of the above ASME codes.
ASME b31.3 categories
In ASME B31.3, the categories refer to the various types or classes of fluid service for process piping systems. The categorization helps in specifying the requirements and design considerations for different types of fluids that may flow through the piping system. ASME B31.3 categorizes fluid services into four main categories, which are identified by letters:
Category M:
- Moderate is the meaning of the symbol M in the name of the category Hence, Category M is made up with the fluids that present little threat to life, property, and the wellbeing of the environment.
- Products of this category of fluids are comparatively harmless and could be water, steam, air or other harmless gases or fluids.
- As for the requirements concerning the design and construction, it is for Category M seen as less demanding than for other categories.
Category D:
- Category D is defined as ‘Diverse,’ and it covers all such fluids that may be potentially hazardous, or ones that cause moderate health risks.
- The fluids principally in this category may be any chemicals that may be required in a specific process and may include toxic things or substances.
- Category D piping systems’ design and construction specifications are more demanding than those of Category M because of the risks involved.
Category H:
- Category H literally means ‘Highly Toxic and Hazardous. ’ This category is usually used in describing fluids which are highly toxic, flammable, reactive or are of any other nature that is highly dangerous.
- This is due to the high potential of these fluids to harm the health of persons, the environment, and safety of assets; thus requiring additional measures and planning.
- Flooding systems with Category H fluids require the design, construction and safety features F and G, thus it needs special precautions.
Category A:
- Category A means “High Purity. ” It is applied to such piping systems as they are intended for high-purity service, for example, in chip manufacturing or the production of drugs.
- Products in this category are characterized by requiring extremely clean and free of contaminants.
- Category A piping systems should therefore be very clean and the materials used should also be of high purity.
As for the ASME B31, Series specific booklets, it is pertinent that the current B31 series be recognized as being composed of the following: 3 for the purpose of bringing design and construction requirements especially to the different categories so as not to affect the performance and safety of the piping systems when in contact with different types of fluids. Process piping systems and its designing and construction require engineers and designers to properly classify the fluid service and ensure that they follow the rules and regulations stated in the corresponding category.