What is piping? Standards and Application of Piping.

A piping in engineering context usually refers to a system of pipes used to convey fluids (liquids and gases) from one location to another. These systems are fundamental in a wide range of applications, including plumbing, HVAC (heating, ventilation, and air conditioning), oil and gas industries, water supply systems, and chemical processing plants. Piping systems include not only the pipes themselves but also various components like fittings, valves, and flanges that control the flow, change the direction, or enable the safe operation of the system under different conditions.

Piping systems have several key features that ensure their functionality, safety, and efficiency in transporting fluids. These features include:

1. Material Composition: Piping can be made from a variety of materials, including metal (such as steel, stainless steel, and copper), plastic (such as PVC, ABS, and polyethylene), and sometimes even concrete or ceramic, depending on the application and the type of fluid being transported.
2. Pipe Fittings: Fittings are essential components that connect pipes together or to other components, allowing for changes in direction, branching off, or changes in pipe size. Examples include elbows, tees, reducers, and couplings.
3. Valves: Valves are installed within piping systems to control the flow of fluid. They can stop the flow, regulate the flow rate, or redirect the fluid. Common types of valves include ball valves, gate valves, check valves, and butterfly valves.
4. Supports and Hangers: Pipes are often supported from below or hung from above to maintain their alignment and prevent sagging or movement due to fluid flow, thermal expansion, or external forces. Supports and hangers must be designed to accommodate movement and loads without causing stress or damage to the piping.
5. Insulation: Insulation may be used on piping to conserve energy by maintaining the temperature of the fluids being transported, to protect personnel by controlling the surface temperature of the pipes, and to prevent condensation or freezing in certain environments.
6. Pressure Ratings: Pipes and components are rated for specific pressure levels, known as the pressure rating, which indicates the maximum pressure the piping system can safely withstand. This is crucial for ensuring the safety and integrity of the system, especially in high-pressure applications.
7. Corrosion Resistance: Depending on the fluid being transported and the environmental conditions, piping systems may need to have corrosion resistance. Materials are selected and sometimes treated or coated to resist corrosion caused by the fluid inside or the environment outside.
8. Thermal Expansion Management: Piping systems must accommodate thermal expansion and contraction, which can be significant in long runs of pipe or in systems exposed to wide temperature variations. This is often managed through the use of expansion loops, bends, and expansion joints.
9. Leak Detection and Sealing: Ensuring the integrity of the piping system involves using proper sealing methods (like gaskets, O-rings, and thread sealants) at joints and connections, as well as implementing leak detection systems in critical or high-risk areas.
10. Codes and Standards Compliance: Piping systems must be designed, installed, and maintained in compliance with various industry standards and building codes to ensure safety, reliability, and efficiency. These standards specify requirements for materials, design, fabrication, assembly, erection, inspection, and testing of piping systems.

Each of these features contributes to the overall functionality and safety of a piping system, making it suitable for its intended application, whether it’s in a residential building, a commercial facility, or an industrial plant.

Pipe dimensions are critical for specifying and using piping in various applications. These dimensions include various parameters that define the size and capacity of the pipe, as well as its compatibility with fittings and other system components. Key dimensions and terms you need to know include:

1. Nominal Pipe Size (NPS): This is a standard designation used to describe the size of the pipe. It is a nominal value that does not always match the exact dimensions of the pipe. For example, NPS 1 inch does not mean the outer diameter (OD) is exactly 1 inch. The NPS is more related to the inside diameter (ID) for pipes larger than 12 inches.
2. Outer Diameter (OD): This is the external diameter of the pipe. It is a critical measurement for aligning pipes with fittings, flanges, and valves. For small pipes (up to 12 inches NPS), the OD is larger than the nominal size.
3. Inside Diameter (ID): This is the internal diameter of the pipe, which determines the flow area. The ID can vary significantly depending on the pipe material and wall thickness, even for pipes with the same NPS.
4. Wall Thickness: The wall thickness of a pipe is designated by the schedule number (SCH), which indirectly specifies the thickness. Common schedules include SCH 40, SCH 80, SCH 160, etc. Higher schedule numbers indicate thicker walls that can handle higher pressures.
5. Pipe Length: Pipes come in standard lengths, with specific options for cutting and threading depending on the material and application. Lengths can vary, with some standard lengths being 20 feet for certain materials and diameters.
6. End Finish: The end finish of a pipe refers to its end preparation for connection to other components. Common end finishes include plain ends (PE), beveled ends for welding (BE), threaded ends (TE), and grooved ends for mechanical couplings.

The combination of these dimensions and characteristics determines the pipe’s compatibility with a system’s requirements, including the fluid it will carry, the pressure it must withstand, and the environmental conditions it will face. When selecting a pipe for a particular application, engineers and designers must consider all these factors to ensure the pipe will perform as required while maintaining safety and efficiency.

Nominal Pipe Size (NPS) is a standard used to designate the size of pipes in terms of a nominal dimension, which is not necessarily indicative of the pipe’s exact dimensions. The NPS system is widely used in the United States and around the world for specifying the diameter of pipes. Here are some key points about NPS:

1. Nominal Dimension: Despite its name, the “size” in NPS does not directly correspond to any specific measurement within the pipe. For pipes with an NPS of 12 inches or smaller, the NPS number roughly corresponds to the pipe’s inner diameter (ID) in inches. However, this is not a strict rule, especially for smaller diameters.
2. Diameter: For NPS 14 inches and larger, the NPS number corresponds to the pipe’s outer diameter (OD) in inches. This can be somewhat confusing because for smaller pipes (NPS 12 and below), the NPS number does not directly relate to the outer diameter.
3. Schedule Number: Alongside NPS, the pipe’s wall thickness is designated by a “schedule” number (such as SCH 40, SCH 80, etc.). This number helps determine the thickness of the pipe wall. Higher schedule numbers indicate thicker walls, which can handle higher pressures.
4. Standardization: NPS is standardized and used as a consistent reference in the industry to ensure compatibility and interoperability between different pipes, fittings, and components. The standards specify the outer diameters, wall thicknesses, and other key dimensions for pipes of different NPS sizes.
5. Application: NPS is used across various industries, including plumbing, oil and gas, water supply, and HVAC systems. It helps in specifying and selecting the appropriate piping for different applications based on flow requirements, pressure ratings, and other factors.
6. Conversion to Metric: In regions using the metric system, pipes are often designated by their nominal diameter in millimeters (DN, for “diamètre nominal” or “nominal diameter”). There is a rough equivalence between NPS and DN sizes, but they are not directly interchangeable.

Understanding NPS is crucial for engineers, plumbers, and professionals in related fields to ensure the correct pipe sizes are used in installations and systems, taking into account the flow rates, pressure requirements, and compatibility with other components.

Diameter Nominal (DN) is a standard metric designation used internationally to size pipes and their components, such as fittings and valves. It is part of the International System of Units (SI) and is widely used outside of the United States, where Nominal Pipe Size (NPS) is more common. Here are some key points about DN:

1. Metric Sizing: DN is measured in millimeters and represents a nominal diameter of a pipe. Unlike NPS, which can have a non-intuitive relationship between the size designation and actual dimensions, DN more closely reflects the physical dimensions of a pipe, particularly its diameter.
2. Based on Dimensions: The DN number roughly corresponds to the inner diameter (ID) of the pipe in millimeters for smaller sizes. However, for larger pipes, the DN designation does not directly correspond to any specific dimension of the pipe, similar to how NPS works for larger sizes in the inch-based system.
3. Global Standardization: DN is part of the ISO (International Organization for Standardization) standards, making it a widely accepted method for specifying pipe sizes internationally. This standardization facilitates global trade and interoperability of piping components.
4. Compatibility with NPS: While DN and NPS are based on different measurement systems (metric vs. imperial), there are rough conversion charts available to translate one system to the other. This is important for industries and projects that source piping components from different regions of the world.
5. Use in Various Applications: DN is used across multiple industries, including water supply, chemical processing, HVAC (heating, ventilation, and air conditioning), and oil and gas. It helps in specifying the right pipes for fluid transport needs, ensuring compatibility and efficiency in system designs.

Understanding DN is crucial for professionals working with piping in international contexts or with metric specifications, ensuring that the correct pipe sizes are selected for the required flow rates, system pressures, and installation standards.

Pipe Schedule refers to the wall thickness of a pipe and is a critical factor in determining a pipe’s pressure rating and its strength. The term “schedule” is followed by a number that indicates the thickness of the pipe wall relative to its diameter. This system helps standardize pipe sizes and wall thicknesses to ensure safety, reliability, and compatibility across various applications and industries.

Key aspects of Pipe Schedule include:

1. Standardization: The pipe schedule system is standardized and widely used in industries such as oil and gas, chemical processing, water supply, and construction. It provides a consistent method for specifying the wall thickness of pipes in a way that is understood across different sectors and regions.
2. Schedule Number: The schedule number (Sch) is a dimensionless number that originally correlated to the nominal wall thickness of a pipe. Common schedule numbers include Sch 40, Sch 80, Sch 160, and Sch XXS (double extra strong). Higher schedule numbers indicate thicker walls.
3. Pressure Rating: The thickness of the pipe wall affects the maximum pressure the pipe can handle. Thicker walls (higher schedule numbers) generally mean the pipe can withstand higher internal pressures, making it suitable for high-pressure applications.
4. Material Impact: The actual pressure rating of a pipe also depends on the material it is made from. Pipes with the same schedule but made from different materials might have different pressure ratings.
5. Applications: The choice of pipe schedule is influenced by factors such as the fluid being transported, the operating pressure and temperature, and the desired safety margin. For example, Sch 40 pipes are commonly used in low to medium pressure applications, while Sch 80 pipes are used in higher pressure situations.
6. Compatibility: Fittings, valves, and other components must be compatible with the pipe schedule to ensure proper fit and maintain the integrity of the piping system.

When specifying or working with piping systems, it’s important to consider both the nominal pipe size (NPS) and the pipe schedule to ensure the selected pipe meets the requirements of the application in terms of flow capacity and pressure rating.

A Piping Isometric Drawing is a detailed orthographic representation of a piping system, which is used in the planning and construction of industrial projects, such as in the petrochemical, refinery, power generation, and manufacturing sectors. Unlike traditional 2D drawings, an isometric drawing represents a three-dimensional layout of the piping system on a two-dimensional surface. Here are some key features and benefits of piping isometric drawings:

1. Three-Dimensional Representation: Isometric drawings provide a three-dimensional view of the piping system, which helps in visualizing the layout more effectively. This is achieved by drawing the system at a 30-degree angle to the horizontal, which allows all three dimensions (length, width, and height) to be represented accurately.
2. Clarity and Detail: These drawings include comprehensive details such as pipe dimensions, sizes, specifications, material types, and connection details. They also show fittings, flanges, valves, and other components, making it easier for engineers and constructors to understand the system’s design.
3. Simplification: Despite their detailed nature, isometric drawings simplify complex piping layouts, making it easier to identify paths, connections, and potential issues. This simplification aids in the fabrication, installation, and maintenance of the piping system.
4. Bill of Materials (BOM): Often, piping isometric drawings are accompanied by a bill of materials that lists all the components, materials, and quantities needed for the system. This is crucial for procurement, inventory management, and cost estimation.
5. Coordination: These drawings are essential for coordinating among various disciplines involved in a project, such as structural, mechanical, and electrical teams, ensuring that the piping system fits within the overall project design without conflicts.
6. Troubleshooting and Maintenance: Isometric drawings are valuable tools for operation and maintenance personnel. They help in identifying specific components and their locations within the system, which is crucial for troubleshooting, repairs, and modifications.
7. Standard Symbols and Notations: Piping isometric drawings use standardized symbols and notations for different types of fittings, valves, and connections. This standardization ensures that the drawings can be understood universally by professionals in the field.

Piping isometric drawings are a critical component of the documentation and planning process in industrial projects, facilitating clear communication, accurate construction, and effective maintenance of piping systems.

Piping and plumbing are terms often used interchangeably, but they refer to distinct aspects of fluid transport within different contexts and scales. Here are the main differences between the two:

Scale and Application

• Piping systems are generally associated with the transportation of fluids (liquids and gases) across a wide range of industrial and commercial applications. This includes oil and gas industries, chemical plants, manufacturing facilities, power plants, and more. Piping systems are designed to handle various pressures, temperatures, and flow rates, often involving complex engineering and design to meet specific industrial standards.
• Plumbing, on the other hand, is typically associated with water supply, waste, and venting systems within residential, commercial, and institutional buildings. Plumbing focuses on the installation and maintenance of systems that provide clean water for drinking, cooking, and cleaning, as well as the removal of wastewater.

Complexity and Components

• Piping systems can be highly complex, involving a variety of pipes, valves, pumps, heat exchangers, and control devices to efficiently transport fluids over long distances, often in challenging environmental conditions or requiring precise control of flow rates, pressures, and temperatures.
• Plumbing systems tend to be less complex, focusing on delivering and draining water. Plumbing involves fixtures like sinks, toilets, and showers, as well as systems for heating water, and requires adherence to building codes and standards to ensure health and safety.

Materials

• Piping systems use a wide range of materials suited to the specific fluids being transported and the operating conditions. Materials can include various grades of steel, stainless steel, copper, plastic, and even advanced composites in some high-tech industries.
• Plumbing systems primarily use materials like copper, PVC (polyvinyl chloride), PEX (cross-linked polyethylene), and ABS (acrylonitrile butadiene styrene) for residential and commercial applications, chosen for durability, ease of installation, and compliance with health and safety standards for potable water systems.

Codes and Standards

• Piping systems must adhere to a broad array of industry-specific standards and codes that govern their design, installation, testing, and maintenance. These standards ensure the safe and efficient operation of piping systems under various conditions and can include standards from organizations like the ASME (American Society of Mechanical Engineers), API (American Petroleum Institute), and ASTM (American Society for Testing and Materials).
• Plumbing systems are regulated by national and local building codes, such as the International Plumbing Code (IPC) or Uniform Plumbing Code (UPC) in the United States. These codes ensure that plumbing installations meet health and safety requirements, promote water conservation, and prevent contamination of water supplies.

In summary, while both piping and plumbing deal with the transport of fluids, they differ significantly in their application, complexity, materials, and the codes and standards that govern their design and installation.

Below is a table that summarizes the key differences between piping and plumbing:

This table provides a high-level comparison, highlighting the distinct roles and characteristics of piping and plumbing in different contexts.

Piping systems, especially in industrial and commercial applications, are subject to a wide range of codes and standards. These ensure the safety, reliability, and efficiency of the piping systems. Here’s an overview of some key codes and standards relevant to piping:

1. ASME (American Society of Mechanical Engineers)

• ASME B31 Series: This series includes codes for pressure piping, with each code segment dedicated to a particular type of piping system, such as:
  • B31.1: Power Piping, for piping systems typically found in electric power generating stations, industrial and institutional plants.
  • B31.3: Process Piping, for chemical, petroleum plants, and refineries.
  • B31.4: Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids.
  • B31.8: Gas Transmission and Distribution Piping Systems.

2. API (American Petroleum Institute)

• API 5L: Specifies requirements for the manufacture of two product specification levels (PSL 1 and PSL 2) of seamless and welded steel pipes for use in pipeline transportation systems in the petroleum and natural gas industries.
• API 6D: Specifies requirements for valves for use in pipeline systems.

3. ASTM International

• ASTM A53: Covers seamless and welded black and hot-dipped galvanized steel pipe in NPS 1/8 to NPS 26.
• ASTM A106: Covers seamless carbon steel pipe for high-temperature service.
• ASTM A234: Pertains to wrought carbon steel and alloy steel fittings of seamless and welded construction.

4. ANSI (American National Standards Institute)

• ANSI B16.5: Covers pipe flanges and flanged fittings.
• ANSI B16.9: Factory-made wrought steel butt-welding fittings.
• ANSI B16.11: Forged fittings, socket-welding, and threaded.

5. ISO (International Organization for Standardization)

• ISO 15649: Petroleum and natural gas industries — Piping.
• ISO 4427: Plastic piping systems for water supply and for drainage and sewerage under pressure.

6. NACE (National Association of Corrosion Engineers)

• NACE MR0175/ISO 15156: Materials for use in H2S-containing environments in oil and gas production.

7. Piping Material Specifications

• In addition to these standards, individual plants or projects may have their own piping material specifications (PMS) that dictate the material grade, dimensions, pressure rating, and other details for pipes, fittings, valves, and other components based on the specific requirements of the project.

Compliance with these codes and standards is crucial for the design, fabrication, installation, inspection, and testing of piping systems to ensure they meet safety and operational requirements.

Piping systems are integral to a wide array of industries and applications, serving essential functions such as the transport of fluids, gases, and occasionally solids suspended in fluids. The design, materials, and construction of piping systems vary significantly depending on their specific application, operational conditions, and the nature of the substances they convey. Here are some key applications of piping:

1. Oil and Gas Industry

• Upstream: Piping systems are used in the extraction process, connecting wells to storage tanks and processing facilities.
• Midstream: Pipelines transport crude oil, natural gas, and refined products over long distances, from production sites to refineries and distribution centers.
• Downstream: In refineries and petrochemical plants, piping systems are crucial for the processing, storage, and distribution of petroleum products and chemicals.

2. Chemical and Process Industries

• Piping systems transport raw materials, intermediates, and finished chemical products within chemical plants. They are designed to handle corrosive substances, high pressures, and temperatures, ensuring safe and efficient chemical reactions and processing.

3. Power Generation

• In power plants, piping systems are used for the conveyance of steam from boilers to turbines, cooling water systems, feedwater systems, and for transporting condensate back to the boiler. Specialized piping systems are also used in nuclear power plants to contain and transport radioactive fluids.

4. Water Supply and Treatment

• Piping is used extensively in the collection, treatment, distribution, and recycling of water. This includes water mains, distribution networks, sewage collection systems, and pipelines for treated water.

5. HVAC (Heating, Ventilation, and Air Conditioning)

• Piping systems in HVAC applications are used to distribute water or steam for heating and chilled water for cooling buildings. Refrigerant piping is also used in cooling systems.

6. Food and Beverage Industry

• Piping systems are used for the transport of ingredients, water, and waste. They must meet strict hygiene and safety standards, often using stainless steel or food-grade materials to prevent contamination.

7. Pharmaceutical and Biotechnology Industries

• These industries require highly sanitary piping systems for the processing and manufacturing of pharmaceuticals and biological products, with strict controls to avoid contamination.

8. Marine and Offshore

• Ships and offshore platforms use piping systems for a variety of purposes, including fuel supply, ballast systems, bilge systems, and cargo handling.

9. Mining and Slurry Transport

• Piping is used in mining operations to transport slurries (mixtures of solid particles and liquids), water for processing, and for dewatering systems.

10. Fire Protection Systems

• Piping systems are essential for fire suppression, consisting of sprinklers, standpipes, and hoses, ensuring that water or fire-retardant materials can be delivered effectively in case of a fire.

Each application demands specific considerations in the design, material selection, and maintenance of piping systems to ensure they perform their intended functions safely and efficiently.

Piping specifications, often referred to as “Piping Specs” or “Piping Material Specifications (PMS),” are detailed documents used in the engineering and construction of piping systems. These specifications ensure that all piping components used in a project meet the required standards for performance, safety, and reliability. Here’s what typically goes into piping specifications:

1. Pipe Sizes and Schedules

• Specifies the nominal pipe size (NPS) and pipe schedule (thickness) for various service conditions, considering the fluid properties, operating pressures, and temperatures.

2. Material Grades

• Details the specific materials to be used for different parts of the piping system, such as carbon steel, stainless steel, alloy materials, or non-metallic materials, depending on the fluid service and environmental conditions.

3. Pipe Fittings

• Describes the types and material specifications for fittings such as elbows, tees, reducers, and caps, ensuring compatibility with the pipes and suitability for the intended service.

4. Flanges and Gaskets

• Specifies the types, material grades, and dimensions of flanges and gaskets, including the facing type (e.g., raised face, flat face, ring-type joint) and the bolt/nut material and grade.

5. Valves

• Details the types (e.g., gate, globe, check, ball, butterfly), materials, pressure ratings, and end connections of valves required for controlling and managing the flow within the piping system.

6. Branch Connections and Olets

• Provides specifications for branch connections, including the types (e.g., welded, threaded, socket-weld) and materials for olets (branch fittings), such as weldolets, sockolets, and threadolets.

7. Specialty Items

• Lists any specialty components unique to the system, such as strainers, steam traps, expansion joints, and hose connections, along with their material specifications and installation requirements.

8. Insulation and Coatings

• Specifies requirements for insulation materials and thicknesses for temperature control or personnel protection, as well as any internal or external coatings needed for corrosion protection.

9. Fabrication and Installation

• Provides guidelines for the fabrication, welding, assembly, and erection of piping systems, including acceptable welding procedures, inspection, and testing requirements.

10. Codes and Standards Compliance

• References the applicable industry standards and codes (such as ASME, ASTM, API, ANSI) that the piping components and installation must comply with.

Piping specifications are essential for ensuring the quality and integrity of piping systems. They serve as a guide for engineers, designers, and contractors in selecting the correct materials and components, facilitating the safe and efficient transport of fluids in various industrial and commercial applications.