Understanding valve standards and specifications

Posted by Mark Trainer on Mar 22nd 2024

Hey there, fellow valve enthusiasts! Today, we're looking at valve codes, standards and specifications. Now, I know what you're thinking, this seems like such a 'dry' topic. Believe me, it's anything but!

Valves might seem like simple equipment, but in reality, they've undergone centuries of technological development. Selecting and specifying the right valve for your job lies in understanding valve codes, standards and specifications. This can be a complicated task at times, but fear not! Think of us here at ValveMan as your friendly guide, helping you navigate the maze of acronyms, standards, codes, specifications and all the related technical jargon.

Right, let's begin our journey by unpacking what valve standards, specifications and codes are.

Definition of Valve Codes, Standards and Specifications

What are valve codes, standards and specifications, you ask? Aren't they all the same thing? The simple answer is no, they aren't. This article from Valve World Americas covers the topic rather well.

Codes may be thought of as mandatory design guides or sets of instructions. You'd use codes when dealing with large systems, such as pressure equipment or piping. Codes do not detail everything that goes into the system, these are instead covered by standards. Standards are documents referenced in codes, which contain details regarding design, fabrication, quality control and testing of a particular item. Specifications detail the technical and operational requirements of a specific item, and may be covered in data sheets or supplier documentation.

I know this might sound a bit confusing, so consider the following example:

A processing plant is being built in the United States. Boilers, piping and valves will be needed. Boilers will be designed and built in accordance with the ASME Boiler and Pressure Vessel Code (BPVC). Piping will conform to ASME B31.3 - Process Piping. The ASME B31.3 code references numerous valve standards, for example a standard for ball valves is API Standard 608, Metal Ball Valves—Flanged, Threaded and Welding Ends. For this ball valve, a specification document or data sheet may be prepared prior to ordering the valve. The data sheet will include the valve pressure rating, material combination required, valve end type, valve actuation details and many others.

So, to summarize:

Code: Mandatory design guidelines set by professional bodies and dealing with large systems. Strictly speaking, there aren't any valve codes, although the term is often used when referring to valve standards.
Standard: Guidelines set by professional bodies for quality, safety, and compatibility of components. You'd get standards for valves, flanges and gaskets for example.
Specification: User generated documents detailing equipment size, type, materials, pressure rating, temperature capabilities, etc.

Now that you know what codes, standards and specifications are, let's look at valve standards and specifications in a bit more detail.

Valve Standards

Valve standards are a key aspect of the valve industry that guide design, production, and application of valves. They provide a baseline for safety, reliability, and efficiency by setting minimum guidelines that manufacturers must meet or exceed. Valve standards enable compatibility in regional and global valve use. Instead of each manufacturer creating their own criteria, standards prescribe metrics that promote interoperability, facilitate regulatory compliance, and ensure product quality.

Common Valve Standards Used in Industry

A broad range of valve standards are used across numerous industries. Some of the professional organizations and associations responsible for valve standards include:

American Society of Mechanical Engineers (ASME)
American Petroleum Institute (API)
International Organization for Standardization (ISO)
European Standards Organization (ESO) which produce European Norm (EN) standards

We'll take a closer look at each of these, discuss how they relate to valves, and highlight some of the key valve standards you'll find from each organization.

American Society of Mechanical Engineers (ASME)

ASME is an American professional organization which develops codes and standards related to mechanical engineering and allied fields. ASME is perhaps most famous for their boiler and pressure vessel code (ASME BPVC), which factors heavily into valve design and application. ASME standards focus on the safety, durability, and proper functioning of products within the mechanical engineering realm, including valves. Some common ASME valve standards include:

ASME B16.34: Valves — Flanged, Threaded and Welding End
ASME B16.10: Face-to-Face and End-to-End Dimensions of Valves
ASME B16.24: Cast Copper Alloy Pipe Flanges, Flanged Fittings, and Valves

If you'd like to know more, here's everything you need to know about ASME standards and certifications.

[Image link: https://valveman.com/product_images/uploaded_images/asme-blog-valveman.jpg]

American Petroleum Institute (API)

API, another prominent U.S. organization, represents all sectors of America's oil and natural gas industry. API has developed over 700 standards to enhance safety, efficiency and sustainability within the oil and gas industries. Some common API valve standards include:

API Specification 6D: Specification for Valves
API Standard 607: Fire Test for Quarter-turn Valves and Valves Equipped with Nonmetallic Seats
API Standard 609: Butterfly Valves: Double-flanged, Lug- and Wafer-type, and Butt-welding Ends

International Organization for Standardization (ISO)

ISO is an independent, non-profit international organization that develops standards to ensure the quality, safety, and efficiency of products, services, and systems worldwide. ISO standards offer a harmonized approach to valve design, safety, compatibility and information transfer, which simplifies international valve use and trade. Some common ISO valve standards include:

ISO 6002: Industrial valves — Bolted bonnet steel gate valves
ISO 1721: Flanged steel ball valves
ISO 10631: Metallic butterfly valves for general purpose

European Norm (EN) Standards

EN standards are a comprehensive set of valve standards in Europe, developed by three European standards organizations. These standards ensure compatibility and interoperability of products within the European Economic Area. They play a key role in supporting the single European market for goods and services, including valves and related products. Some common EN valve standards include:

EN 593: Industrial valves - Metallic butterfly valves for general purposes
EN 1349: Industrial process control valves
EN 1983: Industrial valves - Steel ball valves

Understanding valve standards helps to navigate the vast, intricate world of valve specification and application. Valve manufacturers and suppliers are a good reference point regarding the valve standards applicable to your specific application area. For example, valve standards for petrochemical, potable water, pharmaceutical, food and beverage applications would differ significantly.

Valve Specifications

Detailed information needs to be provided to the valve supplier or fabricator when ordering a valve. This ensures that the supplied valve suits the intended use and application. Valve specifications provide a description of a valve's overall design features, functions, and performance standards. They outline characteristics like size, type, materials of construction, end connection type, actuation methods, component pressure rating, valve identification details and many more. The purpose of valve specification is to communicate exactly what type of valve is required, its varying system and environmental operating conditions, and the required compatibility with different applications. For example, you may need valves with steel castings or bolted bonnets. We discuss some of these in the following section.

[Image from Narrato CC Images]

Valve Type

Before deciding on any other specifications, you need to know what valve you are ordering. Broad categories include isolation valves, non-return valves and control valves. There are many different valve types and designs within each category, while certain valves overlap multiple categories. Common valves include ball valves, gate valves, swing check valves and globe valves. A discussion around valve types is a topic of its own. Check out this article for everything you need to know about valve types.

Valve Standard

We've discussed valve standards already in this article. When ordering a valve, you need to indicate the standard the valve should comply with. Consider the scenario where you'd like to order a gate valve. The American Petroleum Institute (API) 602 standard would be suitable if you are specifying a gate valve for petroleum use. However, the American Water Works Association (AWWA) C500 standard would more appropriate if you are selecting a gate valve for a potable water system.

Valve Size and Dimensions

The size and dimensions of a valve are primarily decided based upon expected flow rates and piping details. For example, a control valve and check valve are sensitive to flow rates, hence specifying the correct size is important for effective operation of these valves. Isolation valves such as gate valves are typically used for on-off functionality, so they may be sized to suit the adjoining pipework. Valve sizes are specified in terms of nominal pipe sizes, which are standardized sizes for pipework. Another important dimension worth considering is the valve face-to-face length, which indicates the distance between valve ends. The position and distance to valve flanges, handwheels, levers, gearboxes and actuators are important. It should be easy to access the valve actuator for operations, there should be enough space around the valve for maintenance activities, as well as sufficient headroom for valve removal and installation.

End Connections

Valve end connections serve as the link between a valve and the piping system. The end connection is typically determined by the type of piping system and application — they can range from threaded, flanged and welded to specialty connections. End connections may comply with various standards, and you need to make sure your valve is a match. Specifying an incorrect end connection for your valve means that your valve won't fit the connecting pipework, or will be prone to leakage because of a poor connection.

Pressure Rating

The pressure rating of a valve defines the maximum pressure that a valve can tolerate. It's a critical specification, as exceeding this rating can lead to valve failure and potential system, environmental and personal damage. Pressure rating is linked to temperature capability, for example the stated valve pressure rating is de-rated for high-temperature service. Important parameters outlined under pressure rating include valve hydrostatic strength, operating pressure and test pressure.

Download our free guide if you'd like to know the difference between #150, #300 and #600 pound flanges.

[Image from Narrato CC Images]

Material Selection

Valve material specification plays an important role in both the functionality and longevity of a valve. The choice of material depends on the fluid the valve will be controlling as well as the operating conditions. Materials should be specified for the valve body, disc, seats, seals, stems, shafts, fasteners and other major valve components. Common materials include cast iron, steel, copper alloys, stainless steel and plastics. Exotic materials are also available for demanding applications, however these come at a premium cost. ASTM International, formerly known as American Society for Testing and Materials, commonly provides material specifications.

Actuation Methods

Valves may be operated by various actuation methods. These can be manual (like handwheels or levers), electric, pneumatic, hydraulic, or a combination of these methods. The selected actuation method has a significant influence on valve operation and system control. For more information, check out our practical guide to electric and pneumatic actuators.

Why are Valve Standards and Specifications Important?

Understanding and correctly applying valve industry standards and specifications are key to ensuring smooth operations in various industries, whether you're building hydrogen fueling stations or working on household plumbing. With the correct valve standard and valve spec in place, you can:

Ensure compatibility and interchangeability in valve applications.
Promote safety and reliability in valve operations.
Simplifying valve selection, procurement and installation processes.
Facilitate maintenance and repair activities.
Comply with industry regulations and certifications.

Conclusion

Understanding valve standards and specifications is not only about knowing industry rules — it's about improving functionality, longevity, safety, and ultimately the bottom line. Standards may be mandated by government bodies or developed through consensus by professional associations. Adhering to valve standards can help minimize the risk of plant failures, reduce operational downtime, extend valve life, and improve overall efficiency of a plant or process.

Valve standards and specifications must be continuously developed and refined to cater for emerging technologies. Innovation is rapid, particularly in the area of smart valves, IOT-driven predictive maintenance, additive manufacturing, and highly specialized valve designs tailor-made for specific industry applications. Understanding these developments will help future-proof your operations in a fast-evolving market. The valve industry is a dynamic sector that requires continuous learning and adaptation to stay abreast of the latest developments. Valve suppliers and manufacturers are a great source of reliable, trusted information. So, give ValveMan a shout if you have any valve-related questions.

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Mark Trainer, a Navy Veteran Aviation Electronics Technician and an authority in the valve industry, brings over 40 years of experience in process valves and controls to his role as an Outside Sales Representative for ValveMan.com and FS Welsford Company. His profound knowledge of valve types and control loops, coupled with his ability to provide strategic solutions, has earned him a reputation for reliability and professionalism. Mark's unwavering commitment to customer service and his ability to navigate complex technical challenges consistently result in successful outcomes, driving growth and delivering outstanding results for both companies.