Valve Standards | Industrial Valve Engineering Knowledge Platform

Valve standards form the backbone of safe, reliable, and compliant industrial valve engineering. Whether you’re specifying valves for oil and gas pipelines, chemical processing plants, or power generation facilities, understanding the applicable standards is essential for ensuring performance, safety, and regulatory compliance. This page provides a comprehensive overview of the most widely referenced valve standards — from API and ASME specifications to European directives — helping engineers, procurement professionals, and project managers make informed decisions.

Explore individual standard breakdowns below, including design requirements, testing protocols, material certifications, and real-world application guidance. Use the internal links to dive deeper into each standard or discover how they interconnect across valve selection, materials, and valve types.

Key Valve Standards for Industrial Applications

Industrial valves are subject to rigorous standards developed by organizations such as the American Petroleum Institute (API), the American Society of Mechanical Engineers (ASME), and the European Committee for Standardization (EN). These standards define everything from pressure-temperature ratings and material requirements to testing procedures and dimensional compatibility. Adhering to the correct standards ensures not only equipment reliability and personnel safety, but also alignment with contractual, insurance, and regulatory obligations. Below is a detailed overview of the most critical valve standards used across global industries.

API 6D Explained

API 6D is the internationally recognized standard governing the design, manufacturing, testing, and documentation of pipeline valves — including ball valves, check valves, gate valves, and plug valves used in pipeline and piping systems. Published by the American Petroleum Institute, API 6D establishes requirements for pressure ratings, end connections, materials, marking, and documentation to ensure valves can withstand the demanding conditions of oil and gas transmission pipelines.

For engineers and procurement teams, API 6D compliance is often a mandatory specification in pipeline projects. The standard addresses critical factors such as trunnion-mounted vs. floating ball designs, cavity relief requirements, and stem blowout prevention features. Valves bearing the API 6D monogram have been independently assessed and verified against these requirements, providing a higher level of assurance for long-distance and high-pressure applications.

Related standard: API 598 Testing — Learn how valves manufactured under API 6D are pressure tested and verified for seat leakage and shell integrity.

API 598 Testing

API 598 defines the inspection and test requirements for gate, globe, ball, check, butterfly, and plug valves. It specifies the procedures for shell (hydrostatic), seat (leakage), and backseat tests, including test pressures, acceptable leakage rates, and test durations. This standard is widely referenced across valve datasheets and purchase orders as it provides a common baseline for factory acceptance testing (FAT).

Understanding API 598 is essential for procurement engineers who need to verify that a valve has been properly tested before it leaves the manufacturing facility. The standard categorizes leakage allowances based on valve type and closure element material — distinguishing between metal-seated and soft-seated designs. Knowing these limits helps engineers set realistic acceptance criteria and reduces the risk of valve failures during commissioning or operation.

Related standard: API 6D Explained — Understand how API 598 testing requirements integrate with API 6D pipeline valve specifications.

ASME B16.34

ASME B16.34 is one of the most fundamental standards in industrial valve engineering, covering flanged, threaded, and welding-end valves. It establishes pressure-temperature (P-T) ratings, allowable materials, marking requirements, and design and production testing criteria. The standard applies to a broad range of valve types and is widely referenced in process piping systems governed by ASME B31.3 and B31.1.

The P-T rating tables in ASME B16.34 are particularly important during valve selection, as they define the maximum allowable working pressure for a given material group at specific temperatures. Engineers must verify that the selected valve’s material group and pressure class meet or exceed the process conditions. The standard also specifies minimum wall thickness requirements and design proof testing procedures to ensure structural integrity.

Related standard: API 600 — Explore how API 600 gate valve designs align with ASME B16.34 pressure-temperature ratings and material requirements.

PED 2014/68/EU

The Pressure Equipment Directive (PED) 2014/68/EU is the European Union’s regulatory framework governing the design, manufacture, and conformity assessment of pressure equipment, including industrial valves, intended for use in fluids at pressures exceeding 0.5 bar. Compliance with the PED is mandatory for placing pressure equipment on the EU market and is indicated by the CE marking affixed to qualifying products.

The PED classifies equipment into risk categories (I through IV) based on the type of fluid, pressure, and volume. Valves in higher risk categories require third-party conformity assessment by a Notified Body, while lower-risk categories may allow manufacturer self-certification. For valve manufacturers and end users operating in Europe, understanding the PED is critical not only for market access but also for ensuring that equipment meets stringent safety and design standards. The directive also mandates appropriate material traceability, which connects closely with EN 10204 material certification requirements.

Related standard: EN 10204 3.1 Certification — Discover how EN 10204 3.1 material certificates support PED compliance and CE marking documentation.

EN 10204 3.1 Certification

EN 10204 is the European standard that defines the types of inspection documents provided by manufacturers for metallic products, including the materials used in valve bodies, bonnets, and trim. The most commonly specified document in industrial valve procurement is the 3.1 certificate — a material test report (MTR) issued by the manufacturer’s authorized inspection representative, confirming that the supplied material complies with the specified order requirements.

The distinction between a 2.2 test report (non-specific inspection), a 3.1 certificate (specific inspection by manufacturer’s representative), and a 3.2 certificate (inspection by an independent third party or the purchaser) is critically important for traceability and compliance. In high-integrity applications — such as subsea, cryogenic, or nuclear service — 3.1 or 3.2 certification may be contractually mandatory. Procurement teams should clearly specify the required certificate type in the material requisition to avoid costly documentation rework after delivery.