Valve Standards Guide: Certifications, Testing Requirements & Compliance

In valve projects, certification documents do not always match the products being purchased. A certificate may cover only part of a product range but be presented for the entire series. A test report may simply state “Pass” without recording the test pressure, holding time, or test medium. Sometimes the valve itself performs as expected, yet the nameplate, material certificate, and certification scope do not match, causing the product to fail project acceptance.

These issues are difficult to fix once they surface during bidding, customs clearance, or final delivery. The better approach is to confirm the applicable standards, certification scope, testing requirements, and required shipment documents before placing the order. In this guide, PLUMBERSTAR reviews the certifications, testing requirements, and compliance documents commonly required for different markets and service conditions. We also highlight several common purchasing mistakes to help buyers identify potential risks before procurement begins.

1. Why Valve Standards Matter in Engineering Projects

For international engineering projects, compliance with the required standards is often more important than brand or price. A valve may perform well, but if it does not comply with local regulations or industry requirements, it may fail bidding, project acceptance, or even market entry. Reviewing the applicable standards and certifications during procurement is one of the most effective ways to reduce project risk.

1) Different Industries Follow Different Standards

There is no single certification that applies to every valve application. Each industry has its own requirements.
For example, potable water systems commonly require NSF, WRAS, or ACS certification. Oil and gas projects generally follow API standards. Pressure equipment is designed and evaluated in accordance with ASME or EN standards, while fire protection systems may require UL or FM certification.
Before requesting certificates from a supplier, first identify the application, target market, and industry requirements. Then determine which standards actually apply, instead of asking for “every available certificate.”

2) Having a Certificate Does Not Mean Every Valve Is Certified

Many buyers assume that if a supplier holds CE, API, or NSF certification, every product they manufacture is covered. In reality, most certifications apply only to specific products, sizes, materials, or pressure classes. For example, NSF certification for DN15-DN50 brass ball valves does not automatically cover DN100 valves or stainless steel ball valves.

When reviewing supplier qualifications, don’t stop at confirming that a certificate exists. Check whether the exact valve model you intend to purchase falls within the approved certification scope.

3) Valve Standards Affect Cost, Lead Time, and Market Access

Certification determines more than market access. It also affects manufacturing cost and delivery time. Standard industrial valves may only require routine pressure testing before shipment. Valves built to API standards or supplied with PED, NSF, or similar compliance requirements usually require additional material traceability, specialized testing, third-party assessment, and technical documentation. All of these increase both production cost and lead time.

For export projects, confirming the required standards before production starts is far more economical than trying to obtain additional certification after the valves have already been manufactured. It also helps avoid delays during delivery and project acceptance.

2. Common Valve Certifications and International Standards

Different certifications and standards apply to different countries, industries, and applications. Some are required for market access, some govern valve design and manufacturing, while others focus on material safety and performance.

1) Common Certifications for Potable Water Systems (NSF, WRAS, ACS, cUPC)

These certifications apply to valves and piping components used in municipal water supply, building plumbing, drinking water treatment, and water filtration systems. NSF, WRAS, and ACS primarily evaluate lead content, material leaching, and the effect of wetted materials on drinking water quality. cUPC places greater emphasis on product construction, pressure performance, installation dimensions, and compliance with North American plumbing codes. A comparison is shown below.

ACS Certification

2) Common Design, Manufacturing, and Testing Standards for Industrial Valves (API, ASME, ASTM)

These standards are widely used for industrial valves in oil and gas, petrochemical, and high-temperature, high-pressure power applications. The API-based system is recognized throughout the global oil and gas industry, with each standard serving a specific purpose.

a) API Standards (Performance, Fire Safety, and Testing)

API 598: The most widely used American standard for pressure and leakage testing of industrial valves;
API 6D: Covers pipeline valves, including ball valves, gate valves, plug valves, and check valves used in oil and gas pipeline systems;
API 6FA / API 607: API 607 applies to quarter-turn valves and valves with non-metallic seats, while API 6FA covers fire type testing for valves. Typical testing exposes the valve to flames at approximately 925–1095°C for 30 minutes, followed by leakage evaluation during both the fire exposure and cooling stages. Specific requirements depend on the applicable edition of the standard and the valve type.

API Certification

b) ASME Standards (Dimensions, Flanges, and Pressure-Temperature Ratings)

ASME B16.34: Defines pressure-temperature ratings for flanged, threaded, and welded-end valves;
ASME B16.10: Specifies face-to-face and end-to-end dimensions to ensure interchangeability during pipeline installation.

c) ASTM Standards (Valve Body and Trim Materials)

ASTM material standards define the chemical composition, heat treatment requirements, and mechanical properties of valve bodies and trim components. For example, A105 is used for carbon steel forgings, A216 WCB for carbon steel castings, A182 F304/F316 for stainless steel forgings, A351 CF8/CF8M for stainless steel castings, and A182 F51/F53 for duplex stainless steel forgings.

d) NACE MR0175 / ISO 15156

For carbon steel and certain low-alloy steel components, 22 HRC is a commonly accepted maximum hardness limit under NACE MR0175 / ISO 15156. Stainless steels, duplex stainless steels, and nickel alloys should be evaluated according to the material type, service temperature, H₂S partial pressure, and operating environment.

3) Valve Compliance Requirements for the European Market (CE and PED)

For valves sold into the European Union, CE marking is based primarily on the Pressure Equipment Directive (PED) 2014/68/EU. In general, PED applies to fixed pressure equipment and pressure accessories with a maximum allowable pressure (PS) above 0.5 bar. Some products fall outside the scope of the Directive or are classified under SEP (Sound Engineering Practice).

CE Certificate

a) PED Risk Classification

PED classifies products according to the fluid category, maximum allowable pressure (PS), nominal diameter (DN), and equipment category. Products are generally classified as SEP, Category I, II, III, or IV. Hazardous media, higher pressures, and larger valve sizes usually result in a higher category and require conformity assessment by a Notified Body.

b) Supporting Harmonized Test Standards

Pressure and seat leakage testing is carried out in accordance with EN 12266 and ISO 5208. Chemical plants and VOC control projects in Europe often require additional fugitive emission testing to ISO 15848.

c) Mandatory Compliance Documents

Typical compliance documents include the EU Declaration of Conformity, PED classification records, material traceability documents, pressure test records, and supporting technical documentation. Category II, III, and IV products must also be supplied with the relevant Notified Body certificates or assessment documents required by the selected conformity assessment module. Missing documents, or documents that do not match the supplied product, may result in customs delays, regulatory action, project rejection, or product recall.

4) Certifications for Actuated Valves and Special Service Conditions (UL, FM, ATEX)

These certifications are commonly required for motorized valves, hazardous areas, and fire protection systems.

a) ATEX (Explosion Protection – European Union): ATEX applies to electrical equipment used in hazardous areas within the European Union. Electric actuators must be certified for the appropriate gas or dust explosion group, and ATEX certification is commonly required for valves installed in hazardous locations.

b) UL / FM (North American Electrical Safety and Fire Protection): UL focuses primarily on electrical safety and fire protection equipment, while FM Approvals evaluates products for fire protection and property loss prevention. North American fire protection projects often specify valves that are UL Listed, FM Approved, or both.

c) Other Specialized Certifications: SIL applies to valves and actuators used as final control elements in Safety Instrumented Systems (SIS). ISO 29001 is the quality management standard developed for the oil and gas industry. TSG covers licensing, type testing, and regulatory supervision of special equipment and pressure piping components in China.

3. Common Testing Requirements During Valve Manufacturing

Factory inspection typically covers pressure testing, leakage testing, dimensional inspection, and functional testing. Fire testing, cycle life testing, and fugitive emission testing are performed only when required by the applicable product standard or project specification.

1) Pressure Testing: Verifying Body Strength and Sealing Performance

Pressure testing normally includes a shell test and a seat leakage test. Valves with a backseat design also require backseat testing in accordance with the applicable standard. Shell tests are usually carried out with water or another low-viscosity liquid. Gas testing involves higher risk and should only be used when permitted by the product standard, design documents, or an approved test procedure.

2) Shell Test: Verifying Pressure-Holding Capacity

a) Test pressure: The shell test pressure is typically 1.5 times the valve pressure rating at 38°C;
b) Minimum holding time (Typical minimum requirements under API 598)
DN ≤ 50: 15 s; 50 < DN ≤ 150: 60 s; 150 < DN ≤ 350: 120 s; DN ≥ 350: 300 s;
c) Acceptance criteria: The valve body, bonnet, and flanges shall show no leakage, permanent deformation, or cracks. Test pressure shall remain at or above the value required by the applicable standard throughout the holding period. Some manufacturers also limit pressure fluctuation to within ±5% of the specified test pressure.

3) Seat Leakage Test: Checking Leakage with the Valve Fully Closed

a) High-pressure seat test: The test pressure is typically 1.1 times the valve pressure rating at 38°C;
b) Low-pressure air leakage test: This test is normally carried out with air or an inert gas at 0.4–0.7 MPa. Many factories use 0.6 MPa, although the actual pressure should comply with API 598, the applicable product standard, or the project specification;
c) Leakage classes (ISO 5208)
Class A: No visible leakage is permitted during the specified test period. This class is commonly used for soft-seated valves;
Class D: Commonly applied to certain metal-seated valves. The allowable leakage rate increases with DN. Acceptance limits shall be determined according to the tables in ISO 5208 and converted where required for the selected test medium.

Valve Pressure Testing

4) Material Inspection: Verifying Material Composition and Properties

a) Spectrographic analysis: Depending on the material grade and project requirements, spectrographic analysis or Positive Material Identification (PMI) may be carried out on the valve body, stem, ball, seat, or other critical components to verify that the alloy composition matches both the specified ASTM material grade and the corresponding Material Test Certificate (MTC);

b) Non-Destructive Examination (NDE): UT and RT detect internal defects. MT is used on ferromagnetic materials to identify surface and near-surface flaws, while PT reveals surface-breaking defects on stainless steel and other non-ferromagnetic materials;

c) Material testing for special service conditions:

For H₂S sour service: Verify material hardness, chemical composition, and compliance with the applicable NACE requirements;
For marine or high-salinity environments: Additional salt spray testing, coating thickness measurement, and coating adhesion testing may be required. Where valves are exposed directly to seawater, pitting corrosion, crevice corrosion, and galvanic corrosion should also be evaluated;
For potable water systems: Test lead content, material leaching, and drinking water quality impact in accordance with NSF, WRAS, ACS, or other applicable requirements.

Raw Material Inspection

5) Dimensional Inspection: Ensuring Installation Compatibility

Verify face-to-face dimensions in accordance with ASME B16.10 or GB/T 12224. Check flange dimensions against ASME B16.5 or GB/T 9113. Critical dimensions—including thread depth, flange bolt-hole spacing, face-to-face length, and actuator mounting interfaces—should be fully inspected or sampled according to the inspection plan to prevent installation problems in the field.

Dimensional Inspection

6) Functional Testing: Verifying Valve Operation

Manual valves should be cycled through the full open and closed positions to ensure smooth operation without sticking or binding. Electric and pneumatic valves should complete a full operating cycle while limit switches and feedback signals are checked for proper response. Check valves require a dedicated reverse-pressure closure test.

7) Thread Torque Testing and Cycle Life Testing

Thread torque testing verifies that threaded connections can withstand the specified installation torque without thread stripping, cracking, or permanent deformation. Threaded valves may undergo installation torque testing to confirm the integrity of both the valve body and the threaded connection. Flange bolt tightening torque, stem operating torque, and actuator output torque should also be checked separately.

Cycle life testing evaluates long-term reliability by repeatedly opening and closing the valve. Typical project requirements specify 5,000, 50,000, or 100,000 operating cycles. Manual valves used infrequently are often tested for several thousand cycles. Butterfly valves used in water treatment or automated control systems may require 50,000 cycles, while high-frequency or high-reliability metal-seated ball valves may be specified for 100,000 cycles. Once the test is complete, operating torque and seat leakage should be checked again.

Thread Torque Test

4. What Compliance Documents Should You Request from a Valve Supplier?

Many buyers ask only for CE, API, or ISO 9001 certificates when evaluating a supplier. For engineering projects, that is rarely enough. EPC contractors, government projects, and industries such as oil and gas or chemical processing pay much closer attention to whether a supplier can provide complete, traceable technical documentation. Before placing an order, confirm that the supplier can provide the following documents.

1) Certification Documents

Certification documents demonstrate that a valve complies with the regulations or industry requirements of a specific country, region, or application. Typical examples include NSF, WRAS, ACS, cUPC, CE/PED, API Monogram licenses, and API fire type test reports.
When reviewing certification documents, pay particular attention to the following:

• Whether the certification body is recognized and credible;
• Whether the certificate is still valid;
• Whether the purchased valve model falls within the approved certification scope;
• Whether the size, specification, and material match the product being ordered.

For critical projects, verify the certificate through the official website of the issuing certification body instead of relying solely on the PDF supplied by the manufacturer.

2) Material Certificates

A Material Test Certificate (MTC) shows exactly what materials were used for critical components such as the valve body, stem, and ball. Engineers rely on it to verify that the supplied materials match the project specification, which is why it is one of the most important documents in industrial valve procurement. EN 10204 defines three commonly requested certificate types:

• EN 10204 2.2 Test Report: The manufacturer declares that the product complies with the purchase requirements and provides results from non-specific inspections;
• EN 10204 3.1 Inspection Certificate: An authorized inspection representative, independent of production, issues the certificate and records the actual inspection results for the material batch;
• EN 10204 3.2 Inspection Certificate: The manufacturer’s authorized inspection representative signs the certificate together with the purchaser’s representative or an appointed third-party inspector.

For most international engineering projects, buyers normally request an EN 10204 3.1 certificate. It is widely specified for oil & gas, power generation, and chemical applications.

3) Testing Reports

Testing reports demonstrate that the valve has been tested in accordance with the applicable standard. Typical reports include:

• Shell pressure test;
• Seat leakage test;
• Air leakage test;
• Torque test;
• Functional test;
• PMI report, where required by the project.

A proper testing report should record the applicable test standard, test pressure, holding time, test results, and inspector information. A simple “Pass” statement is not enough. API valves are commonly tested to API 598, while European projects may require EN 12266 or ISO 5208.

4) Inspection Reports

Inspection reports document quality control throughout the manufacturing process and typically include:

• Visual inspection;
• Dimensional inspection;
• Material verification;
• Assembly inspection;
• Final factory inspection.

Large engineering projects may also require an Inspection and Test Plan (ITP), which defines the inspection activities, acceptance criteria, and third-party witness points at each stage of production.

5. Common Mistakes When Purchasing Certified Valves

Based on issues frequently encountered during valve bidding, supplier qualification, and project acceptance, PLUMBERSTAR has summarized the following mistakes buyers should avoid.

Mistake 1: Confusing Quality Management Certification with Product-Specific Certification

Project issue: Many buyers check only the supplier’s ISO 9001 quality management certificate and assume it also proves product compliance. As a result, they overlook product-specific documents such as API fire type test reports, PED conformity documents, TSG licenses, and type test reports;

Risk: ISO 9001 certifies the manufacturer’s quality management system. It does not demonstrate that an individual valve has passed pressure, leakage, fire, or sour service testing. Some traders or manufacturers can obtain ISO 9001 certification at relatively low cost but lack the capability to complete API fire testing or PED third-party conformity assessment. The certificate alone cannot prove that the valve meets project requirements;

Solution: Review supplier qualifications at three levels: ① Factory qualification, including ISO 9001 and ISO 29001; ② Product performance, supported by service-specific type test reports such as API 6FA, PED, and TSG; ③ Documents supplied with each valve, including PMI records, NDE reports, and original pressure test records. All three are essential, and the certificate details must match the DN, pressure class, and material shown on the valve nameplate.

Mistake 2: Assuming One Certificate Covers Every Product While Ignoring PED Classification and API Scope

Project issue: Buyers receive a PED CE certificate or an API 6D report and assume it applies to every valve size, pressure class, and service condition. The same certificate is then used for large, high-pressure valves handling hazardous or toxic media;

Risk: PED classification depends on the equipment type, fluid group, fluid state, maximum allowable pressure (PS), nominal diameter (DN), or vessel volume (V), and divides products into SEP and Categories I to IV. A CE certificate issued for a Category I valve used in water service cannot be used to demonstrate compliance for a Category III or IV valve handling flammable or toxic media. API 6D Monogram licenses and related product documents also define the approved valve type, size range, pressure class, material, and applicable edition of the standard. Products outside that scope are not covered. A common problem is that suppliers provide certificates for small, low-pressure valves while the actual order is for larger valves with higher pressure ratings;

Solution: Check the certification scope as soon as the documents are received. Confirm that the approved DN range, pressure class, fluid group, and risk category match the project requirements. For Category II, III, and IV products, also verify the Notified Body number, conformity assessment module, and supporting certificates.

Mistake 3: Looking Only at the “Pass” Result Without Reviewing the Test Conditions

Project issue: Buyers and inspectors review a pressure test report, see the word “Pass,” and move on. The test pressure, holding time, test medium, and valve specification are never checked;

Risk: Typical problems include insufficient shell test pressure, shortened holding time, or gas being used instead of liquid for shell testing without approval. Under API 598, shell testing is generally carried out at approximately 1.5 times the pressure rating, and large valves may require a minimum holding time of 300 seconds. Without verifying these details, the final result alone has little value;

Solution: Use a standard checklist when reviewing test reports. At a minimum, confirm the test pressure, holding time, test medium, and valve size or pressure class. For high-pressure or high-risk applications, consider sending random samples to an independent laboratory for verification.

Mistake 4: Ignoring the Consistency Between the Valve Nameplate and Certification Documents

Project issue: Suppliers sometimes provide a complete set of certificates and test reports, but the valve nameplate tells a different story. The pressure rating, material, or nominal diameter on the valve does not match the supporting documents. In some cases, one certificate is even used across an entire product range.

Risk: During customs clearance, regulatory inspections, or project acceptance, inspectors check the valve itself first. If the information on the nameplate differs from the certification documents, they can reject the valve as non-compliant, and in some cases the entire shipment may be refused.

Solution: Before accepting the shipment, compare the valve nameplate with every supporting document. Verify the CWP, DN, body material, and manufacturing standard one by one, and make sure they all fall within the certified scope and match the corresponding type test reports. Save clear photographs of the nameplate together with the certification documents for future reference.

Mistake 5: Using General Standards for Special Service Conditions

Project issue: Buyers rely only on general pressure testing standards such as GB/T 13927 without checking whether additional requirements apply to oil and gas, fire-safe service, sour service, hazardous areas, fugitive emissions, or high-temperature power applications. For example, API 6FA or API 607 fire testing may never be confirmed, and project-specific fugitive emission requirements such as ISO 15848, API 624, API 641, or Germany’s TA Luft may be overlooked;

Risk: If the tender documents, regulations, or customer specifications require additional certification or testing, missing documents can lead to bid rejection, failed acceptance, or repeat testing. A valve intended for fire-safe service cannot demonstrate compliance without API 6FA or API 607 test reports. Likewise, valves used in hazardous VOC service in Europe may fail customs clearance or project acceptance if fugitive emission certification is missing;

Solution: Match the required standards to the service conditions before placing the order. Start with the service medium, project location, applicable regulations, product standards, and any additional tests specified by the customer. Oil and gas pipeline projects commonly require API 6D together with API 6FA, NACE, or other standards depending on the operating conditions. European chemical projects generally require PED and may also specify ISO 15848. Projects involving special equipment in China should comply with the applicable TSG requirements.

6. Conclusion

Review valve standards during the quotation stage instead of waiting until production or shipment to collect the required documents. Prepare a project checklist covering the target market, service medium, pressure rating, size range, applicable standards, required testing, and shipment documents, then confirm each item with the supplier before placing the order.

For major projects, include the certification scope, material traceability requirements, inspection witness points, and document submission schedule in the purchase order or technical agreement. Doing so reduces misunderstandings and helps prevent certification or documentation issues from being discovered after production has been completed.

Preparing a valve RFQ or technical specification? Send PLUMBERSTAR the valve type, nominal size, pressure rating, service medium, and target market. We’ll help identify the applicable standards, required testing, and supporting documentation, then recommend valve solutions that fit your project requirements.