Fugitive emission test

A hydrotest mainly shows that a valve is mechanically strong and does not have “coarse” leaks. Fugitive emission tests are many orders of magnitude more sensitive. They look for small leaks along the spindle, gaskets, and body joints. It is precisely these small, continuous leaks that determine your VOC/methane footprint, LDAR scores, and permit risks. With FE tests, you prove something that a regular pressure test never reveals.

Good FE behavior lowers your total lifecycle costs: less product loss, fewer “repeat offenders” in LDAR, fewer emergency repairs, less unplanned downtime, and fewer claims from HSE. A valve with demonstrably low emissions can be more expensive to purchase, but often pays for itself because it stays within the allowable leak limits much longer.

With standards like ISO 15848-1, ISO 12101, API 622/624/641, you speak one language with suppliers and end users worldwide. You avoid discussions like “what do you mean by low emission?”, because the standard defines: test gas, pressure, temperature, number of cycles, and maximum leak rate. This makes quotes comparable, prevents misunderstandings in contracts, and simplifies acceptance by different countries and authorities.

Many regulations prescribe “best available techniques” and low emissions, but do not always specify a particular valve standard. With FE-tested valves, you can demonstrate that you have consciously chosen low-emission technology. This makes permit procedures, audits, and environmental annual reports much easier: you can substantiate that your installation setup meets the stricter VOC and methane targets.

In practice, a large portion of existing valves leak more than was expected at installation, for example due to wear or relaxation of packing. By conducting sample FE tests, you discover which types, sizes, or services have the greatest “leak contribution.” This provides a solid basis to invest specifically in retrofit, re-packing, or replacement, rather than having to start everywhere at once.

FE testing makes performance measurable and discussable. Seal suppliers demonstrate with ISO 12101/API 622 tests what their packing or seal can do; valve manufacturers demonstrate with ISO 15848-1/API 624/641 what the complete valve does; end users can set targeted requirements based on this. As a result, the conversation shifts from “feeling and experience” to demonstrable data about emission behavior.

Fugitive emissions are unwanted, often small but continuous leaks of volatile substances (for example VOCs or methane) through components such as valves, flanges, pumps, compressors, safety valves, and threaded connections. So it is not about chimneys or controlled venting, but about diffuse leaks from the process installation itself.

Because they simultaneously affect three things: product loss, safety, and the environment. Many small leaks together result in significant VOC or methane emissions, higher explosion and health risks, and a worse emissions balance in permits, ESG reports, and climate goals. Legislation regarding VOCs and methane is being tightened worldwide, causing these “small” sources to weigh increasingly heavily.

In most installations, these are moving seals and connections, valve stem seals, packings, flange connections, pumps, compressors, safety valves, and open ends. It is precisely the combination of pressure, temperature, movement, and aging here that can cause emissions to slowly increase if not consciously managed.

FE type tests (for example ISO 15848-1, API 622/624/641, ISO 12101) demonstrate in the lab how “low emission” a component or seal is under standardized conditions.

An LDAR program concerns what happens afterwards in operation – periodic measuring in the installation, detecting leaks, repairing, and reporting. Type tests help you design and select better components; LDAR ensures that the entire facility stays within emission requirements in practice.

With only LDAR you can detect and repair leaks, but you do not solve the design problems. If the basic valves, packings, and flanges are not designed for low emissions, you will consistently have many “leakers” and a lot of repair work.

FE-tested components reduce the initial emission and slow down degradation – LDAR then becomes more monitoring and fine-tuning instead of constantly putting out fires.

Type tests show what a component can do, not what valves or seals still do after years of operation or insufficient maintenance. In practice, installation errors, wear, packing relaxation, damaged flanges, and process changes play a major role. Without LDAR, you do not know which valves or flanges in your existing plant have meanwhile shifted outside the limit values.

You can use FE test results to:
• prioritize valve types and packings with proven low emissions in new construction and retrofit,
• select critical lines where you do plan extra LDAR effort,
• substantiate assumptions in emission factors towards the permit issuer,
• weigh investments (for example FE upgrade versus more measurement rounds) in a substantiated way.

In the Netherlands, under the Environmental Law and the Bal (Environmental Activities Decree), you must limit your emissions to air using Best Available Techniques. For installations with relevant VOC leak losses, this practically means: working according to BBT conclusions from the EU-BREFs, following an LDAR-like approach based on the Handbook on diffuse VOC emissions and the Leak losses Measurement Protocol, and documenting in your environmental permit how you implement and monitor this.

Germany has a very explicit and strict regulation for emissions from installations with TA Luft 2021, in which valves, flanges, and other devices are explicitly considered. TA Luft uses ISO 15848-1 for valves as a technical reference.

As a result, TA Luft-compliant or ISO 15848-1-tested valves have become the natural benchmark for many European and international projects, even outside Germany.

The BREFs and the associated BAT conclusions supplement the IED with concrete requirements: mandatory LDAR programs for diffuse VOC, the use of “closed equipment” such as low-emission valves and flanges, and reporting requirements.

Member States translate that into national rules and permit conditions. For end users, this means demonstrating late in the policy that the component selection (ISO 15848, API, ISO 12101) and the LDAR approach logically align with this BAT line.

In these regions, air and climate laws are already highly developed, with sector-specific rules for refining, chemicals, and oil and gas facilities. They require LDAR programs, impose limits for VOC and methane, and explicitly specify measurement methods (such as EN 15446 and EPA Method 21).

This creates a clear playing field where low-emission components and structured LDAR programs are no longer a “nice to have,” but a prerequisite for operating facilities.

The new EU methane regulation and similar rules in the US and Canada primarily focus on methane but use the same building blocks as VOC policies: LDAR, limitation of venting/flaring, and requirements for closed equipment. The infrastructure and expectations around monitoring and reporting thus move to a level that also becomes decisive for VOC-rich sectors.

TA Luft and Bal (Decision activities living environment) mainly impose emission limits and BAT requirements and largely leave the practical implementation to BREFs, permits, and guidelines.

VLAREM II, appendix 4.4.6 goes a step further by describing an explicit measurement and management program for fugitive VOC emissions, including component categories, emission factors, and reporting content. FE-type tests still remain the design and selection side here, VLAREM regulates how an operator must estimate and monitor the actual emissions.

By combining three levels:

• component level, use low-emission valves, flanges, and seals tested according to ISO 15848-1, API 624/641, or ISO 12101,

• installation level, organize a VLAREM-LDAR program with Method-21-like measurements, emission factors, and reporting,

• documentation, record in a file that FE type tests are prescribed to select “technically tight” devices. This demonstrates compliance both with the letter (VLAREM) and the spirit (BAT, emission reduction) of the regulations.

Focus first on lines where three things come together: high environmental impact (toxic, SVHC, high VOC or methane load), high LDAR burden (many leakers, many repairs), and high availability requirements. There, an FE upgrade yields the most benefit in emission reduction, safety, and lower LDAR effort per year.

Choose one “default route” as the backbone, – for example ISO 12101 + ISO 15848-1 for international projects, or API 622/624/641 for strongly API-driven projects, and place legal “layers” per region on top of that (Bal, TA Luft, VLAREM, EPA/CAA). This way you maintain one internal technical language, while externally showing per country how compliance with local regulations is achieved.

There is no separate “fugitive emission law,” but under the Environmental Law and the Activities in the Living Environment Decree (Bal), you must limit VOC emissions using Best Available Techniques. For installations with relevant VOC leak losses, an LDAR program is almost always imposed in permits, based on the “Measurement protocol for leak losses, volatile organic compounds” and the Handbook on diffuse VOC emissions.

In practice, companies work with the “Measurement Protocol for Leak Losses, Volatile Organic Compounds,” which describes the sniffing method (EN 15446-like) and OGI as BAT for leak detection and repair, including threshold values, inspection frequencies, and reporting for permits and environmental annual reports.

Not for every installation, but in sectors such as refining, organic chemical industry, and tank storage, LDAR is often made mandatory in the Environmental Permit based on EU BAT conclusions for diffuse VOC emissions. The Leak Loss Measurement Protocol is then explicitly mentioned as the implementation.

In Germany, the Bundes-Immissionsschutzgesetz (BImSchG) and especially the Technische Anleitung zur Reinhaltung der Luft (TA Luft 2021) are decisive. TA Luft 2021 explicitly refers to ISO 15848-1 for valves as a reference for fugitive emission testing and sets leak limits for, among other things, flange connections.

TA Luft does not require that every individual valve must be tested, but it does stipulate that for shut-off valves the “state of the art” according to ISO 15848-1 is followed. In practice, many German and international chemical companies therefore demand ISO 15848-1 tested or TA-Luft certified valves in their specifications.

The core is the European Industrial Emissions Directive (IED 2010/75/EU). This is elaborated in BAT conclusions and BREF documents, in which techniques such as LDAR, closed equipment (low emission valves, closed flanges) and limits for diffuse VOC emissions are explicitly established. Member States must implement this through permits and national rules (such as Bal, TA Luft).

Yes, for the oil and gas sectors. The EU Methane Regulation requires operators in the energy chain to detect methane leaks, establish LDAR programs, limit venting and flaring, and report on these. Fugitive emissions from valves, flanges, and other components are explicitly a focus within this.

In the US, the Clean Air Act is the basis, elaborated in NSPS/NESHAP regulations per sector. These refer to EPA Method 21 as the standard for VOC leak detection and require a formal LDAR program with periodic screening, repair deadlines, and record-keeping for many categories of facilities.

Method 21 describes how to measure VOC leaks using an FID/PID, including measurement distances, response times, and leak thresholds. This method is embedded in dozens of federal regulations as a mandatory measurement protocol for LDAR programs at valves, flanges, pumps, and pressure relief valves, among others.

Yes, Canada has federal “Regulations Respecting Reduction in the Release of Methane and Certain VOCs (Upstream Oil and Gas Sector)”. These set limits and LDAR obligations for methane and VOCs from upstream facilities, including inspection frequencies and repair deadlines for leaks. Provinces may impose additional requirements.

The laws and regulations (Bal, TA Luft, IED, Clean Air Act, Canadian methane regulations) usually do not prescribe a specific valve standard, but require “best available techniques” and low fugitive/diffuse emissions.

ISO 15848-1, API 622/624/641 and TA-Luft-based tests then serve as the technical evidence that a valve complies with emission requirements.

No. Each country or region has its own air and climate legislation, but the trend is the same: stricter requirements for VOC and methane emissions, mandatory LDAR programs, and emphasis on BBT.

In practice, the technical standards are converging around ISO 15848-1, TA Luft, EPA Method 21, and EN 15446 as recognizable references.

A type test is an assessment of the design of a representative valve from a design family. That valve is subjected to heavy loading, for example with many mechanical cycles and temperature fluctuations, to classify the performance of the design.

A production test is a (sample-based) inspection of series-produced items from the factory under limited, practical conditions. The type test qualifies the design, the production test checks whether the delivered valves continue to meet that level in practice.

LDAR stands for Leak Detection And Repair. It is a structured program to systematically detect, record, and repair leaks of volatile substances (e.g., VOCs, methane) at components such as valves, flanges, and pumps. The goal is to demonstrably reduce emissions, comply with permit requirements, and prevent unnecessary product loss.

Because methane better aligns with practice and environmental requirements. Helium is ideal for measuring very small leak flows with a vacuum leak detector, but it does not resemble the real process gases. Methane is representative of hydrocarbons and corresponds to how measurements are made in the field, for example with FID equipment in LDAR programs that often work in ppmv methane or “total hydrocarbons.”

By also allowing methane as a tracer, test results can be directly linked to limit values and measurement methods from permits, TA Luft, and LDAR. At the same time, helium remains available for very sensitive, quantitative leak flow measurements with a mass spectrometer. The standard allows both options: helium for the highest measurement sensitivity, or methane when practical relevance and regulatory alignment are more important.

Formally: no, not one-to-one. ISO 15848-1 and ISO 12101 explicitly state that there is no intended correlation between:

•             the total helium leak rates (Pa·m³/s or mbar·l/s, measured with vacuum/bagging), and

•             the local methane concentrations in ppmv (sniffing method), and also not between the helium classes (AH/BH/CH) and the methane classes (AM/BM/CM).

In practice, you can only make a physical comparison under strictly identical measurement conditions, – same method, pressure, geometry and both as leak rate in, for example, Pa·m³/s. Even then it remains an approximation, because helium and methane behave differently. For standard or contract assessment, you may not use a simple conversion factor, but must test in the medium and with the measurement method prescribed by the standard.

ISO 15848-1 aims to record an actual leak flow, not just a gas concentration in the air. In the vacuum method, the inside of the valve is under a known overpressure with helium, while the outside is connected to a helium leak detector in vacuum mode. This evacuates all released helium and directly converts the signal into a leak rate (for example Pa·m³/s or mbar·l/s), which is then compared to a calibration leak.

In a sniff test you mainly measure concentration around the leak, strongly influenced by distance, drafts, and turbulence. The vacuum method is much more sensitive, better calibrated, and less dependent on the operator. As a result, leak rates between different laboratories are reproducible and well comparable, exactly what the standard intends.

A leak rate in class AH is so small that it can practically only be reliably measured with the vacuum method.

ISO 12101 is intended for the type testing of stem seals, in a test setup that is representative for valves. The standard provides a classification system and test procedures to compare the performance of different stem seal designs for volatile emissions.

The standard is especially relevant for packing and seal manufacturers, but also for end users and valve manufacturers. They can see in advance which stem seals achieve a certain fugitive emission performance class, before complete valves are tested according to, for example, ISO 15848-1.

The standard distinguishes among others quarter-turn, non-rotating rising stem and rotating rising stem, so that the same stem seal can be assessed under different movement profiles.

The standard covers compressible seals with and without live loading, elastomers, and pressure-activated seals. Thus, ISO 12101 goes significantly beyond just braided graphite packing.

ISO 12101 only qualifies the stem seal in a test fixture, not the complete valve. First, you qualify the seal design, then valves with that seal can be tested according to other standards, for example ISO 15848-1.

The standard describes tightness classes for testing with helium and methane as tracer gas. This allows a seal manufacturer to demonstrate which leakage class corresponds to a specific medium and a particular measurement method.

ISO 12101 introduces endurance classes based on the number of mechanical cycles and the stem displacement. This allows you to qualify stem seals for, for example, isolation valves with few cycles or control valves with very many cycles.

ISO 12101 is an addition when you want to compare different stem seal designs without performing a complete valve test for each design. The results assist in selecting seals for valves that will later be tested according to ISO 15848-1 or API standards.

The standard allows the qualification to be extended to stem diameters from about half to twice the tested diameter. The condition is that design, materials, and tolerances remain the same.

For end users and engineering firms, ISO 12101 is useful for requiring in specifications that stem seals have a certain ISO 12101 performance class. This makes performance requirements unambiguous and quotes more comparable with each other.

ISO 15848-1 is intended for type testing of complete industrial valves. The standard classifies the external leakage of stem seals and body gaskets when used with volatile emissions and hazardous media.

ISO 15848-1 focuses on external leakage through stem seals and body joints. The standard expresses leakage as leak rate or gas concentration of a tracer gas (usually helium or methane) and links this to tightness classes and endurance classes.

The standard applies to isolation and control valves, both multi-turn, linear, and quarter-turn. The condition is that they are designed for use with volatile organic compounds or hazardous gases and liquids.

ISO 15848-1 allows various measurement methods, such as sniffing tests and chamber systems, as long as the equipment is sufficiently sensitive and correctly calibrated. The standard specifies minimum detection limits and measurement distances.

ISO 15848-2 is for production acceptance testing of valves whose design already has a type approval according to ISO 15848-1. It concerns random sampling inspection of production valves for external tightness of stem and body so that a manufacturer can demonstrate that series production meets the required fugitive emission performance.

API 622 is for type-testing of process packing (compressible packing) for valve stems, focused on fugitive emissions. The standard compares different packing systems in a standardized fixture, under methane, pressure, temperature, and mechanical cycles, plus additional corrosion and material tests.

API 624 is for type testing of rising stem valves with flexible graphite packing on their behavior of fugitive emissions, under specified pressure, temperature, and number of cycles. The test is mainly intended for valves in process installations with VOCs and other hazardous media.

API 641 is for type testing of quarter-turn valves (such as ball valve and butterfly valve) for fugitive emissions. Like API 624, the standard uses a standardized profile with methane as the test gas, but specifically focused on 90° rotating valves.

TA-Luft is a German emission regulation that sets limit values for emissions into the air, including strict limits for fugitive emissions from valves, pumps, and flanges. It is not a test standard but a legal requirement; various FE test standards are used to demonstrate compliance with TA-Luft by showing that equipment is sufficiently leak-tight.

Yes. ISO 12101 prescribes that stem seals are tested in a test fixture, but that fixture may be designed by the seal or valve manufacturer themselves, as long as it is representative of an industrial valve and can withstand all prescribed pressure and temperature conditions. This can be a specially designed fixture, but also a (standardized) test valve used as a fixture.

It is important that all relevant geometry and design details of the used fixture or test valve are recorded in the test report. This way valve manufacturers can later reproduce the conditions and performance and apply the tested stem seal in the same way in their own valves.

ISO 12101 is designed as a supplement to ISO 15848-1: manufacturers can demonstrate with ISO 12101 reports that their stem seal performs well under representative conditions, and then use these seals in valves qualified according to ISO 15848-1.

For both. Manufacturers of stem seals can have their sealing systems type-tested and classified; valve manufacturers select from these combinations whose performance is demonstrable. End users benefit because they can request specifications and reports with a recognizable ISO-12101 classification.

In practice, crucial data about stem seals was often missing, such as minimum surface pressure, assembly instructions, and limit values. Existing standards focused either on entire valves (ISO 15848-1, API 624/641) or on packing in a standard fixture (API 622).

ISO 12101 specifically focuses on the stem seal itself, with more realistic geometry and full documentation.

ISO 15848-1 is set up for type tests with pressure, temperature cycles, and mechanical cycles, where external leakage via the stem and body is measured using helium or methane. The standard includes leakage tightness classes (A, B, C) and different endurance classes for the number of operating cycles.

ISO 15848-1 is intended for industrial isolation and control valves, both linear and quarter-turn, used with volatile air pollutants or hazardous media.

ISO 15848-1 describes testing from cryogenic (around −196 °C) to high temperatures (typically up to +400 °C), with corresponding temperature and cycle profiles. This allows valves to be qualified for a wide range of process conditions.

Helium is very suitable as a tracer for very low leak rates, while methane better aligns with practical LDAR programs and VOC emissions. ISO 15848-1 does not provide a normative one-to-one correlation between helium and methane, but defines separate tightness classes for both.

ISO 15848-2 requires that a sample of valves from every production series is tested for fugitive emissions. For end users, this means that they not only have a type certificate, but also a guarantee that series valves meet the agreed emission class.

Just like ISO 15848-1, ISO 15848-2 focuses on external leakage through stem (spindle) sealing and body seals. End connections, vacuum applications, and corrosion or radiation influences are outside the scope.

The standard prescribes that at least one valve per batch, type, pressure class, and nominal size must be randomly chosen. The exact selection of a valve is determined in consultation between the manufacturer and the end user.

API 622 test packing with methane as test gas up to approximately 41.4 barg (600 psig) and cycles between ambient temperature and approximately 260 °C, combined with 1,510 mechanical cycles. This provides a representative picture of packing behavior in typical process valves.

API 622 uses a standardized test setup for all packing types, making the results of different suppliers directly comparable. The standard is therefore primarily a basis for comparison, not an as-manufactured certificate for complete valves.

API 622 covers on/off valves with rising and rotating stem. The fixture simulates the relevant movements and loading of the stem seal.

In addition to the FE test, API 622 also includes corrosion tests (cold and hot) on stem and stem seal combinations, and material tests such as weight loss, density, lubricant content, and leaching of components.

API 624 describes a fixed number of operating cycles under constant pressure and temperature, which simulates a longer-term load than a simple final test. The focus is on stable emission performance throughout the entire test duration.

Many refinery and petrochemical specifications require API-624 type testing for steel gate and globe valves with flexible graphite packing in volatile emission services. This is especially true for critical media such as benzene or other VOCs.

API 641 is especially relevant for process installations in which many quarter-turn valves are used, such as ball and butterfly valves in pipelines, tank farms, and gas and oil installations where VOC emission reduction is a priority.

API 641 uses methane as a test gas, just like API 624, because the standard is closely aligned with VOC emissions from hydrocarbon processes and LDAR programs that also work with methane measurements.

TA-Luft is a legal emission regulation, not a test standard. However, the technical rules do refer to test standards and limits for valves and other components. Manufacturers use, among others, ISO 15848-1, API 624/641, and ISO 12101 to demonstrate compliance with TA-Luft requirements.

TA-Luft applies low permissible concentrations (ppmv range) for VOC leaks at valves, pumps, and flanges. In practice, this means that only high-quality stem and body seals, often with additional FE testing, can meet these limits.

Live-loaded seals (with springs) compensate for relaxation, creep, and thermal cycles. ISO 12101 explicitly describes this category so that their actual advantage in terms of stable leak-tightness under FE conditions can be demonstrated.

Yes. ISO 15848-1 defines external leak measurements both around stem/shaft and body joints. In FE-critical installations, both can contribute to total emissions, which is why they are tested and assessed together.

No. ISO 15848-1 focuses on tightness to the environment (fugitive emissions), while ISO 5208 deals with hydrostatic and seat leak pressure tests.

In a complete qualification program, both standards are applied alongside each other.

For valve manufacturers who want to demonstrate serial quality in addition to type certificates, for end users with strict FE requirements in tenders, and for independent test laboratories that carry out production acceptance tests.

API 622 is mainly applied to flexible graphite packing and PTFE/graphite composites, as these are the dominant materials for high-quality FE applications in process valves.

Partially. Both focus on the sealing, not on the complete valve. API 622 works with a fully standardized fixture and test program, while ISO 12101 allows for a custom-made fixture that is closer to the actual valve geometry.

API 624 is more specific (only rising-stem valves, fixed conditions) and is often used as a minimum FE requirement in refinery specifications. ISO 15848-1 is broader in valve types and temperature ranges and offers a more extensive classification system. For high-end applications, both are often combined.

Because the sealing behavior of a 90°-turn ball valve is fundamentally different from that of a rising globe valve. API 641 sets a specific test profile for quarter-turn geometry, while API 624 assumes rising-stem movements.

Yes. In the EU, requirements for VOC emissions are set through BREF documents and national permits. In Belgium, for example, VLAREM plays a role, in the Netherlands the Bal (Environmental Activities Decree), Environmental Act, and permits. TA-Luft is one of the strictest and most explicit references for FE leak limits.

Overhaul companies can purchase stem seals tested according to ISO 12101 and apply them during revision on existing valves, taking into account the compression, surface roughness, and assembly parameters recorded in the test report. This upgrades an old valve to modern FE performance without replacing the body.

Because errors in assembly (incorrect tightening torque, wrong order of rings, poor surface roughness) often have more impact than the material itself. ISO 12101 requires that these parameters be recorded in the report so that the tested performance can be reproduced.

Class AH (strictest helium class at high temperature) is in practice usually only achievable with bellows valves or equivalent shaft seals. For many conventional packing designs, this is an ambitious limit, which also shows how challenging true zero-emission goals are.

Strictly speaking, “zero emission” does not exist, as there will always be a very small amount of leakage or gas diffusion. What we can do, however, is make emissions so small that they remain below the detection limit or under strict regulatory limits.

In certificates and reports, we therefore talk about measured leak values and emission classes, not about truly “zero leakage”.

API 622 contains special “ambient” and “high-temperature” corrosion tests in which packing remains in prolonged contact with metal coupon(s) in an aqueous environment. After completion, pitting and adhesion of corrosion products are evaluated.

Because at higher temperatures oxidation, creep, and relaxation of graphite and PTFE packing increase significantly. By testing up to 538 °C, it becomes clear which packing systems maintain their tightness in high-temperature service.

Legally, ISO 15848-2 is not automatically mandatory, but the permit issuer or end user may require in specifications that valves not only have a type certificate, but are also periodically tested according to ISO 15848-2 as part of quality assurance.

ISO 12101 deliberately focuses on tightness and mechanical/thermal performance. Corrosion falls outside the scope and can be assessed additionally with other standards (or customer-specific tests). This way, the standard remains clear and focused on FE behavior.

The standard was developed in ISO/TC 153 (Valves), with active contributions from ESA (European Sealing Association), FSA (Fluid Sealing Association-USA), and various industry and end-user representatives. As a result, the content aligns with both European and international practice.

The standard prescribes that testing with flammable or inert gases under pressure and at temperature may only be carried out with appropriate safety measures, experienced test personnel, and suitable equipment.

For some large oil and gas companies, API 622 is a strict requirement in purchasing and material specs. For other users, it serves as a best-practice reference for selecting packing. In both cases, an API-622 report provides confidence in the FE performance of the packing.

No. In an installation with mainly rising-stem valves, API 624 is obvious; with a dominant population of ball valves/butterfly valves, API 641 is more logical. In mixed systems, many end users choose a combination of ISO 15848-1 (generic) plus API 624/641 for certain critical lines.

Those who currently only require “TA-Luft-compliant” valves can add an extra layer of specificity with ISO 12101: in addition to a TA-Luft reference, for example, an ISO 12101 class and an API-622 or ISO-15848-1 report are requested. This clarifies which stem-seal has actually been tested and under which conditions.

Through the leakage and durability classes, the standard forces designers to make choices in type of stem system (packing, bellows, cartridge-seal), material combinations, and tolerances. A higher class directly translates to stricter design and cost requirements.

A typical combination is ISO 12101 for qualifying a specific stem-seal design in a representative fixture, plus API 622 as a “baseline” requirement for the graphite packing used. This way you demonstrate both material quality and system behavior.

By providing a single framework worldwide for testing and reporting valve seal performance, it becomes easier for all parties to phase out poor solutions and standardize proven, high-quality seals. This structurally leads to fewer leaks, longer service lives, and lower fugitive emissions.

In principle, that is allowed, but there are clear limitations. An API 622 test fixture is precisely specified in the API 622 standard and is intended for higher temperatures and a linear stem movement (rising stem). The fixture is designed to determine comparative test results of stem seals.

For ISO 12101, the fixture must be representative of the intended application. If you want to test different stem diameters, different temperature ranges, roughnesses, or a different stem (spindle) movement, such as quarter-turn, an API 622 fixture may be unsuitable for that. Always check whether the test fixture can cover all prescribed ISO 12101 conditions (dimensions, movement, and temperatures), otherwise a customized or different fixture is needed.

A Fugitive Emission Test is a leak test that specifically looks at emissions to the atmosphere, meaning the small leaks along stem or spindle seals, gaskets, and body joints, not the internal seat tightness.

The valve or stem seal is subjected to pressure, temperature, and mechanical cycles according to a standard such as ISO 15848-1, ISO 12101, or API 622/624/641, while external leakage is continuously measured using a suitable leak detection method.

FE tests are relevant for three groups – end users/asset owners who want to reduce emissions, safety, and permit risks, valve manufacturers who want to demonstrably deliver low-emission valves, and packing/seal suppliers who want to substantiate the performance of their seals under FE conditions.

Together they use the test results to improve designs, certify products, and refine LDAR strategies.

An FE test at ITIS provides more than just a leak rate; you receive a complete test report with all relevant conditions (standard, medium, pressure, temperature, cycles), a clear assessment against the requested class or limit value, and where applicable, an ISO 17025 test report. Through the ITIS Cloud Portal, you can find test reports and certificates.

The FE test report from ITIS includes, among other things, identification of the test object (type, size, pressure class, serial number), the applied standard(s) and test classes, description of packing/seal and relevant materials, test setup and measuring method, an overview of cycles, pressure and temperature, and the measured leak values per step.

The report indicates whether the measured values are lower or higher than the specified maximum allowable leak rate according to the standard and/or assignment. ITIS does not approve or reject anything itself; we only report the measurement results. Whether the test results are acceptable is up to our client or end user.

Depending on the standard and objective, ITIS uses various test methods, sniff measurements (helium, methane, hydrogen) for stem seals and body joints, vacuum mass spectrometry with helium for very sensitive leak rate measurement, and sometimes chamber systems or bagging.

The valves or stem seals are mounted in representative test setups, with automated operation for cycles and continuous logging of pressure, temperature, and leak rate, so that the full emission behavior over the test is visible.

With ITIS you choose an independent, specialized testing laboratory, possibly operating under ISO 17025 accreditation, with experience in both type testing and customer-specific testing. You benefit from safe test setups, clear reporting in line with the standard text, and the possibility to watch or review tests online.

Due to our experience with end users, valve, stem seal, and gasket manufacturers, we can also contribute to practical test programs that align with real-life situations.

Shell MESC SPE 77/312 is a specification for testing and qualifying valves, which includes pressure tests, functional tests and, depending on the version and project, additional leakage or FE requirements.

For projects where SPE 77/312 is prescribed, ITIS can perform the relevant pressure and leakage tests and, if agreed, combine them with Fugitive Emission tests according to ISO 15848-1 or API standards. This creates a single integrated test program that complies with both Shell specs and FE standards.

Yes. In addition to testing according to ISO 15848-1/-2, ISO 12101, and API 622/624/641, ITIS can also carry out project- or customer-specific protocols. Think of customized pressure and temperature profiles, additional cycles, a combination of seat and FE tests, or specific reporting formats for EPCs and end users.

It is important that the test program is clearly established in advance, specifying which standard or specification serves as the basis, which extra steps are added, and which acceptance criteria apply. This ensures that the results are representative later on for the client, end user, or permit issuer.

In many projects, it is efficient to combine FE tests with other tests, for example: first seat and pressure tests according to ISO 5208 or project specification, then a Fugitive Emission type test according to ISO 15848-1 or an API standard.

ITIS can schedule the test sequence so that tests and cooling or heating cycles are optimally utilized, while the requirements and results of the different standards remain clearly separated and well traceable in the report.