Fugitive emissions — the slow leak of process gas through valve stem packing — have moved from an environmental footnote to a purchasing requirement. LDAR programs, methane regulations in Canada and the EU, and corporate ESG targets now push ISO 15848-1 onto ordinary industrial valve orders.
What ISO 15848-1 Certifies
It is a type test for the valve design: the valve cycles hundreds to thousands of times at temperature while helium or methane leakage through the stem seal is measured. The certificate states three things:
- Tightness class: A (tightest), B, or C — class A generally needs bellows or equivalent high-integrity stem sealing.
- Endurance class: CO1/CO2/CO3 for quarter-turn (number of mechanical cycles), CC1–CC3 for rising stem.
- Temperature class: the tested range.
A typical marking reads: ISO FE AH-CO2-t(-29°C,+200°C) — class A with helium, 1,500 cycles, tested range.
ISO 15848-1 vs API 624 / API 641
API 624 (rising-stem valves with graphite packing) and API 641 (quarter-turn) are the API-world equivalents: fixed 310-cycle methane test, max 100 ppmv. US refinery specs typically call API 624/641; international EPC specs call ISO 15848-1. Many valves carry both.
When to Specify It
- Hydrocarbon gas or volatile organic service in a jurisdiction with LDAR obligations.
- Methane-regulated assets (Canada federal methane rules, EU Methane Regulation).
- Not needed for water, air, steam or fire-water systems.
Frequently Asked Questions
Does a low-E certificate cover every size?
No — type approval covers a size/class family around the tested valve. Ask which range the certificate covers, exactly as with fire-safe certification.
Can packing be retrofitted to meet it?
Low-emission packing sets can improve an installed valve, but the ISO 15848-1 claim belongs to the tested design — a retrofit does not create a certificate.
Which of your product groups can come low-E?
API 607 ball valves, API 600 gates, high-performance butterfly valves and forged steel valves are all available in ISO 15848-1 qualified designs on request.
Facing an emissions spec for the first time? Send it over — we will translate it into orderable line items.
