How do you design control valves for fugitive emission compliance?

Fugitive emission compliance design: low-emission packing (typically 100 ppmv methane per EPA Method 21), bellows seal backup (zero stem emissions), live-loaded packing (maintains seal force), proper packing material (die-formed graphite), and qualification testing (API 622 or ISO 15848). Documentation: type test certificates, installation specifications, and QA procedures. Monitoring: LDAR (Leak Detection and Repair) program with periodic monitoring, repair triggers, and tracking. Additional measures: gasket selection for body joints, and vacuum service considerations. Lifecycle: proper installation, periodic adjustment, and replacement intervals. Cost-benefit of bellows seal vs enhanced packing depends on application criticality.