Valve Fugitive Emissions Failing LDAR Survey
A valve failing its LDAR (Leak Detection and Repair) survey has detectable volatile organic compound (VOC) or methane emissions above the regulated threshold (typically 500 ppm for EPA Method 21, or 10,000 ppm for the 'leaker' definition). Repair is required within a regulated timeframe.
Symptoms
Root Causes
Standard packing reaching end of sealing life
PTFE braided packing in normal service may fail LDAR Class B (100 ppm) criteria after 1–3 years of service.
Wrong packing grade specified
Standard packing to reduce costs rather than low-emissions packing to ISO 15848 Class A specification installed on LDAR-monitored equipment.
Incorrect installation torque
Gland packing not torqued to the manufacturer's specified value results in insufficient seating stress and early fugitive emission failure.
Stem surface damage
Corrosion or mechanical damage to the stem surface allows emissions to bypass even correctly specified and installed packing.
Safety Precautions
- Full PPE for the process fluid
- For toxic service (benzene, H2S, chlorine): full respiratory protection required for valve opening in LDAR repair context
Tools Required
- Calibrated OVA/FID (EPA Method 21 instrument, annual calibration certificate required)
- Torque wrench (calibrated)
- Packing extraction tool
Supplies Needed
- ISO 15848-1 Class A certified packing system (with certification documentation)
- Anti-extrusion rings
- LDAR documentation forms
Step-by-Step Repair Guide
- 1
Determine the required LDAR class and repair deadline
For EPA Method 21: 'leakers' (above 10,000 ppm) must be repaired within 15 days. Equipment above 500 ppm but below 10,000 ppm: repair within next LDAR monitoring interval or as required by the site's LDAR plan. Record the emission level, date of detection, and valve tag in the LDAR database.
- 2
Attempt gland retightening as first repair step
Tighten the gland follower nuts to the manufacturer's maximum specified torque in two half-turn increments. Re-test with OVA within 24 hours. If the emission has dropped below the threshold, mark as repaired in the LDAR database. If it has not, proceed to repacking.
- 3
Repack with ISO 15848 Class A compliant packing
Rpack the valve with a low-emission packing system qualified to ISO 15848-1 Class A (less than 10 ppm). Standard low-emission packing systems for industrial valves: pure flexible graphite ring sets with anti-extrusion rings (for temperatures above 100 degrees C or fire-safe service); carbon fibre or PTFE with graphite anti-extrusion rings (for lower temperatures); or PTFE V-ring stacks for quarter-turn valves with appropriate sealant loading. Install per the packing manufacturer's installation procedure, which specifies exact ring count, orientation, and gland load.
ISO 15848 Class A packing qualification certificates must be available from the packing supplier. Generic claims of 'low emission' without certification are insufficient for LDAR compliance documentation.
- 4
Re-test and document within the regulatory timeframe
After repacking, re-test with a calibrated OVA or FID within 5 days. Document the re-test result, technician ID, packing type and lot number, and gland torque applied. If the re-test still fails, escalate to valve stem inspection and possible valve replacement before the regulatory repair deadline.
When to Replace Instead of Repair
Replace when: the stem is damaged and cannot hold Class A packing performance, or when the stuffing box bore is corroded oversize making correct packing installation impossible.
Related Products
Key Terms Explained
Unfamiliar with any terms used in this guide? Each links to a full engineering definition.
Full valve glossary (113 terms)Quick Reference
- Difficulty
- Moderate
- Est. Time
- 2–4 hours per valve
- Steps
- 4
- Category
- General
Steps
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