L
- L
- Ladder (Storage tanks)
- Ladder: BS 5395:1985 Part 3
- Ladder: BS EN ISO 14122:2001+A1:2010 Part 1
- Lamination
- Layers of Protection Analysis
- Leak Test
- Leakage Current
- Legacy system
- Level of Confidence (ASTM E456)
- Lifting Appliances
- Lifting Gear
- Lifting Point
- Linearity (IEC 60050-311)
- Lined Plug Valve
- Lining
- Liquefaction
- Liquid-Filled Seal
- Liquified Petroleum Gas
- Live Part
- Locking Device – Examples: Locking Pin, Travel Stop
- Logic Solver
- Low-frequency Ultrasonic Testing
- Lower Control Limit (ASTM E456)
- Lower Flammable Limit (LFL)
- Lower Warning Limit
- Lubricated Plug Valve