D
- D
- Dangerous Substance
- Datum Level
- DCS
- Dead Band (IEC 60050-311)
- Deadband
- Deck
- Declaration of Conformity (Annex VII)
- Defect
- Degradation Mechanism
- Delamination
- Denial of Service (DOS)
- Dependent Failure
- Depression
- Depth of Tread
- Design Authority
- Design Differential Pressure
- Design Fault
- Design Life
- Designer
- Designer (Engineer)
- Deviation (BS EN 60359) / Difference / Error
- Diagnostic
- Differential Settlement
- Dipping Device
- Direct Measurement (BS EN 60359)
- Directional Sound-Pressure
- Directivity Index
- Disable
- Display
- Diver‐less Systems
- Diversity
- Dome Roof
- Dominant Failure Mode
- Double Block and Bleed Valve
- Double Containment
- Double Deck Floating Roof
- Double Isolation Block Valve
- Double Piston Seat Ball Valve
- Double-Sided Weld
- Down Conductors
- Down Time
- Downstream Sealing Valve
- Drain
- Drawings
- Drift (BS EN 61207-1, IEC 60050-311)
- DSEAR
- Duty Holder
- Dynamic restraints – Examples: Snubber, Sway Brace, Shock Arrester
- Glossary