| Code | Description |
| PDT | PRESSURE DIFFERENTIAL TRANSMITTER |
| PSH | PRESSURE SWITCH HIGH |
| PSHH | PRESSURE SWITCH HIGH HIGH |
| PSHL | PRESSURE SWITCH HIGH LOW |
| PSL | PRESSURE SWITCH LOW |
| PSLL | PRESSURE SWITCH LOW LOW |
| PT | PRESSURE TRANSMITTER |
| TDT | TEMPERATURE DIFFERENTIAL TRANSMITTER |
| TS | TEMPERATURE SWITCH |
| TSH | TEMPERATURE SWITCH HIGH |
| TSHH | TEMPERATURE SWITCH HIGH HIGH |
| TSHL | TEMPERATURE SWITCH HIGH LOW |
| TSL | TEMPERATURE SWITCH LOW |
| TSLL | TEMPERATURE SWITCH LOW LOW |
| AT | ANALYSIS TRANSMITTER |
| EC | Control boards (e.g. EMS, LLS, etc.) |
| EJ | Interconnecting panels, Junction boxes |
| EL | Auxiliary Service Panel (ASP), Lighting, Small Power, tracing distribution boards |
| ER | Electrical Power Unit (EPU) |
| ES | Motor Driver panel (e.g. VFD, VSD, Soft-Starter, etc.) |