An equipment and instrumentation numbering system has been developed to facilitate referencing of equipment items. This system is also coordinated with the numbering system used in the Manufacturers’ Operation and Maintenance Manuals, the Contract Documents, and this manual.
A-B-C-D
where:
A = Equipment type (Listed in Table 1-2 below)
B = Unit process number (listed in Table 1-3 below)
C = Loop number (described below)
D = Unit number (only included if there are multiple identical units)
Table 1-2 Equipment Type (A)
| Abbreviation | Equipment Type |
| AE | Analytical element |
| AIT | Analytical indicator and transmitter |
| ARV | Air release valve |
| ATS | Automatic transfer switch |
| B | Blower |
| BFP | Backflow preventer |
| CFS | Chemical feed skid |
| CP | Control panel |
| DPE | Differential pressure element |
| DPIT | Differential pressure indicator and transmitter |
| DS | Door sensor |
| FCV | Flow control valve |
| GEN | Generator |
| LE | Level element |
| LIT | Level indicator and transmitter |
| LOS | Local operator station |
| LS | Level switch |
| LSH | Level switch high |
| LSL | Level switch low |
| LSHH | Level switch high-high |
| LSLL | Level switch low-low |
| M | Mechanical equipment or mixer |
| FE | Flow element |
| FIT | Flow indicator and transmitter |
| P | Pump |
| PCV | Pump control valve |
| PE | Pressure element |
| PI | Pressure indicator (gauge) |
| PIT | Pressure indicator and transmitter |
| PSH | Pressure switch high |
| PSHH | Pressure switch high-high |
| PSL | Pressure switch low |
| PSLL | Pressure switch low-low |
| PRV | Pressure relief valve |
| SOV | Solenoid valve |
| TE | Temperature element |
| TIT | Temperature indicator and transmitter |
| TS | Temperature sensor |
| QS | Vacuum sensor |
| WE | Weight element |
| WG | Weir gate |
| WIT | Weight indicator and transmitter |
| XA | Alarm beacon |
| YS | Misc. alarm element |
| ZIT | Position indicator and transmitter |
Table 1-3 Unit Process Numbers (B)
| Unit Process Number | Unit Process Description |
| 100 | Raw water |
| 200 | Clarification |
| 300 | Media Filtration |
| 400 | High lift pumping |
| 500 | Chlorination |
| 600 | Chemical feed systems and backup power |
| 700 | Backwash waste pumping |
| 800 | Highland booster pumping |
| 801 | Highlands water storage reservoir |
| 802 | 7th Street water storage reservoir |
Loop Number (C) – A loop is a set of instruments (i.e. pH meter/transmitter), controls (i.e. hand switches), alarms, lights, etc., which monitor or control a particular process at the treatment plant. A complete list of each loop is beyond the scope of this manual. However, general information can be found in Division 13 of the project specifications.
Unit Number (D) – A unit number is included when there are multiple pieces of identical equipment.