---
title: "Water Tank Control Diagram — asset register"
doc_type: pid-asset-register
source: "pid-schema.jpg"
tags: [HV 7, TV 42 (top), TC 42, LAHH 91, LAH 91, HMY 91, LSH 91, LY 91, HMS 91, RÉSERVOIR DU HAUT, LV 41, FE 15, FE 14, FE 16, HV 6, HV 1, HV 2, TV 42 (bottom), TT 42, LT 41]
summary: "This P&ID depicts a water tank system with level and temperature controls. Water is supplied to an upper tank ('RÉSERVOIR DU HAUT'), which is monitored by level and temperature transmitters. Level is controlled by a level controller (LIC 41/LC 41) regulating a level valve (LV 41) on the inlet, while temperature control involves a temperature controller (TC 42) actuating temperature valves (TV 42). Various alarms and switches are present for high level conditions."
---

# Water Tank Control Diagram

This P&ID depicts a water tank system with level and temperature controls. Water is supplied to an upper tank ('RÉSERVOIR DU HAUT'), which is monitored by level and temperature transmitters. Level is controlled by a level controller (LIC 41/LC 41) regulating a level valve (LV 41) on the inlet, while temperature control involves a temperature controller (TC 42) actuating temperature valves (TV 42). Various alarms and switches are present for high level conditions.

**Source:** pid-schema.jpg · **Components:** 23 (1 equipment, 14 instrument, 7 valve, 1 line)

## Equipment (1)

| Tag | Description | Details | Connects to |
|---|---|---|---|
| RÉSERVOIR DU HAUT | Water Tank | EAU | LSH 91, TT 42, LT 41, LV 41, line-32-17 |

## Instruments (14)

| Tag | Function (ISA 5.1) | Description | Details | Connects to |
|---|---|---|---|---|
| TC 42 | Temperature Controller, loop 42, shared display/control | Temperature Controller | — | TV 42 (top), TV 42 (bottom) |
| LAHH 91 | Level Alarm High-High, loop 91 | Level Alarm High-High | — | LAH 91 |
| LAH 91 | Level Alarm High, loop 91, shared display/control | Level Alarm High | — | LAHH 91, HMY 91 |
| HMY 91 | Hand Relay/Compute, loop 91, shared display/control | Hand Switch / Relay | Lumière alarme | LAH 91, TC 42, HMS 91 |
| LSH 91 | Level Switch High, loop 91 | Level Switch High | — | LY 91, RÉSERVOIR DU HAUT |
| LY 91 | Level Relay/Compute, loop 91 | Level Relay | — | LSH 91, HMS 91 |
| HMS 91 | Hand Switch, loop 91, shared display/control | Hand Switch | — | LY 91, HMY 91, TT 42 |
| FE 15 | Flow Element, loop 15 | Flow Element | — | LV 41, FE 14 |
| FE 14 | Flow Element, loop 14 | Flow Element | — | FE 15 |
| FE 16 | Flow Element, loop 16 | Flow Element | — | line-outlet |
| TT 42 | Temperature Transmitter, loop 42 | Temperature Transmitter | — | RÉSERVOIR DU HAUT, HMS 91 |
| LT 41 | Level Transmitter, loop 41 | Level Transmitter | — | RÉSERVOIR DU HAUT, LC 41 |
| LC 41 | Level Controller, loop 41, shared display/control | Level Controller | — | LT 41, LIC 41, LV 41 |
| LIC 41 | Level Indicator Controller, loop 41, shared display/control | Level Indicator Controller | — | LC 41 |

## Valves (7)

| Tag | Description | Details | Connects to |
|---|---|---|---|
| HV 7 | Hand Valve | — | TV 42 |
| TV 42 (top) | Temperature Valve (Solenoid) | Solenoid actuated | HV 7, TC 42 |
| LV 41 | Level Valve | Pneumatic actuator | LC 41, RÉSERVOIR DU HAUT, FE 15 |
| HV 6 | Hand Valve | — | HV 1 |
| HV 1 | Hand Valve | — | HV 6, HV 2 |
| HV 2 | Hand Valve | — | HV 1, TV 42 (bottom) |
| TV 42 (bottom) | Temperature Valve (Solenoid) | Solenoid actuated | HV 2, TC 42 |

## Lines (1)

| Tag | Description | Details | Connects to |
|---|---|---|---|
| line-32-17 | Process Line | 32-17, 2 32 EAU 5 | RÉSERVOIR DU HAUT |

## Notes on drawing

- Lumière alarme