Apex Petrochemical Complex

Sensor specifications

Monitored parameters across the plant. Units and severity bands are defined once in the digital twin and must be reused by future AI and UI phases.

Gas (H₂S)

Unit: ppm

Fixed-point electrochemical or IR H₂S detectors at breathing height and high points.

Why monitored

H₂S is toxic at low ppm and flammable at higher concentrations; Apex A12/C03 are sour-service.

Typical causes

Flange / packing leaks
Knockout drum overfill
Relief valve lift
Sampling station left open

Operating ranges

Band	Range	Label
normal	0–10 ppm	Normal
warning	10–25 ppm	Warning
danger	25–45 ppm	Danger
critical	≥ 45 ppm	Critical

Spec id: gas_h2s

Temperature

Unit: °C

RTD / thermocouple process and ambient temperature points.

Why monitored

Detects reactor excursions, steam superheat, and fire / heat-radiation events.

Typical causes

Catalytic runaway
Cooling failure
Steam leak
External fire exposure

Operating ranges

Band	Range	Label
normal	0–120 °C	Normal
warning	120–180 °C	Warning
danger	180–250 °C	Danger
critical	≥ 250 °C	Critical

Spec id: temperature

Pressure

Unit: bar(g)

Gauge pressure on vessels, headers, and compressor discharge.

Why monitored

Overpressure threatens vessel integrity; underpressure can indicate major leaks.

Typical causes

Blocked outlet
PSV failure
Compressor surge
Line rupture

Operating ranges

Band	Range	Label
normal	0–15 bar(g)	Normal
warning	15–28 bar(g)	Warning
danger	28–40 bar(g)	Danger
critical	≥ 40 bar(g)	Critical

Spec id: pressure

Smoke

Unit: % obscuration / m

Optical smoke and aspirating detection near boilers, MCC, and loading canopies.

Why monitored

Early fire indication before thermal cameras or heat detectors trip.

Typical causes

Incipient fire
Insulation smolder
Vehicle exhaust under canopy

Operating ranges

Band	Range	Label
normal	0–5 % obscuration / m	Normal
warning	5–15 % obscuration / m	Warning
danger	15–35 % obscuration / m	Danger
critical	≥ 35 % obscuration / m	Critical

Spec id: smoke

Worker Presence

Unit: persons

Badge / computer-vision headcount fused with zone access control.

Why monitored

Occupancy multiplies consequence of toxic or flammable releases; drives muster accounting.

Typical causes

Turnaround surge
Permit work
Evacuation incomplete

Operating ranges

Band	Range	Label
normal	0–8 persons	Normal
warning	8–15 persons	Warning
danger	15–25 persons	Danger
critical	≥ 25 persons	Critical

Spec id: worker_presence

Permit Status

Unit: state

Electronic permit-to-work validity (hot work, confined space, LOTO).

Why monitored

Simultaneous operations without valid permits elevate ignition and entry risk.

Typical causes

Expired permit
Scope change
Missing gas test

Operating ranges

Band	Range	Label
normal	1–1 state	Valid
warning	0–0 state	Expiring / review
danger	-1–-1 state	Invalid
critical	-2–-2 state	Required but missing

Spec id: permit_status

PPE Compliance

Unit: % compliant

Camera / gate checks for hard hat, H₂S monitor, FR clothing, and eye protection.

Why monitored

Non-compliance in sour and LPG zones increases fatality risk during releases.

Typical causes

Missing personal H₂S monitor
Incorrect FR layer
Bypassed gate

Operating ranges

Band	Range	Label
normal	95–100 % compliant	Normal
warning	85–95 % compliant	Warning
danger	70–85 % compliant	Danger
critical	0–70 % compliant	Critical

Spec id: ppe_compliance

Humidity

Unit: % RH

Ambient relative humidity at boilers and loading racks.

Why monitored

Affects static control, corrosion, and cooling performance.

Typical causes

Weather front
Steam venting
Cooling tower drift

Operating ranges

Band	Range	Label
normal	20–70 % RH	Normal
warning	70–85 % RH	Warning
danger	85–95 % RH	Danger
critical	≥ 95 % RH	Critical

Spec id: humidity

Valve State

Unit: % open

Position feedback on ESD, ROV, and critical control valves.

Why monitored

Stuck valves defeat isolation and quench strategies during upsets.

Typical causes

Actuator failure
Air supply loss
Incorrect lineup

Operating ranges

Band	Range	Label
normal	0–5 % open	Normal
warning	5–15 % open	Warning
danger	15–30 % open	Danger
critical	≥ 30 % open	Critical

Spec id: valve_state

Camera Detection

Unit: event score 0–100

AI vision for flame, smoke plume, PPE, and unauthorized vehicle paths.

Why monitored

Provides spatial confirmation when point sensors are ambiguous.

Typical causes

Visible flame
Vapor cloud
Intrusion
PPE breach

Operating ranges

Band	Range	Label
normal	0–30 event score 0–100	Normal
warning	30–55 event score 0–100	Warning
danger	55–80 event score 0–100	Danger
critical	≥ 80 event score 0–100	Critical

Spec id: camera_detection

Wind Speed

Unit: m/s

Anemometer / weather station for dispersion and muster planning.

Why monitored

Wind direction and speed govern toxic plume travel from A12/D09 toward assembly points.

Typical causes

Weather change
Storm front

Operating ranges

Band	Range	Label
normal	0–8 m/s	Normal
warning	8–15 m/s	Warning
danger	15–25 m/s	Danger
critical	≥ 25 m/s	Critical

Spec id: wind_speed