Detailed Engineering & Design

Detailed engineering is where a safety concept becomes something a contractor can build and an inspector can verify. It is unglamorous, document-heavy work, and it is where most fire and gas projects either become straightforward or become a dispute.

ZE-Tronics produces complete detailed design packages for fire and gas detection, alarm and suppression systems — from area classification through to issued-for-construction drawings.

Hazardous area classification

Every downstream decision about equipment certification depends on getting classification right. Over-classify and you pay a permanent premium on every device in the area. Under-classify and you have installed uncertified equipment in an explosive atmosphere.

We classify to IEC 60079-10-1 for explosive gas atmospheres and IEC 60079-10-2 for combustible dust, delivering:

• Source-of-release schedule identifying every credible release point, its grade and release rate
• Zone determination — Zone 0, 1, 2 for gas; Zone 20, 21, 22 for dust
• Gas group and temperature class assignment (IIA / IIB / IIC; T1–T6)
• Extent-of-zone calculations
• Classification drawings in plan and elevation
• Equipment certification requirements schedule, area by area

Where a classification already exists, we can perform a verification review — classification drawings often date from original construction and no longer reflect a decade of modifications.

Cause-and-effect matrices

The cause-and-effect matrix is the single most important document in a fire and gas system. It defines, unambiguously, what happens when each detector activates: which alarms sound, which valves close, which equipment trips, which zones isolate, which suppression releases — and, just as importantly, what does not happen.

Ambiguity here produces spurious trips (expensive) or failure to act (catastrophic). Our matrices specify:

• Every initiating device, individually identified
• Voting logic — 1ooN, 2ooN — and the reasoning behind it
• Executive actions per detection level, distinguishing low alarm from high alarm from confirmed fire
• Time delays with stated justification
• Manual override and inhibit provisions, with the conditions under which they may be used
• Fault and degraded-mode behaviour — what the system does when a detector fails, which is the case most matrices handle worst

Design package deliverables

System — architecture and block diagrams, detector and device layouts in plan and elevation, panel general arrangement, power supply and battery autonomy calculations, earthing and bonding design.

Electrical — cable schedules and block cable diagrams, loop diagrams for every field device, junction box schedules, cable routing with segregation from power circuits, intrinsic safety loop calculations.

Logic and configuration — cause-and-effect matrix, logic diagrams, alarm and setpoint schedules, HMI graphics specification, communication architecture and protocol definition.

Specification and compliance — equipment datasheets, per-device certification compliance schedule, SIL verification calculations, proof-test procedures and intervals, installation and commissioning specifications.

SIL verification — the step that is often skipped

SIL determination at FEED stage says what integrity level is required. SIL verification at detailed design proves the proposed architecture actually achieves it, by calculating probability of failure on demand from real device failure rate data, the chosen voting architecture, diagnostic coverage and the proposed proof-test interval.

If verification shows a shortfall, the fixes are architectural — more redundancy, better diagnostics, shorter proof-test intervals — and they must be made now. Discovering the shortfall after installation is a very different conversation.

Standards framework

IEC 61508 and IEC 61511 (functional safety) · IEC 60079 series (explosive atmospheres) · IEC 60529 (ingress protection) · NFPA 72 (fire alarm and signalling) · NFPA 2001 (clean agent suppression) · API RP 14C (offshore surface safety) · ISA TR84.00.07 (fire and gas mapping)

Frequently asked questions

Can you work from our existing FEED package?
Yes. We can take over from another party’s front-end work, though we will review its assumptions before building on them.

Can you produce documentation in Azerbaijani or Russian?
Yes. Deliverables can be issued in English, Azerbaijani or Russian, or bilingually where regulatory submission requires it.