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Codes & Compliance August 29, 2026

TSSA field approval combustion package Ontario | What a TSSA Field Approval Combustion Package Must Include — Ontario P.Eng Guide

What a TSSA Field Approval Combustion Package Must Include in Ontario

In Ontario, any industrial gas-fired appliance that exceeds standard certified appliance ratings — including custom burner systems, industrial furnaces, rotary dryers, mine air heaters, and thermal oxidizers — requires a formal Field Approval from the TSSA before installation.

Complete Combustion prepares complete TSSA Field Approval engineering packages under a PEO Certificate of Authorization.

What Triggers a TSSA Field Approval Requirement?

A TSSA Field Approval is required when an industrial gas-fired appliance cannot be certified under a standard appliance certification program. This applies to custom-built burner assemblies, modified certified equipment, high-capacity industrial systems, and field-assembled valve trains.

Core Documents Required in Every TSSA Field Approval Submission

1. Stamped P&ID or Combustion Schematic

Every submission requires a licensed P.Eng-stamped Piping and Instrumentation Diagram prepared to ANSI/ISA-5.1 standards, showing all fuel gas piping, dual SSOV configuration with POC switches, and HIGH/LOW pressure switches.

2. Valve Train Pressure Drop Calculations

A complete hydraulic pressure loss analysis demonstrating that the fuel train delivers the required pressure at the burner manifold under peak firing conditions.

3. NFPA 86 Pre-Purge Verification

Mathematical verification of minimum four air changes of the total combustion chamber volume before ignition is permitted.

4. Electrical Flame Safeguard Schematic

Complete BMS wiring schematic showing flame safeguard controller, flame scanners, airflow proving switches, and all safety interlocks.

5. Sequence of Operations & Bill of Materials

Step-by-step burner startup, modulation, and shutdown sequence, plus an itemized list of all fuel-wetted components with certification status.

Frequently Asked Questions

How long does TSSA Field Approval take in Ontario?
Typical review timelines are 4 to 8 weeks from submission. Incomplete submissions requiring revision cycles significantly extend this.
Can we start installation before Field Approval is granted?
No. The equipment must not be operated until the TSSA Field Approval is in hand.
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