Heat Recovery Steam Generator (HRSG) Installation JHA (Job Hazard Analysis / Activity Hazard Analysis)
Updated 2026-06-23
A Heat Recovery Steam Generator (HRSG) Installation JHA (Job Hazard Analysis / Activity Hazard Analysis) is the plan that keeps the crew installing an HRSG from falling from the towering structure, being crushed by the heavy modules, or overcome in the confined drums and ducts. HRSG installation erects the tall heat-recovery boilers that capture the gas turbine's exhaust heat to make steam in combined-cycle plants — combining the extreme-height structural work, the heavy module and component lifts, and the confined-space drum and duct entry. This guide walks through building a Heat Recovery Steam Generator (HRSG) Installation JHA that names the extreme-height, heavy-module-lift, and confined-space hazards and assigns the fall-protection, rigging, and confined-space controls that hold up in the field.
Why HRSG installation needs its own JHA
Heat recovery steam generator (HRSG) installation erects the large heat-recovery boiler that captures the exhaust heat from a gas turbine to generate steam (for the steam turbine in a combined-cycle plant) — a tall structure containing the tube modules/harps, drums, headers, ductwork, casing, and the stack, assembled from heavy modules and components. The hazards combine the extreme height (HRSGs are tall structures — the structural erection, module setting, and work occur at significant height, with fall hazards), the heavy module lifts (the tube modules/harps, drums, and components are very heavy, requiring major critical lifts), the confined spaces (the drums, headers, ductwork, and casing interiors are confined spaces entered for assembly and welding), and the welding, the falling-object hazards on the tall structure, and the eventual pressure and steam. The extreme height, the heavy module lifts, and the confined-space entry justify a dedicated JHA.
Breaking HRSG installation into steps
The steps for a Heat Recovery Steam Generator (HRSG) Installation JHA follow the HRSG:
- Erect the HRSG structural steel (extreme height)
- Rig and set the tube modules/harps (critical lifts)
- Rig and set the drums and headers (critical lifts)
- Install the ductwork, casing, and stack
- Weld and connect the pressure parts (confined spaces)
- Enter drums, headers, and ducts for work
- Manage height, lift, and confined-space hazards
- Hydrotest and prepare for commissioning
Each step carries a hazard, and the extreme-height work, the heavy module lifts, and the confined-space entry are where the most serious risks concentrate.
The hazards step by step
Extreme height
HRSGs are tall structures, and the structural erection, module setting, welding, and work occur at significant height, with fall hazards throughout, and falling-object hazards to workers below. The controls are comprehensive fall protection (100% tie-off, guardrails, safety nets where used), safe access (stairs, lifts, scaffolds), a rescue plan for at-height work, dropped-object controls and exclusion zones below, and managing the extreme-height exposure. The extreme height is pervasive. (These follow the working-at-height and steel-erection fundamentals.)
Heavy module lifts
The tube modules/harps, drums, headers, and components are very heavy, requiring major critical crane lifts to set on the tall structure, with rigging-failure, struck-by, crushing, and dropped-load hazards. The controls are engineered critical-lift plans, rated rigging and a qualified crane operator and rigger, verified weights and pick points, exclusion zones, tag lines, and keeping clear and out from under. The heavy modules lifted to height are demanding lifts. (These follow the rigging and critical-lift fundamentals.)
Confined spaces
The drums, headers, ductwork, and casing interiors are confined spaces, entered for assembly, welding, inspection, and cleaning, with atmospheric (welding fumes, purging gases), access, and the confined-space hazards. The controls are the full confined-space program (isolation, atmospheric testing and monitoring, ventilation, permit, attendant, rescue), and the confined-space welding controls (fume ventilation). (These follow the confined-space fundamentals.)
Welding and pressure parts
The extensive welding of pressure parts (fume, hot work, and the code-welding requirements) and the eventual pressure/steam carry their hazards. The controls are the welding controls (fume, hot work, fire watch), and the pressure-testing (hydrotest) and commissioning controls. (These follow the welding and boiler fundamentals.)
A simple Heat Recovery Steam Generator (HRSG) Installation JHA structure
| Step | Hazard | Control | Standard |
|---|---|---|---|
| Erect structure | Extreme-height fall | Fall protection, 100% tie-off, safe access, rescue | OSHA 1926.760 |
| Set modules/drums | Critical lift / crush | Engineered lift plan, rated rigging, verified weights, exclusion | OSHA 1926.1417 |
| Weld pressure parts | Fume / hot work | Welding controls, ventilation, fire watch | OSHA 1926.352 |
| Enter drums/headers | Confined-space | Full program, test/monitor, ventilate, attendant, rescue | OSHA 1910.146 |
| Work below | Dropped object | Dropped-object controls, exclusion zones below | OSHA 1926.759 |
| Hydrotest | Pressure | Hydrotest procedures, line-of-fire discipline | ASME BPVC |
Extreme height, heavy module lifts, and confined-space entry
A Heat Recovery Steam Generator (HRSG) Installation JHA centers on the extreme height, the heavy module lifts, and the confined-space entry. The extreme height is pervasive — the tall HRSG structure means fall and dropped-object hazards throughout — controlled by comprehensive fall protection, safe access, dropped-object controls, and a rescue plan. The heavy module lifts address the tube modules, drums, and headers set on the tall structure — controlled by engineered critical-lift plans, rated rigging, and verified weights. The confined-space entry addresses the drums, headers, and ducts — controlled by the full confined-space program. A JHA built on extreme-height fall protection, the heavy module lifts, and confined-space entry, with welding and pressure controls, addresses the hazards that define HRSG installation.
From the field: what actually goes wrong
In fourteen years across federal, heavy civil, and industrial projects, HRSG installation is dominated by the extreme height, because an HRSG is a tall structure and nearly all the work — structural erection, module setting, welding, and connection — happens at significant height. The fall hazards are pervasive, and the dropped-object hazards to workers below are constant given the height and the volume of components. The controls are comprehensive fall protection (100% tie-off, guardrails, nets where used), safe access, a rescue plan for at-height work, and dropped-object controls with exclusion zones below. The extreme height is the defining condition of HRSG work.
The heavy module lifts and the confined-space entry are the other defining hazards. The HRSG is assembled from heavy modules — the tube modules or harps, the drums, and the headers are very heavy and must be lifted to height and set on the tall structure, demanding critical lifts controlled by engineered plans, rated rigging, verified weights, and exclusion zones. And the drums, headers, ductwork, and casing interiors are confined spaces, entered for assembly, welding, and inspection, under the full confined-space program with attention to welding fumes and purging gases. On the projects I have run, the extensive pressure-part welding brings fume and hot-work hazards, and the eventual hydrotest and commissioning bring pressure hazards. The JHA built on extreme-height fall protection, the heavy module lifts, and confined-space entry is the one that protects the HRSG crew.
The bottom line
A Heat Recovery Steam Generator (HRSG) Installation JHA names the extreme-height, the heavy-module-lift, and the confined-space hazards with specific controls — comprehensive fall protection with dropped-object controls for the tall structure, engineered critical-lift plans with verified weights for the heavy modules and drums, and the full confined-space program for the drums, headers, and ducts. The extreme height, the heavy module lifts, and the confined-space entry are the defining hazards. The JHA that manages all three is the one that protects the crew.
Frequently asked questions
Why is extreme height the defining HRSG hazard?
HRSGs are tall structures, and the structural erection, module setting, welding, and work occur at significant height, with fall hazards throughout and dropped-object hazards to workers below. Controls are comprehensive fall protection (100% tie-off, guardrails, nets where used), safe access, a rescue plan for at-height work, dropped-object controls and exclusion zones below, and managing the extreme-height exposure.
What makes the module lifts critical lifts?
The tube modules/harps, drums, headers, and components are very heavy, requiring major critical crane lifts to set on the tall structure, with rigging-failure, struck-by, crushing, and dropped-load hazards. Controls are engineered critical-lift plans, rated rigging and a qualified crane operator and rigger, verified weights and pick points, exclusion zones, tag lines, and keeping clear and out from under.
What confined spaces does an HRSG have?
The drums, headers, ductwork, and casing interiors are confined spaces, entered for assembly, welding, inspection, and cleaning, with atmospheric (welding fumes, purging gases), access, and confined-space hazards. Controls are the full confined-space program (isolation, atmospheric testing and monitoring, ventilation, permit, attendant, rescue) and the confined-space welding controls.
What welding hazards apply to HRSG installation?
The HRSG involves extensive welding of pressure parts, with welding fume, hot work, and code-welding requirements, much of it in confined spaces and at height. Controls are the welding controls (fume ventilation, hot work, fire watch), the confined-space controls where welding is inside drums/headers, and the pressure-testing (hydrotest) controls when the pressure parts are complete.
Related JHAs
- Gas Turbine Installation JHA — the gas turbine feeding the HRSG
- Boiler Pressure Parts Installation JHA — the pressure-part fundamentals
- Steam Drum Installation JHA — the HRSG drums
- Steel Erection JHA — the structural erection at height
Written by Mustafa Tok, CSP, ASP, CHST — OSHA Authorized Outreach Trainer with 14+ years of international construction safety experience across federal, heavy civil, and industrial projects.