Boiler Surveys & Walkdowns: What We Found at a Caribbean Power Plant's HRSG

Apr 28, 2022
3 min read

Updated: Aug 6

We recently performed a boiler walkdown at a power plant in the Caribbean. After surveying the facility's HRSGs, we observed that many of the gages were neglected or out of service. Following discussions with plant personnel, they saw clear value in replacing their old gages — especially the bicolor gage located at the HP drum — with Simpliport® 180 Bi-Color Ported Water Gage Glasses.

Understanding HRSG Drum Configuration

The HP (high-pressure) drum is the primary drum in an HRSG (Heat Recovery Steam Generator). Air and heat flow through the ductwork is closely monitored for safe and proper operation, and the HP drum is central to that monitoring.

The IP (intermediate-pressure) and LP (low-pressure) drums, when present, operate using residual heat after it has passed through the HP segment of the HRSG. Depending on the capacity and configuration of a given HRSG, a unit may not always have an IP or LP drum — some units have just one drum, while others have two or all three.

This matters for level instrumentation planning: each drum present in the configuration needs its own reliable, ASME-compliant level indication, and a facility surveying its HRSG needs to account for however many drums its specific unit has.

What the Walkdown Revealed

At this facility, the survey found gages that were neglected or out of service — a common finding on aging HRSG installations where gage visibility issues can lead operators to stop relying on a hard-to-read instrument altogether, rather than flag it for replacement.

This is precisely why visibility matters so much for boiler water level gages: it's critical to see boiler water level at any angle, any distance. Wherever an operator is standing within 180 degrees of the Simpliport Wide Angle Hood, they can clearly see the bright red or green indication of steam and water level — decreasing exposure time to the boiler environment while still maintaining the crystal-clear, direct-reading view ASME requires.

Why This Matters Beyond One Facility

Gages that go neglected or out of service represent a gap in the redundant level verification ASME code is designed to provide. A facility might not even realize how many of its gages have degraded to the point of being effectively unused until a structured survey is performed.

Virtual or Onsite Boiler Surveys & Walkdowns

Having application issues or concerns with your level instrumentation? Clark-Reliance experts are available for virtual or onsite boiler surveys and walkdowns of boilers and process equipment.

What a Survey Typically Covers:

Inspection of all gage glasses and level indicators for visibility and condition
Assessment of whether existing instrumentation meets current ASME code requirements
Evaluation of HP, IP, and LP drum instrumentation (as applicable to the unit's configuration)
Identification of gages that are neglected, degraded, or effectively out of service
Recommendations for upgrades where visibility or reliability issues are found

Virtual vs. Onsite:

Virtual surveys can review documentation, photos, and video walkthroughs provided by plant personnel to assess instrumentation condition and code compliance remotely. Onsite surveys involve a Clark-Reliance representative physically walking the facility alongside plant staff for a direct, hands-on assessment.

Why Regular Surveys Matter

Gage degradation is often gradual — a gage that's slightly harder to read this year than last year rarely triggers a maintenance request on its own. A structured, periodic survey catches this kind of slow drift before it results in a facility relying on multiple compromised instruments simultaneously.

Applications

Boiler surveys and walkdowns are valuable for:

Power Generation: HRSG and conventional boiler instrumentation audits
Facilities Planning Upgrades: Establishing a baseline before a modernization project
Aging Infrastructure: Identifying accumulated instrumentation issues across older units
New Plant Personnel: Building familiarity with existing instrumentation condition