RCO Catalyst Bed-Depth Verification: Prove What Was Installed Before Performance Testing

An RCO catalyst bed can look complete from an access opening while still containing the wrong installed quantity, uneven layer depth, damaged modules or undocumented substitutions. These conditions can change residence time, pressure drop and flow distribution, yet they are difficult to reconstruct after the vessel is closed.

For a new installation, catalyst replacement or partial top-up, the useful question is not simply whether catalyst is present. The release decision should be based on traceable delivery records, an agreed loading plan, physical measurements and a documented final condition.

Start with the approved loading basis

Before opening packages, confirm the catalyst type, module or pellet dimensions, specified quantity, number of layers, nominal bed depth and vessel zones. Record approved substitutions and the person authorized to accept them. Do not infer installed volume from a purchase-order total alone: packaging, spare quantity and partial deliveries can create a misleading number.

Create a loading map that divides the bed into identifiable rows or zones. Link each zone to batch or pallet references where practicable. This makes later damage, settlement or performance questions easier to isolate.

Reconcile delivered and installed quantities

Use packing lists, receiving records and retained labels to reconcile delivered, rejected, spare and installed quantities. Photograph package labels before disposal. For modular catalyst, record module counts and positions. For loose media, document bag or container counts and the controlled method used to estimate the final volume.

A numerical reconciliation is evidence, not proof by itself. It should agree with the physical bed inspection and any retained spare stock.

Measure bed depth and levelness

Measure from stable reference points at multiple locations across the accessible bed. A single center measurement cannot reveal a low corner or a ridge created during loading. Record the measurement grid, tool, reference surface and actual readings rather than only writing “level.”

Compare readings with the approved design tolerance. Any acceptance limit should come from the project specification or supplier documentation; it should not be invented during inspection. Investigate unexplained variation before adding material, because an apparent low area may indicate a support, seating or distribution problem below.

Inspect module condition and interfaces

Check for chipped corners, cracked blocks, crushed seals, open gaps and modules that are proud of adjacent rows. Verify that retainers and seals match the approved arrangement and do not obstruct the intended flow area. For layered beds, confirm that each layer was completed and accepted before the next layer concealed it.

Keep loose debris out of catalyst passages. Where cleaning is required, use a method approved for the catalyst form and retain evidence of the final clean condition.

Build a release record before closure

The close-out package should contain the approved loading drawing, material certificates where required, packing and batch references, quantity reconciliation, measurement grid, photographs by zone, nonconformance dispositions and final sign-off. Photograph the completed bed with orientation references so the images remain meaningful later.

Before closing the vessel, verify that tools, packaging and temporary protection have been removed. Record access-cover closure and any required leak check as separate steps.

Connect loading evidence to startup data

During initial operation, compare pressure drop, temperature profile and operating flow with the approved baseline. Loading evidence helps the team interpret an abnormal result without immediately blaming catalyst chemistry. It also gives buyers and suppliers a common factual record when a performance test requires investigation.

SERNO can review RCO catalyst replacement scopes, loading records and performance-test readiness against actual process and project requirements. Share the gas composition, flow range, catalyst arrangement and available inspection evidence for a project-specific review.

FAQ

Is the purchase quantity enough to prove the installed catalyst volume?

No. The purchase quantity may include spares, rejected packages or material not installed. Reconcile records with physical counts and bed measurements.

How many bed-depth measurements are required?

Use enough points to represent every relevant zone and reveal unevenness. The grid and tolerance should follow the approved design and inspection plan.

Can catalyst be added immediately when one area reads low?

First investigate the reason. A low reading may result from uneven loading, settlement, a support issue or the chosen reference point.

What should be retained after the vessel is closed?

Retain the loading map, quantity reconciliation, batch records, measurement grid, zone photographs, dispositions and signed release record.