Project Overview

A Client reviewed their high-pressure hydrogen shell & tube heat exchangers during a process hazard assessment (PHA). The study found that cooling water tube passes for two exchangers were insufficiently protected in the event of a tube rupture. The original protection scheme – a common thermal PSV on the combined cooling water discharge header – was deemed not large enough to prevent damage if a tube ruptured. Rally was asked to provide an engineered solution to the PHA action item.

Overpressure Protection main Overpressure Protection first

Scope Definition

In the event of a tube rupture, the high-pressure hydrogen from the shell pass would enter the low-pressure tube pass. The resulting overpressure in the cooling water system risked a hydrogen gas release or further equipment damage.
The Client’s process group recommended adding dedicated overpressure protection devices to the tube side of each cooler to mitigate the risk.

Detailed Deliverables

Rally provided process engineering support to size two new rupture disks for each heat exchanger.
Rally produced a construction work package (CWP) that detailed the piping modifications necessary to install the new rupture disks. A second CWP was issued with pre-fabrication and installation instructions for new structural steel supports.
Rally also provided a capital cost estimate (CAPEX) based on the IFC construction work packages, to support the Client’s AFE process.

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