Project Overview

Inspections revealed that the underbelly of a horizontal process vessel was corroding from aqueous acid attack. The client decided to replace the vessel with a new one during the next plant turnaround. Rally specified and procured a new vessel, with twice the corrosion allowance and improved detailing of the welds and nozzles along the underbelly to prevent liquid acid from pooling. The new vessel also features a larger manway for better inspection access. Simultaneously, the client asked Rally to replace the existing hard-to-read level sight glass with a modern magnetic-stripe instrument and level transmitter.

Replace Penex Receiver main Replace Penex Receiver first

Scope Definition

Rally met with the Client’s project team for a unit walk-through to confirm the scope of replacement and look for opportunities to improve the design. After developing a 3D model, a constructability study was done to plan the extraction of the old vessel and installation of the new one with minimal disturbance to adjacent piping and structures. The area was laser scanned prior to design to ensure there would be no fit-up issues or clashes during the next plant turnaround. The new vessel saddles were designed to work with the existing anchor bolts, saving time during construction.

Detailed Deliverables

A material requisition (MR) was developed for the new vessel, with an updated data sheet, fabrication notes, and inspection details. Bids were evaluated, then post-award vendor documents were managed with the successful bidder.

Separate MRs were developed and issued for the new level and pressure instruments. The level gauge was upgraded to Hastelloy C-276 for improved corrosion protection.

CWPs were issued for the vessel replacement, adjacent piping modifications, new cables and cable trays, and instrumentation upgrades.

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