OIL & GAS
The Most Expensive Turnaround Problems Often Start Before Shutdown
A replacement heat exchanger bundle can be fabricated exactly to specification and still create serious problems during a planned turnaround. The problem isn’t necessarily fabrication quality. The problem could be the information used to develop the specification in the first place.
In refineries and petrochemical facilities, exchangers may have been in service for decades. During that time, they may have undergone repairs, modifications, changes in operating conditions or repeated thermal cycling. At the end of the day, the original drawings and equipment datasheets may no longer tell the complete story.
Consider a few potential complications:
1
The replacement bundle doesn’t fit the existing shell as expected.
Shell distortion, internal deposits, previous repairs or differences between the original drawings and actual installed dimensions can complicate bundle insertion. Discovering these issues after the old bundle has been removed can create an immediate schedule problem.
2
A seemingly minor design change affects exchanger performance.
Changes in tube geometry, baffle configuration or material selection may affect pressure drop, thermal performance or susceptibility to flow-induced vibration. A replacement that fits mechanically still needs to perform under actual operating conditions.
3
The planned repair doesn’t account for the condition of the surrounding equipment.
Replacing a tube bundle doesn’t resolve damage to shell internals, gasket seating surfaces or other pressure-containing components. If those conditions aren’t understood until the exchanger is opened, the repair scope may need to change.
4
Fabrication decisions are made before installation constraints are fully understood.
Bundle extraction clearances, lifting arrangements and available field access can impose limitations that aren’t apparent from the equipment drawings.
None of these problems is inevitable. And not every condition can be identified before equipment is opened, but there is a significant difference between discovering a problem with months available to evaluate alternatives and discovering it when the exchanger is already out of service.
For EPCs, turnaround planners and asset owners, this is where earlier coordination with an experienced exchanger engineering and fabrication team can make a difference.
At Alliance Fabricating, we design, manufacture, repair and overhaul heat transfer and pressure equipment for demanding industrial applications. We’ve developed a technical pre-fabrication review checklist for teams preparing to repair, retube or replace shell-and-tube exchangers during a planned shutdown.
15 Technical Checks for Shell-and-Tube Exchanger Replacement During Planned Turnarounds
15 technical checks covering existing equipment geometry, thermal and mechanical compatibility, fabrication requirements, installation constraints and inspection contingencies.
GET IN TOUCH
We solve hard problems.
Bring us yours.
For in-service failures, use our 24/7 emergency line
+1 (519) 336-4328
ALLIANCE FABRICATING HEADQUARTERS
763 Chester St. Sarnia, Ontario N75 5N2