Project Scope

ITEM	DETAILS
Equipment	Tower / Distillation Column
Quantity	Multiple units
Code / Standard	GB/T 150 (Pressure Vessels)
Key Materials	Shell: Q345R; Internals: 0Cr18Ni9 (TP304) trays and support rings; Skirt: Q345R
Client	Industrial end-user
Year	2019
Project	Wulian Factory Project — Process Tower Equipment

Client Background

The Wulian Factory Project is an industrial processing facility requiring multiple process towers for distillation, absorption, and stripping operations. Process towers are among the most challenging pressure vessels to fabricate due to their height, the complexity of internal components, and the demanding dimensional tolerances required for proper tray hydraulics and column performance.

Engineering Challenges

Process tower fabrication combines large-scale pressure vessel work with precision internal installation:

• Large-scale shell section fabrication and alignment — Tall towers are fabricated in multiple shell sections that must be aligned to tight verticality and roundness tolerances during final assembly. Each section must maintain shell roundness within GB/T 150 limits to ensure proper internal tray fit and seal. Weld joint misalignment between sections can cause internal flow maldistribution and reduced separation efficiency.
• Internal tray and distributor installation — Column internals — including sieve trays, downcomer panels, liquid distributors, and support rings — must be installed with precise levelness and proper clearances. Tray levelness directly affects liquid distribution and vapor flow patterns across the column diameter. Each tray must be checked for level at multiple points and adjusted before permanent fastening.
• Wind and seismic load design — Tall process towers are subject to significant wind loads and must be designed for the seismic zone of the installation site. The skirt-to-shell junction, anchor bolt pattern, and foundation ring design must account for combined pressure, dead weight, wind, and seismic loading conditions per the applicable structural codes.

How Lmart Delivered

Lmart's column fabrication experience and internal installation capability ensured compliant delivery:

• Controlled shell rolling and section alignment — Shell plates were rolled on Lmart's plate rolling machine with monitored roundness checks at multiple points along each section. Section-to-section fit-up was verified using internal reference lines and laser alignment tools to maintain overall tower straightness within specification.
• Precision internal installation — All trays and distributors were trial-fitted in the horizontal position, checked for levelness, and adjusted before the tower was erected vertically. Support ring welds were performed with controlled heat input to minimize distortion. Final internal inspection was performed with the tower vertical, verifying tray levelness using precision spirit levels at multiple radial points.
• GB/T 150 fabrication with structural analysis — The tower was fabricated per GB/T 150 pressure vessel requirements with additional structural calculations per wind and seismic loading conditions for the installation site. The skirt-to-shell junction design was verified by finite element analysis (FEA) at the critical base-ring stress locations.

Delivery Evidence

• GB/T 150 supervision inspection certificates from local TSG authority
• Hydrostatic test records at code-required pressure for the complete tower assembly
• Internal tray levelness survey reports with measurement data at all tray elevations
• Complete vendor data book including material certificates, weld maps, NDE reports, dimensional records, and internal installation verification documentation
• Tower sections delivered on schedule with road transport permits for oversized cargo

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