18-Unit Compressor Ancillary Vessel Package for Dresser-Rand & Hanwha Chemical PE1 Revamping: 3-Stage Intercoolers, After Cooler, and Volume Bottles — ASME U + KGS

Lmart fabricated a complete 18-unit compressor ancillary vessel package for Dresser-Rand (now Siemens Energy) — three shell-and-tube intercoolers, one after cooler, and six pairs of pulsation volume bottles for a 3-stage reciprocating compressor system. The end user is Hanwha Chemical Corporation (now Hanwha Solutions) for the PE1 (Polyethylene Unit 1) revamping project in South Korea. All 18 units carry ASME U stamp with KGS certification for Korean domestic installation.

Customer (OEM)	Dresser-Rand (now part of Siemens Energy)
End User	Hanwha Chemical Corporation (now Hanwha Solutions)
Industry	Petrochemicals — polyethylene manufacturing
Project	PE1 Revamping — Polyethylene Unit 1 compressor retrofit
Equipment	Intercoolers × 6, After Cooler × 2, Volume Bottles × 10 (18 units total)
Design Code	ASME Section VIII, Division 1 (U Stamp) + KGS
Key Materials	SA-516 Gr. 70 (shells, volume bottles), SA-240 Type 304 (tube bundles)
Compressor Stages	3-stage reciprocating compressor system
Total Units	18 (9 item numbers × 2 units each)

Customer Background and Industry Context

Dresser-Rand, now operating as Siemens Energy Compression, is one of the world’s leading manufacturers of reciprocating and centrifugal compressors for the oil & gas, petrochemical, and industrial gas industries. With a history spanning over 100 years, Dresser-Rand designs and packages complete compressor systems — including the ancillary pressure vessels (intercoolers, aftercoolers, and pulsation dampeners) that are integral to the compressor train’s performance. As a global OEM, Dresser-Rand sources these ancillary vessels from qualified fabricators who can meet both ASME code requirements and the OEM’s own engineering specifications.

Hanwha Chemical Corporation (now Hanwha Solutions, Chemical Division) is one of South Korea’s largest petrochemical companies, operating polyethylene, PVC, and chlor-alkali plants. The PE1 (Polyethylene Unit 1) is a high-pressure polyethylene production facility that uses reciprocating compressors to compress ethylene gas to the pressures required for polymerization. Over time, these compressor systems require revamping — replacing worn internals, upgrading capacity, and installing new ancillary equipment — to maintain production efficiency and meet evolving product specifications.

In a reciprocating compressor system, the gas is compressed in stages, with intercoolers removing the heat of compression between each stage to improve efficiency and prevent excessive gas temperatures. Volume bottles (pulsation dampeners) are installed at the suction and discharge of each compression stage to attenuate pressure pulsations in the piping system, preventing vibration-induced fatigue failures in downstream equipment and piping. Together, these vessels form a tightly integrated package that must be designed, fabricated, and delivered as a matched set.

Challenges and Engineering Pain Points

OEM Specification Compliance: Dresser-Rand Engineering Standards

Fabricating for a major compressor OEM means meeting specifications that go beyond the base ASME code. Dresser-Rand imposes proprietary engineering standards covering dimensional tolerances (particularly nozzle locations and orientations that must align with the compressor package piping layout), weld quality requirements that may exceed ASME minimums, surface finish specifications on internals, and documentation formats that integrate with the OEM’s quality management system. Every deviation — even a minor dimensional variance on a nozzle projection — requires a formal Non-Conformance Report (NCR) reviewed by the OEM’s engineering team.

Shell-and-Tube Intercooler Fabrication with Mixed Materials

The three intercooler designs (1st, 2nd, and 3rd stage) and the after cooler use carbon steel shells (SA-516 Gr. 70) with stainless steel tube bundles (SA-240 Type 304). This bimetallic construction introduces dissimilar metal welding at the tubesheet-to-shell joint, requiring qualified welding procedures for carbon steel-to-stainless steel transitions. The tube-to-tubesheet welds — hundreds of individual welds per exchanger — are critical joints that must be leak-tight at operating pressure and temperature while accommodating differential thermal expansion between the carbon steel shell and stainless tube bundle.

Pulsation Volume Bottle Dimensional Precision

Volume bottles serve as acoustic filters in reciprocating compressor piping systems. Their internal volume, nozzle locations, and internal baffle configurations are determined by pulsation analysis (API 618) and must be fabricated to precise dimensions to achieve the target pulsation dampening performance. Unlike conventional pressure vessels where modest dimensional variations are acceptable within ASME tolerances, volume bottle dimensions directly affect the acoustic response of the compressor piping system. Nozzle-to-nozzle distances, internal choke tube lengths, and baffle positions are engineering-critical dimensions that the OEM verifies during final inspection.

Matched-Set Production: 9 Designs × 2 Units Each

Producing 18 vessels across 9 different designs as a coordinated delivery requires careful production planning. Each pair must be identical within fabrication tolerances — the two units of each design are installed on duplicate compressor trains, and any dimensional inconsistency between the pair creates installation problems. Production sequencing must also balance workshop loading: the intercoolers require different fabrication operations (tube bundle assembly, tube rolling, hydrostatic test of both shell and tube sides) than the volume bottles (simpler shell-and-head construction but tighter dimensional controls).

Why Dresser-Rand Selected Lmart

OEM-qualified fabricator for compressor ancillary vessels. Lmart is an approved vendor in Dresser-Rand’s supply chain for pressure vessels, having previously demonstrated compliance with the OEM’s engineering specifications, quality requirements, and documentation standards. Qualification as a Dresser-Rand supplier involves facility audits, welding procedure reviews, and trial fabrication — a barrier to entry that limits the pool of eligible fabricators.

Mixed-material heat exchanger capability. The intercoolers and after cooler require carbon steel/stainless steel bimetallic construction with qualified dissimilar metal welding procedures. Lmart’s workshop routinely fabricates shell-and-tube exchangers with mixed metallurgies, including the tube-to-tubesheet expansion and welding operations that are the most critical quality-control points in exchanger fabrication.

Batch production efficiency. An 18-unit order with 9 designs requires a fabricator who can manage parallel production streams without quality degradation. Lmart’s production planning system tracks each vessel independently through the fabrication sequence while maintaining material traceability (heat numbers, weld maps, NDE records) across all 18 units simultaneously.

ASME + KGS dual certification. As with the Air Products Ulsan 6 project, Korean installation requires both ASME U stamp and KGS approval. Lmart’s established KGS inspection coordination eliminates the schedule risk associated with first-time KGS certification attempts.

Engineering and Manufacturing Solution

The 18 vessels divide into two distinct fabrication categories: shell-and-tube heat exchangers (intercoolers and after cooler) and plain pressure vessels (volume bottles), each following different production workflows.

Intercoolers and After Cooler (Items 1–3)

The three intercooler designs and the after cooler are shell-and-tube heat exchangers that remove the heat of compression between each stage of the reciprocating compressor. As compression stage number increases, the gas volume decreases and the pressure increases — which is reflected in the decreasing vessel diameters across the three stages:

• 1st Stage Intercooler (WIN52525KK1) — DN273 × 8 × 2550 mm, the largest of the three, handling the highest volume flow at the lowest pressure
• 2nd Stage Intercooler (WIN52525KK2) — DN219 × 8 × 2300 mm, intermediate volume and pressure
• After Cooler (WIN52525KK3) — DN168 × 8 × 2200 mm, final cooling after the last compression stage

All three use SA-516 Gr. 70 carbon steel shells with SA-240 Type 304 stainless steel tube bundles. The 304 stainless tubes provide corrosion resistance against the process gas (ethylene with potential trace contaminants) while the carbon steel shell handles the cooling water circuit. Tube-to-tubesheet joints are strength-welded and hydraulically expanded to ensure leak-tight performance under the cyclic pressure loading characteristic of reciprocating compressor service.

Pulsation Volume Bottles (Items 4–9)

The six volume bottle designs cover suction and discharge service across all three compression stages. Each stage has a matched pair of suction and discharge bottles that attenuate pressure pulsations generated by the reciprocating action of the compressor pistons:

• 1st Stage — DN406 bottles (largest diameter) handling the highest volume, lowest pressure gas
• 2nd Stage — DN273 bottles at intermediate conditions
• 3rd Stage — DN219 bottles (smallest) at the highest pressure, lowest volume conditions

All volume bottles are constructed in SA-516 Gr. 70 carbon steel with 10 mm wall thickness. The consistent wall thickness across all six designs — despite the varying diameters — reflects the increasing design pressure at smaller diameters: the higher-pressure 3rd stage bottles require proportionally thicker walls relative to their diameter, which happens to converge at the same 10 mm nominal thickness as the larger but lower-pressure 1st stage bottles.

Internal components include choke tubes, baffles, and nozzle extensions positioned according to Dresser-Rand’s pulsation analysis results. These internals are tack-welded and continuously welded per the OEM’s drawings, with dimensional verification of all internal component positions before head closure.

Complete Equipment Specifications

#	Item No.	Equipment	Qty	Material	Size (DN × THK × L)	Unit Weight (kg)
1	WIN52525KK1	Inter Cooler-1 (1st Stage)	2	Shell: SA-516 Gr. 70 / Tube: SA-240 304	DN273 × 8 × 2550	502.4
2	WIN52525KK2	Inter Cooler-2 (2nd Stage)	2	Shell: SA-516 Gr. 70 / Tube: SA-240 304	DN219 × 8 × 2300	379.5
3	WIN52525KK3	After Cooler (Final Stage)	2	Shell: SA-516 Gr. 70 / Tube: SA-240 304	DN168 × 8 × 2200	228.0
4	FIN52670CJ1	1st Stage Suction Volume Bottle	2	SA-516 Gr. 70	DN406 × 10 × 2032	340.1
5	FIN52670CJ2	1st Stage Discharge Volume Bottle	2	SA-516 Gr. 70	DN406 × 10 × 1422	286.0
6	FIN52670CJ3	2nd Stage Suction Volume Bottle	2	SA-516 Gr. 70	DN273 × 10 × 1524	224.9
7	FIN52670CJ4	2nd Stage Discharge Volume Bottle	2	SA-516 Gr. 70	DN273 × 10 × 1118	169.3
8	FIN52670CJ5	3rd Stage Suction Volume Bottle	2	SA-516 Gr. 70	DN219 × 10 × 991	116.7
9	FIN52670CJ6	3rd Stage Discharge Volume Bottle	2	SA-516 Gr. 70	DN219 × 10 × 787	103.6
Total: 9 designs × 2 units each			18

All 18 units: ASME U stamp + KGS certification

Project Execution, Quality Control, and Delivery

Production was organized into two parallel streams: heat exchangers and volume bottles. The intercoolers and after cooler followed the shell-and-tube fabrication sequence, while the volume bottles followed the standard pressure vessel workflow with additional dimensional hold points for internal component positioning.

Key QC milestones:

• Incoming material verification: SA-516 Gr. 70 plate and SA-240 Type 304 tube/plate mill certificates reviewed against ASME SA-20 requirements, PMI verification on all stainless components
• Shell fabrication with longitudinal and circumferential seam welding, RT per ASME UW-51
• Tube bundle assembly: tube-to-tubesheet drilling, tube insertion, hydraulic expansion, and tube-to-tubesheet strength welding with 100% visual and dye penetrant inspection
• Volume bottle internal component installation: choke tubes, baffles, and nozzle extensions positioned per OEM drawings with dimensional verification before head closure
• Dissimilar metal weld qualification verification (carbon steel shell to stainless tubesheet joint) per ASME Section IX
• Hydrostatic pressure test: shell side and tube side tested independently on heat exchangers; single-pressure test on volume bottles — all at 1.3× MAWP per ASME UG-99
• Dimensional final inspection per Dresser-Rand’s GA drawing tolerances, with particular attention to nozzle projection, orientation, and spacing
• KGS witness inspection at hold points coordinated with ASME Authorized Inspector schedule
• Dual documentation package: ASME MDR (U-1 forms) + KGS certification documents for all 18 units

All 18 vessels were crated and shipped as a consolidated package to the Hanwha Chemical plant site in South Korea, with packaging designed to protect nozzle faces and machined surfaces during ocean transit.

Results and Business Impact

The complete 18-unit vessel package was delivered on schedule, enabling Dresser-Rand to meet Hanwha Chemical’s PE1 revamping timeline. The matched-set delivery — all intercoolers, after cooler, and volume bottles arriving together — eliminated the installation sequencing risks that arise when vessels arrive from multiple suppliers on different schedules.

For Dresser-Rand, this project validates Lmart as a reliable single-source supplier for complete compressor ancillary vessel packages — a procurement model that simplifies the OEM’s supply chain by reducing the number of vendors, purchase orders, and quality surveillance activities required for a compressor retrofit project.

For Lmart, the Dresser-Rand/Hanwha project demonstrates two important market capabilities: first, the ability to serve global compressor OEMs as an approved vessel fabricator, which opens a recurring revenue stream tied to the OEM’s worldwide project pipeline; and second, proficiency in producing mixed-material shell-and-tube exchangers alongside plain pressure vessels as an integrated package — a versatility that many single-product fabricators cannot match.

Customer Voice

Dresser-Rand’s decision to source the complete 18-unit package from a single fabricator — rather than splitting intercoolers and volume bottles across separate vendors — reflects confidence in Lmart’s ability to manage multiple vessel types and production streams simultaneously while meeting the OEM’s quality and delivery requirements.

“All 18 vessels passed dimensional and quality inspection on first submission. The consolidated delivery simplified our installation schedule significantly.”

— Dresser-Rand project procurement (paraphrased from vendor performance review)

Note: Lmart respects client confidentiality. Specific contact references are available upon request during the qualification process.