Heat exchanger design, manufacturing & repair
With the extensive engineering and manufacturing capacity to respond from five locations and nearly 500,000 ft² of manufacturing space, Ohmstede Ltd. can build multiple units with short lead times in a very efficient manner. The company is able to take on jobs of all sizes, often coordinating with several locations simultaneously to complete customer projects quickly.
The company fabricates units ranging from pipe-sized lube oil coolers to giant 182-inch diameter equipment weighing in excess of 600,000 lbs. Whether the material is carbon steel, low chrome, duplex stainless, high nickel alloy or reactive metals, Ohmstede Ltd. can fabricate to customers’ exacting specifications.
Ohmstede Ltd’s team of experienced mechanical and thermal engineers and designers works directly with your professional staff to meet specific needs and design requirements. Ohmstede Ltd’s personnel are well versed in ASME BPVC Section I & VIII-1, TEMA, API-660 and their customer specifications. Ohmstede Ltd. uses the latest versions of COMPRESS, PVElite/CodeCalc, Solidworks, RCS, AutoCad and HTRI software for sizing, mechanical design, and thermal/vibration analysis. We also use specially licensed technology to provide engineered solutions for heat exchanger vibration and pressure drop issues such as McDermott/Lummus Helical Baffle Technology (Helixchanger® Heat Exchanger) baffles and ExxonMobil anti-vibration tube supports.
Fabrication shop capabilities & expertise
Manufacturing heat exchangers requires tight machining tolerances and welds that must conform exactly to approved weld procedures. Ohmstede Ltd’s shop capabilities in Texas and Louisiana are vast and each facility is self-sufficient with all the equipment required to produce and repair existing heat exchangers. Multiple manufacturing locations, specialized equipment and proprietary processes, give Ohmstede Ltd. the capability to handle every job from one unit to multiple units, whether for a capital project, a quick turnaround or an emergency response.
Ohmstede Ltd’s specialized machining and drilling is equipped with state-of-the-art machine tools with the capability to machine 12 tubesheets up to 13.5-inches thick simultaneously. All the components for replacement or new tube bundles can be produced within hours utilizing their excess capacities and project coordination.
In Ohmstede Ltd’s Sulphur, Louisiana shop, semi-automated welding equipment is used for overlay and clad restoration. Specialized electroslag weld strip technology enhances Ohmstede Ltd’s ability to work effectively with higher alloys, specifically 1-1/4Cr and 2-1/4Cr, stainless and high-nickel alloys. Ohmstede Ltd. also utilizes multiple weld heads / wire feeds and narrow gap techniques to improve efficiency. Low chrome material in weld joints over 9” thick have been completed with these capabilities. Many of the heat exchangers destined for harsh service are built in the Sulphur facility, where custom-designed equipment is used for overlaying steel and welding high alloy heat exchanger components.
Ohmstede Ltd’s specialized shop services include a clean room for welding reactive metals such as titanium, heat treating ovens for stress relieving, off-site exchanger cleaning facilities (hydroblasting, media blasting, a decoking oven), semi-automatic tube welding equipment to assure high quality tube-to-tubesheet welds every time and engineered tube rolling equipment. All shops comply with the requirements of the ASME Code and National Board certification. The company has more than 1,100 welding procedures and is certified for code stamps “R,” “U” and “S”.
Ohmstede Ltd. offers four methods for producing clad structures: Roll Bond Clad, Explosive Clad, Weld Overlay and Electroslag Strip Clad. Project managers and design engineers work with customers to help determine the best option for various applications and often a combination of these processes are utilized to meet all of the different geometries on the exchanger.