U.S. Power Boiler and Heat Exchanger Manufacturing: An Investor Primer

1. Overview

North American Industry Classification System (NAICS) code 332410 covers U.S. factories that manufacture power boilers and heat exchangers.[1] These are engineered, safety-critical products used in power generation, nuclear plants, liquefied natural gas (LNG), refining, chemicals, defense, data centers and other industrial processes.

"Power boiler" is easily misread as "coal-power equipment." The classification actually includes industrial and marine steam-generating equipment, while the heat-exchanger side serves refining, chemicals, food processing, pulp and paper, LNG, nuclear, defense, data centers and other thermal-management applications. Graham, for example, sells heat-transfer and vacuum equipment into refining, chemicals, fertilizers, edible oils, food and beverage, pulp and paper, hydrogen, geothermal and nuclear applications.[5]

The industry combines attractive characteristics—qualification barriers, large installed bases and recurring replacement work—with difficult project economics. Fixed-price contracts, volatile metal costs and fabrication delays can turn revenue growth into losses.

Public investors generally access the industry through diversified equipment companies. Private investors have a broader opportunity set among specialist fabricators, family businesses, aftermarket providers and sponsor-backed platforms. There is no clean industry exchange-traded fund (ETF), and few public pure plays.

2. What It Is and How It Is Structured

A power boiler converts heat into high-pressure steam. A heat exchanger transfers heat between fluids without necessarily mixing them. Products include utility and industrial boilers, heat-recovery steam generators (HRSGs), condensers, shell-and-tube exchangers, plate exchangers and specialized nuclear components.

The classification includes manufacturers that also install their equipment. It excludes:

• Heavy-gauge metal tanks, classified under NAICS 332420.
• Low-pressure steam and hot-water heating boilers, classified under NAICS 333414.
• Installation without manufacturing, classified under NAICS 238220.[1]

Consequently, reports labeled "boiler market," "HVAC heat exchangers" or "pressure vessels" commonly overstate the addressable market for 332410 by combining products that Census deliberately excludes.[1]

NAICS is assigned at the establishment level, not the consolidated-company level. A diversified corporation may therefore have some factories in this industry while reporting substantial revenue from unrelated products or overseas operations.

The operating model is usually engineered-to-order. A supplier performs thermal-hydraulic and mechanical design, purchases carbon or alloy steel plate, tubing and components, fabricates and machines pressure-containing assemblies, performs code-qualified welding and nondestructive examination, tests the unit, and ships either finished equipment or modules for field assembly. Large jobs may include installation, commissioning and later inspection, repair or replacement parts. BWXT's commercial nuclear operation, for example, combines steam-generator and heat-exchanger fabrication with thermal-hydraulic design, vibration analysis, inspection, maintenance and component replacement.[6]

Ownership is mixed. Large public manufacturers compete alongside private-equity-backed platforms, foreign-owned subsidiaries, family businesses and regional custom fabricators. The Small Business Administration's federal-contracting size standard is 750 employees, although that definition should not be confused with an economic description of a typical small company.[3]

3. How Big It Is

Census Bureau County Business Patterns reported the following employer-establishment statistics for the U.S. industry:

The specified ground-truth statistics file was not present at the stated path. Consequently, total sales or receipts, firm count and the Herfindahl-Hirschman Index were not available and are not estimated here. No suppressed value is stated.

Historical evidence suggests a nationally fragmented rather than oligopolistic industry. An SBA analysis based on the 2012 Economic Census reported that the four largest firms accounted for 27.3% of industry receipts.[26] That ratio is too old to describe current concentration confidently, and no current authoritative concentration table was available. National fragmentation coexists with high concentration in individual niches—nuclear steam generators, naval propulsion equipment, utility-scale condensers, LNG brazed-aluminum exchangers and standardized package boilers require different facilities and qualifications. A manufacturer can possess substantial pricing power in a qualified niche without appearing dominant in six-digit NAICS data.

County Business Patterns covers employer establishments. It can miss nonemployer businesses, government production and fabrication performed inside establishments classified under another primary activity.[2] That matters for naval and other vertically integrated production, although this capital-intensive industry is less dominated by tiny operators than many service industries.

4. Investable Universe

Public companies

None of the principal public companies is a precise proxy for U.S. NAICS 332410 production.

International public exposure includes Alfa Laval, a publicly traded global heat-transfer, separation and fluid-handling company, and Miura, now the owner of Cleaver-Brooks. These can provide more diversified thermal-equipment exposure but add currency, accounting and geographic considerations.

Major private or strategically owned operators

• Cleaver-Brooks, an industrial boiler and burner platform, was acquired by Japan's Miura in May 2024.[9]
• Kelvion is a global heat-exchange platform. Apollo-managed funds completed the acquisition of a majority interest in January 2026, with Triton retaining a minority stake.[10][28]
• Babcock Power is privately held and owns brands spanning HRSGs, boiler systems and heat exchangers.[11]
• Fulton remains family-owned and manufactures industrial and commercial boiler systems.[12]
• Metalforms Heat Transfer, part of TransTech Group under Bridge Industries, acquired Koch Heat Transfer's North American business in September 2024.[13]
• API Heat Transfer and numerous regional code shops cover shell-and-tube, plate, air-cooled and specialty products. The Heat Exchange Institute's membership illustrates this mix of public companies, private specialists and service firms.[29]

5. How the Money Works

Most large products are engineered to order. Revenue therefore depends on customer capital spending, contract awards and backlog conversion rather than high-volume factory throughput.

Three economic models coexist:

• Projects: Large boilers and exchangers generate substantial revenue but carry engineering, procurement, fabrication and installation risk.
• Standard equipment: Smaller repeatable products offer shorter lead times and better factory utilization.
• Aftermarket: Replacement tubes, parts, inspections, repairs and upgrades typically provide steadier demand and better cash conversion. Babcock & Wilcox's parts revenue illustrates the importance of this installed-base business.[4]

Large contracts often use percentage-of-completion accounting. Reported profit is sensitive to estimated total cost, and a revised estimate can recognize an expected project loss immediately. Customer advances and milestone payments reduce working-capital needs; retainage, delayed approvals and inventory builds increase them.[4][5]

Profitability is moved by four variables more than by headline industry growth. First, product mix: proprietary designs, replacement parts and emergency service generally carry better economics than competitively bid new-build fabrication. Second, throughput and factory absorption. Third, contract execution: Graham reported fiscal 2026 gross profit of $57.8 million, or 23.5% of sales, with margin declining because of a heavier mix of lower-margin defense material receipts, approximately $1.0 million of incremental tariff cost and the non-recurrence of a training grant.[5] Fourth, installed-base and aftermarket content: inspection, retubing, spares, upgrades and emergency work are less dependent on greenfield capital spending and often have shorter cycles and better pricing.

Important inputs include carbon steel, stainless steel, nickel alloys, tubes, forgings, welding consumables, freight and skilled labor. The industry's output Producer Price Index rose 15.1% year over year in June 2026, while the steel-mill-products index increased 16.9%.[15][16] That does not imply higher margins: fixed-price jobs and delayed pricing pass-through can convert inflation into cost overruns. B&W says its fixed-price profitability can vary because of steel and labor inflation, tariffs, subcontractor performance, productivity, engineering complexity and liquidated damages. It attempts to price expected inflation into bids or negotiate escalation clauses, but cannot eliminate the exposure.[4]

The broader fabricated-metal-products sector operated at 76.9% capacity utilization in June 2026, below its 78.5% long-run average. This is only a broad NAICS 332 proxy, not a measurement of this six-digit industry.[14]

The best operating indicators are:

• Orders and book-to-bill ratio.
• Backlog quality, cancellation terms and expected margin.
• Aftermarket and service share.
• Pricing relative to metal and labor costs.
• Qualified fabrication capacity and welder availability.
• Customer advances, inventory and contract assets.
• Warranty claims, rework and project-loss provisions.

6. Demand Drivers

Electricity and data centers. The U.S. Department of Energy estimated that data centers consumed 4.4% of U.S. electricity in 2023 and projected a range of 6.7% to 12% by 2028.[17] Rising load can support new generation, combined-cycle plants and thermal-management equipment, although data-center cooling systems often fall partly outside this NAICS category. The winners in data-center thermal management are likely to be manufacturers with scalable air-cooled or liquid-cooling products and short lead times, not necessarily legacy utility-boiler shops.

Power-generation construction. Developers planned 86 gigawatts of U.S. generating-capacity additions for 2026, including 6.3 gigawatts of natural-gas capacity and 3.3 gigawatts of combined-cycle capacity.[18] Actual boiler and HRSG orders depend on permitting, financing and the technology mix, so planned capacity is not equivalent to firm demand. Solar and battery additions use little steam equipment, while combined-cycle gas, nuclear and on-site generation create more relevant opportunities.

LNG and industrial gases. North American LNG export capacity was forecast to rise from 11.4 billion cubic feet per day in 2023 to 24.4 billion in 2028, with five U.S. projects accounting for 9.7 billion cubic feet per day of additions.[19] EIA also reported announced North American projects that could add 13.9 billion cubic feet per day of U.S. liquefaction capacity between 2025 and 2029.[30] These projects require cryogenic exchangers, condensers and related process equipment.

Nuclear power. Reactor life extensions, maintenance, naval procurement and possible new construction support high-specification components. The federal government has established policy targets of 35 gigawatts of additional nuclear capacity by 2035 and 200 gigawatts by 2050; these are goals, not demand forecasts.[20] BWXT described itself as the only commercial heavy nuclear-component manufacturer in North America.[6]

Industrial replacement. Refineries, chemical plants, pulp and paper mills, food processors and other facilities replace corroded or inefficient equipment during scheduled outages. This installed-base demand is usually less volatile than new-plant construction.

Energy efficiency and industrial decarbonization. Waste-heat recovery, cogeneration, economizers, more efficient exchangers, carbon capture, hydrogen and alternative fuels require thermal equipment. DOE's Industrial Heat Shot targets cost-competitive technologies with at least 85% lower greenhouse-gas emissions by 2035.[31] Conversely, electrified process heating and industrial heat pumps can replace some fuel-fired boilers—the likely outcome is product substitution and retrofit demand, not a uniform decline in thermal-equipment spending. Coal-plant retirement reduces demand for traditional utility boilers.

7. Regulation

The American Society of Mechanical Engineers (ASME) Boiler and Pressure Vessel Code (BPVC) is the central qualification framework. Section I covers power boilers, Section VIII covers pressure vessels and Section III addresses nuclear components.[21] Certification, documented materials, approved welding procedures, traceability and nondestructive examination create both costs and competitive barriers. The National Board Inspection Code is adopted in most U.S. and Canadian jurisdictions for installation, inspection and repair.[32]

The Environmental Protection Agency's Boiler Maximum Achievable Control Technology (MACT) rules regulate hazardous-air-pollutant emissions from many industrial, commercial and institutional boilers.[22] These rules primarily affect customers' operating and retrofit decisions rather than the manufacturing plant itself. Changes in emissions limits can force controls, fuel conversions or retirement of old equipment, while prolonged permitting can delay new orders.

Nuclear suppliers face Nuclear Regulatory Commission (NRC) requirements, including quality-assurance and code provisions incorporated through Title 10 of the Code of Federal Regulations, Section 50.55a.[23] Qualification cycles can be long, but approved suppliers may enjoy durable positions.

Manufacturing operations also fall under Occupational Safety and Health Administration (OSHA) welding, cutting and hot-work standards.[24] State boiler laws, inspections and code adoption can differ.

Section 232 metal tariffs and related trade measures can alter the cost of imported plate, tubing and finished equipment.[25] Contract escalation clauses, domestic sourcing and quote validity periods are therefore important underwriting details.

8. Competitive Dynamics and Consolidation

Competition is fragmented by product, end market and qualification level. A regional shell-and-tube fabricator does not compete directly with a nuclear steam-generator supplier, even though both may share the same NAICS code.

The strongest competitive advantages are:

• ASME and nuclear qualifications.
• Proven welding, metallurgy and traceability systems.
• Proprietary thermal and mechanical designs.
• Installed-base drawings and service relationships.
• Ability to finance working capital and provide performance bonds.
• Reliable outage response and on-time delivery.

Scale helps with purchasing, engineering and bonding, but large organizations can struggle with custom-project execution. Smaller specialists can win through speed and niche expertise.

Recent transactions—including Baker Hughes/Chart, Miura/Cleaver-Brooks, Apollo/Kelvion and Metalforms/Koch Heat Transfer—show continued strategic and sponsor interest.[8][9][10][13][28] Consolidation can expand aftermarket reach and product breadth, but it does not eliminate local fabrication capacity or customer qualification requirements.

9. Risks

• Fixed-price overruns: Steel, labor, engineering or installation costs can exceed estimates.
• Project timing: Permitting, financing and customer approvals can delay or cancel orders.
• Quality failures: Leaks, weld defects or pressure failures can cause recalls, litigation and reputational damage.
• Customer concentration: A small number of utilities, engineering contractors or government programs may drive results. Graham's fiscal 2026 filing says two customers each represented more than 10% of revenue, while 85% of backlog was defense-related.[5]
• Cyclicality: Power, LNG, refining and chemical capital spending arrives in waves.
• Energy transition: Coal retirements reduce legacy demand, while electrified process heating and industrial heat pumps can replace some fuel-fired boilers. Heat exchangers are less exposed because heat pumps, hydrogen, carbon capture, LNG, nuclear and waste-heat recovery all require thermal-management equipment.
• Labor scarcity: Qualified welders, engineers and nuclear-quality personnel are difficult to replace. Pressure-boundary welding, machining, nondestructive examination and code inspection are not interchangeable with general fabrication labor.
• Trade exposure: Tariffs, foreign exchange and lower-cost imports affect competitiveness. The relevant exposure is not only price: delayed forgings, castings or qualified tubing can hold up an entire project and trigger liquidated damages.
• Working capital: Inventory, retainage and contract assets can consume cash despite reported profit.
• Technology and overbuild: Data-center, hydrogen, carbon-capture or advanced-reactor expectations may not translate into economic projects.

10. How to Invest and Outlook

Public investors should treat BW as the most direct listed exposure but weigh its balance-sheet and project-execution risks. GHM and BWXT offer higher-barrier defense and nuclear exposure; BKR and MOD provide diversified participation in cryogenic, industrial and data-center thermal systems. Appropriate comparisons include organic orders, book-to-bill, backlog margin, free cash flow, net debt and enterprise value relative to earnings before interest, taxes, depreciation and amortization (EBITDA).

Private investors can pursue specialist fabricators, service companies, replacement-parts suppliers and regional platforms. Diligence should normalize EBITDA for project adjustments, test backlog margins job by job, examine customer advances and bonding capacity, and separate recurring aftermarket earnings from volatile new-build revenue. Certification ownership, welder retention, warranty history and customer concentration can matter more than headline growth. The most defensible targets generally combine a qualified installed base, repeat replacement work, scarce welding and engineering talent, customer approvals and code credentials. A fabricator dependent on occasional greenfield projects and fixed-price bidding is a materially different investment from an aftermarket platform with recurring outages and replacement cycles.

The central underwriting mistake would be to apply a global "heat exchanger market" growth rate or an HVAC boiler multiple to a 332410 company. Investors instead need plant-level product mix, backlog quality, escalation clauses, aftermarket share, customer concentration, weld and engineering capacity, cancellation rights, milestone cash terms and historical estimate-at-completion performance.

Outlook—editorial judgment: The demand setup is constructive but uneven. Electricity growth, data-center infrastructure, LNG, nuclear refurbishment and industrial efficiency should support orders and aftermarket activity. Margin expansion is less certain because metal inflation, tariffs, scarce skilled labor and fixed-price execution can absorb that growth. The most attractive businesses are likely to be qualified niche leaders with recurring service revenue, disciplined contract terms and limited balance-sheet dependence.

Sources

1. U.S. Census Bureau, 2022 North American Industry Classification System Manual, 2022, https://www.census.gov/naics/reference_files_tools/2022_NAICS_Manual.pdf
2. U.S. Census Bureau, 2023 County Business Patterns: Table CB2300CBP, 2025, https://data.census.gov/table/CBP2023.CB2300CBP
3. U.S. Small Business Administration, Table of Size Standards, 2023, https://www.sba.gov/document/support-table-size-standards
4. Babcock & Wilcox Enterprises, Annual Report on Form 10-K for 2025, 2026, https://www.sec.gov/Archives/edgar/data/1630805/000163080526000018/bw-20251231.htm
5. Graham Corporation, Annual Report on Form 10-K for Fiscal 2026, 2026, https://www.sec.gov/Archives/edgar/data/716314/000119312526260688/ghm-20260331.htm
6. BWX Technologies, Annual Report on Form 10-K for 2025, 2026, https://www.sec.gov/Archives/edgar/data/1486957/000148695726000007/bwxt-20251231.htm
7. Modine Manufacturing, Annual Report on Form 10-K for Fiscal 2026, 2026, https://www.sec.gov/Archives/edgar/data/67347/000110465926066795/mod-20260331x10k.htm
8. Baker Hughes, Baker Hughes Completes Acquisition of Chart Industries, 2026, https://investors.bakerhughes.com/news/press-releases/news-details/2026/Baker-Hughes-Completes-Acquisition-of-Chart-Industries/default.aspx
9. Cleaver-Brooks, Miura Purchase of Cleaver-Brooks, 2024, https://cleaverbrooks.com/miura-purchase-of-cleaver-brooks
10. Apollo Global Management, Apollo Funds to Acquire Kelvion, 2025, https://ir.apollo.com/news-events/press-releases/detail/572/apollo-funds-to-acquire-kelvion-a-leading-global-provider
11. Babcock Power, About Babcock Power, 2026, https://www.babcockpower.com/about/
12. Fulton, About Fulton, 2026, https://fulton.com/about/
13. Metalforms Heat Transfer, About Metalforms Heat Transfer, 2024, https://www.metalformsheattransfer.com/about-metalforms-heat-transfer
14. Federal Reserve Board, Industrial Production and Capacity Utilization: Table 7, 2026, https://www.federalreserve.gov/releases/g17/current/table7.htm
15. Federal Reserve Bank of St. Louis, Producer Price Index: Power Boiler and Heat Exchanger Manufacturing, 2026, https://fred.stlouisfed.org/data/PCU332410332410
16. U.S. Bureau of Labor Statistics, Producer Price Index—Metals and Metal Products, 2026, https://www.bls.gov/regions/mid-atlantic/data/producerpriceindexmetals_us_table.htm
17. U.S. Department of Energy, DOE Releases New Report Evaluating Increase in Electricity Demand from Data Centers, 2024, https://www.energy.gov/articles/doe-releases-new-report-evaluating-increase-electricity-demand-data-centers
18. U.S. Energy Information Administration, Developers Plan to Add 86 Gigawatts of U.S. Generating Capacity in 2026, 2026, https://www.eia.gov/todayinEnergy/detail.php?id=67205
19. U.S. Energy Information Administration, North American LNG Export Capacity Is on Track to More Than Double by 2028, 2025, https://www.eia.gov/todayinenergy/detail.php?id=64128
20. U.S. Department of Energy, United States Sets Targets to Triple Nuclear Energy Capacity by 2050, 2024, https://www.energy.gov/ne/articles/us-sets-targets-triple-nuclear-energy-capacity-2050
21. American Society of Mechanical Engineers, Boiler and Pressure Vessel Code—2025 Edition, 2025, https://www.asme.org/codes-standards/bpvc-standards/bpvc-2025
22. U.S. Environmental Protection Agency, Boiler Maximum Achievable Control Technology, 40 CFR Part 63, 2026, https://www.epa.gov/stationary-sources-air-pollution/boiler-maximum-achievable-control-technology-mact-40-cfr-part-63
23. U.S. Nuclear Regulatory Commission, Title 10, Code of Federal Regulations, Part 50, 2026, https://www.nrc.gov/reading-rm/doc-collections/cfr/part050/full-text
24. Occupational Safety and Health Administration, 29 CFR 1910.252—Welding, Cutting and Brazing, 2026, https://www.osha.gov/laws-regs/regulations/standardnumber/1910/1910.252
25. U.S. Customs and Border Protection, Section 232 Tariffs Fact Sheet, 2025, https://www.cbp.gov/sites/default/files/2025-08/20250820_tariff_factsheet_0.pdf
26. U.S. Small Business Administration, Proposed Size Standards Rule, 2022, https://public-inspection.federalregister.gov/2022-08091.pdf
27. Chart Industries, Annual Report on Form 10-K for 2024, 2025, https://www.sec.gov/Archives/edgar/data/892553/000089255325000039/gtls-20241231.htm
28. Triton Partners, Triton Completes Majority Stake Sale of Kelvion to Apollo Funds, 2026, https://www.triton-partners.com/news/triton-completes-majority-stake-sale-of-kelvion-to-apollo-funds
29. Heat Exchange Institute, Member Directory, 2026, https://www.heatexchange.org/members/
30. U.S. Energy Information Administration, U.S. LNG Exports Reach Record High, 2025, https://www.eia.gov/todayinenergy/detail.php?id=66384
31. U.S. Department of Energy, Industrial Technologies Energy Earthshots, 2026, https://www.energy.gov/industrial-technologies/industrial-technologies-energy-earthshotstm
32. National Board of Boiler and Pressure Vessel Inspectors, National Board Inspection Code, 2026, https://www.nationalboard.org/PrintPage.aspx?pageID=102