KNOWLEDGE CLUSTER
Heat transfer
The largest knowledge cluster on this site. Articles explain engineering practice and how Ohm quotes from process data. They are not a substitute for a named code or a purchaser specification.
How to use this hub
Commercial intent (buy a heat exchanger in India) belongs on the product hub. How-to and comparison intent belongs here. Each article maps to one primary question so pages do not compete with each other in search.
Fundamentals
What the equipment is and how shell-and-tube flow works.
- What Is a Heat Exchanger? →A heat exchanger transfers heat between two process streams without mixing them. Duty, fluid allocation, and configuration are engineering decisions — not catalogue SKUs.
- How Does a Shell & Tube Heat Exchanger Work? →One fluid travels through the tubes; the other is driven across the bundle by baffles. Passes, LMTD, and nozzle design decide whether the unit makes duty without eating the pump.
- Types of Heat Exchangers →Name the type from duty and maintainability. Ohm manufactures four tubular configurations. Plate, air-cooled, and floating-head units are industry options — not items on this shop's SKU list.
Selection & sizing
Choose a configuration and assemble enough data to size it.
- How to Select a Heat Exchanger →Selection is a process decision first and a mechanical decision second. Start from fluids, duty, pressure, fouling, and cleaning — then choose the configuration Ohm can manufacture.
- How to Size a Heat Exchanger →Size from duty, LMTD, and a realistic U — then check pressure drop and vibration. Send complete stream data. Do not treat a website as a kW rating table.
- How to Prepare a Heat Exchanger Process Datasheet: A Field Engineer's Guide →An incomplete heat exchanger datasheet is the single biggest cause of delayed quotations and post-order design changes. Here is exactly what to include — and what manufacturers do when data is missing.
Design
Thermal and mechanical decisions that belong on the datasheet.
- Heat Exchanger Thermal Design →Thermal design sets area and layout so the dirty duty is met inside ΔP and without a vibrating bundle. Mechanical design then makes that geometry a pressure vessel.
- Heat Exchanger Mechanical Design →Mechanical design turns a rated bundle into pressure parts: tubesheets, shell, channels, nozzles, and an expansion scheme that matches the metal temperatures.
- Heat Exchanger Design Considerations →A working design balances thermal duty, hydraulics, mechanical integrity, and how the unit will be cleaned and inspected for the next decade.
- Heat Exchanger Pressure Drop →Allowable pressure drop is a process constraint, not a vendor preference. It decides baffle spacing, pass count, nozzle size, and sometimes whether the unit will vibrate.
Comparisons
One intent per page — do not rank these against the product hub.
- U-Tube vs Shell & Tube Heat Exchanger →Both are shell-and-tube family. The difference is the rear end: U-bends versus a second tubesheet. That choice governs expansion, cleaning, and leak repair.
- Fixed Tube Sheet vs Floating Head Heat Exchanger →Floating head is a TEMA rear-end family. Ohm builds fixed-tubesheet units, with or without a shell expansion joint, and U-tube as the removable-bundle option.
- Shell and Tube vs Plate Heat Exchanger: Choosing the Right Type for Your Process →Plate heat exchangers cost less and are more thermally efficient for clean services. Shell-and-tube handles higher pressures, temperatures, fouling services, and phase changes that plates cannot. The right choice depends on your specific process — not general rules.
Fouling, cleaning & failure
Operate and maintain the unit you already have.
- Heat Exchanger Fouling: Types, TEMA Allowances, Prevention and Cleaning Methods →Fouling is the number one cause of heat exchanger underperformance in operating plants. Understanding its mechanisms, specifying the correct fouling resistance, and selecting the right cleaning method prevents unplanned shutdowns.
- How to Reduce Heat Exchanger Fouling →Fouling is slowed by hydraulics, chemistry, and where you put the dirty fluid. Extra area without velocity control just delays the same shutdown.
- Heat Exchanger Cleaning Methods →Cleaning method is a design input. Straight tubes and a removable cover, a pullable U-bundle, or chemical-only access are decided on the GA — not at the first outage.
- Heat Exchanger Maintenance →Maintainability is designed in: channel access, bundle pull space, davits, and metallurgy. A unit that cannot be cleaned will not hold duty.
- Causes of Heat Exchanger Failure →Most exchanger failures are tube leaks, vibration wear, expansion damage, or gasket/partition leaks. Fix the mechanism; a larger replacement of the same layout will repeat it.
- Heat Exchanger Troubleshooting →If duty has fallen, decide whether the process changed, the unit is dirty, the bundle is bypassing, or a leak is mixing streams — before you buy a larger exchanger.
Standards & inspection
Codes as design practice; ISO as QMS — not fake stamps.
- Shell and Tube Heat Exchanger Types: TEMA Nomenclature Explained →TEMA's three-letter code system defines every shell-and-tube heat exchanger. Understand what each letter means, which configuration suits which service, and avoid costly specification errors.
- TEMA Classes R, B and C: What They Mean and How to Specify Correctly →TEMA Class R, B and C are not just labels — they specify tubesheet thickness, corrosion allowances, shell thickness minimums, tie-rod counts, and testing requirements. Specifying the wrong class costs money; specifying too light risks failure.
- ASME Section VIII Pressure Vessels: A Practical Guide for Buyers and Engineers →ASME Section VIII is the code that keeps pressure vessels from killing people. Division 1 or Division 2, U-stamp or UM-stamp, Form U-1 or U-1A — here is what each means and what you should demand from a certified fabricator.
- API 660 Heat Exchanger Overview →API 660 is a purchaser specification for shell-and-tube exchangers. Ohm designs to it when it is attached to the enquiry — it is not an Ohm certification.
- Heat Exchanger Inspection Checklist →Manufacturer checks prove the unit matches the approved drawing and ITP. Purchaser checks prove that is what you ordered. Do not mix the two lists.
- Heat Exchanger Testing Procedures →Pressure parts are hydrotested. NDT follows the ITP. Do not assume pneumatic or helium leak testing is standard on every Ohm unit.