Both tube sheets are welded to the shell. The design is economical for low differential temperature and clean shell-side services — shell-side mechanical cleaning is limited once the bundle is installed.
In a fixed design, the tube sheets form a permanent weldment with the shell. Thermal growth is absorbed by the shell (sometimes with an expansion joint) rather than by a free floating head.
A fixed tube sheet exchanger welds both perforated sheets to the shell. Tubes are expanded and/or welded into the sheets. Because the shell-side cannot be fully withdrawn as a bundle, this layout suits services where shell-side fouling is low or chemical cleaning is acceptable.
When tube-side and shell-side metal temperatures diverge enough to stress the welds or tubes, designers may add a shell expansion joint. That decision belongs on the project datasheet — this page does not invent a ΔT threshold or thickness rule.
Compare the structural family on the hub types table, or continue to floating and U-tube when expansion or cleanability drives the choice.
| Structural arrangement | Both sheets welded to the shell |
| Thermal expansion | Shell growth / optional expansion joint; not a free floating head |
| Shell-side cleaning | Limited mechanical access after assembly |
| Typical service context | Low ΔT, relatively clean shell-side fluids |
| Governing context | ASME Section VIII / TEMA as named on the drawing |
Use the buyer's guide checklist, then send a drawing-led pack via the enquiry form or WhatsApp +91 95946 39793.
A fixed tube sheet design welds both perforated sheets to the shell so the tube bundle is not free to slide as a floating head. Tubes are joined to the sheets by expansion, welding, or both.
Fixed designs suit lower differential temperature and cleaner shell-side services where mechanical bundle withdrawal is not required. High ΔT or heavy fouling often pushes the design toward floating or U-tube — confirm against the datasheet.
No. Fixed ends still experience thermal stress. Designers may specify a shell expansion joint when metal temperatures diverge. There is no universal ΔT cutoff on this page.
Yes — send diameter, thickness, hole table, material and code notes via the enquiry form or WhatsApp. We review manufacturability; we do not invent a substitute design calculation.
Use the types comparison table on the tube sheets hub, then open the spoke pages for fixed, floating, U-tube and double designs.
Every enquiry is checked against governing code, material compatibility and manufacturing feasibility before a quote is issued. NPRO states ISO 9001 QMS and mill-test / NDT documentation practices on About — project-specific stamps or PED/CE are confirmed during enquiry, not assumed from this page.
Include drawing or envelope, material, joint method and code edition — we will confirm manufacturability before quoting.