The stainless steel tube bundle is the core heat transfer assembly of a shell and tube heat exchanger. It consists of a specified number of stainless steel tubes, tubesheets, baffles, tie rods, spacer pipes, and sealing strips. The tube bundle is inserted into the shell, and the tubesheets are bolted or welded to the shell and channel flanges. One fluid flows through the tubes (tube side), and another fluid flows across the tubes inside the shell (shell side). The tubesheets separate the two fluids and provide structural support for the tubes. This product is manufactured in accordance with ASME Boiler and Pressure Vessel Code Section VIII Division 1, TEMA standards, and applicable ASME material specifications including ASME SA213, ASME SA312, ASME SA249, and ASME SA269.
ASME SA213 covers seamless ferritic and austenitic alloy steel boiler, superheater, and heat exchanger tubes. ASME SA312 covers seamless and welded austenitic stainless steel pipes. ASME SA249 covers welded austenitic stainless steel boiler, superheater, and heat exchanger tubes. ASME SA269 covers seamless and welded austenitic stainless steel tubes for general service. The tube bundle can be supplied with tubes manufactured to any of these specifications, depending on design pressure, temperature, corrosion allowance, and customer requirements.
Stainless steel tube bundles are available in the following austenitic grades:
TP304, TP304L, TP304H
TP316, TP316L, TP316H, TP316Ti
TP321, TP321H
TP347, TP347H
TP310S
TP317L
Duplex and super duplex stainless steel upon request
Fixed Tubesheet Bundle – Both tubesheets are welded or bolted to the shell. Tubes are fixed at both ends. An expansion joint is required on the shell when the temperature differential between tube and shell exceeds allowable limits.
Floating Head Bundle – One tubesheet is fixed to the shell flange, and the other is free to move inside the shell. This design accommodates large thermal expansion and allows the bundle to be removed for cleaning and maintenance.
U Tube Bundle – Both ends of each tube are bent into a U shape and inserted into a single tubesheet. Each tube expands independently, eliminating differential thermal stress between tubes and shell. U tube bundles are suitable for high thermal differential and high pressure service.
Tubes are joined to the tubesheet by expansion, welding, or a combination of expansion and seal welding. Expanded joints are suitable for low pressure and non-hazardous service. Welded joints are used for high pressure, hydrogen, and lethal service. Combined expanded and welded joints provide additional joint integrity for thermal cycling and high pressure applications. Full penetration welded joints are available for critical service.
The manufacturing process includes material inspection, tube cutting, tube bending for U tube bundles, tubesheet drilling, baffle fabrication, tie rod and spacer assembly, tube insertion, tube expansion, tube welding, stress relief when required, hydrostatic testing, non-destructive examination, cleaning, and packing. Tubesheets are drilled with CNC machines to achieve precise hole diameter, pitch, and ligament tolerances. Baffles are cut to the specified segmental or helical configuration and assembled with tie rods and spacer pipes to maintain uniform spacing. The completed tube bundle is dimensionally inspected and tested before shipment.
| Grade | C max | Mn max | P max | S max | Si max | Cr | Ni | Mo |
|---|---|---|---|---|---|---|---|---|
| TP304 | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 18.0–20.0 | 8.0–11.0 | — |
| TP304L | 0.035 | 2.00 | 0.045 | 0.030 | 0.75 | 18.0–20.0 | 8.0–12.0 | — |
| TP316 | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
| TP316L | 0.035 | 2.00 | 0.045 | 0.030 | 0.75 | 16.0–18.0 | 10.0–14.0 | 2.00–3.00 |
| TP321 | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 17.0–19.0 | 9.0–12.0 | — |
| TP347 | 0.08 | 2.00 | 0.045 | 0.030 | 0.75 | 17.0–19.0 | 9.0–13.0 | — |
| Grade | Tensile Strength min | Yield Strength min | Elongation min |
|---|---|---|---|
| TP304 | 515 MPa | 205 MPa | 35% |
| TP304L | 485 MPa | 170 MPa | 35% |
| TP316 | 515 MPa | 205 MPa | 35% |
| TP316L | 485 MPa | 170 MPa | 35% |
| TP321 | 515 MPa | 205 MPa | 35% |
| TP347 | 515 MPa | 205 MPa | 35% |
Hydrostatic Test – Performed on the assembled tube bundle or on individual tubes as specified.
Non-Destructive Examination – Eddy current testing, ultrasonic testing, liquid penetrant testing, radiographic testing, and helium leak testing as required.
Dimensional Inspection – Tube outside diameter, wall thickness, tube length, tube pitch, baffle spacing, tubesheet hole diameter, ligament width, and overall bundle dimensions.
Material Verification – Positive material identification and full traceability to mill certificates per EN 10204 Type 3.1 or 3.2.
Welding Qualification – Welding procedure specifications and procedure qualification records per ASME Section IX.
Surface Inspection – Visual examination for scratches, dents, corrosion, and weld defects.
Mill Test Certificates
ASME U Stamp Data Report when applicable
TEMA Datasheet
Dimensional Inspection Report
Hydrostatic Test Report
NDE Reports
WPS and PQR
Heat Treatment Charts
As-Built Drawing
Stainless steel tube bundles are used in shell and tube heat exchangers, condensers, reboilers, evaporators, economizers, air coolers, and waste heat recovery units. Typical industries include oil and gas, petrochemical, chemical, power generation, marine, pharmaceutical, food processing, and water treatment. The tube bundle can be supplied as a replacement part for existing heat exchangers or as a complete assembly with tubesheets and baffles.
Quantity
Tube material grade
Tube outside diameter, wall thickness, and length
Tube layout pattern and pitch
Number of tubes
Tubesheet dimensions and material
Baffle type, number, and spacing
Bundle type fixed floating or U tube
Design pressure and temperature
Connection type and flange standard
Required tests and documentation
Delivery period
