Yuhong Group Co., Ltd. is an ASME-certified manufacturer of shell and tube heat exchangers, pressure vessels, and air coolers, serving clients worldwide with equipment built to ASME Section VIII Division 1 and TEMA standards. Our product portfolio includes floating head, U-tube, and fixed tubesheet exchangers, as well as replacement tube bundles, U-tubes, heat exchanger tubes, finned tubes, and critical components such as tubesheets, baffles, and channel heads.
The AES floating head shell and tube heat exchanger is a TEMA-designated unit featuring a removable channel cover (A), a single-pass shell (E), and a floating head with backing device (S). This configuration is the industry standard for refinery and process services where thermal expansion management, mechanical cleanability, and bundle removability are essential. The design allows the tube bundle to expand and contract independently of the shell, eliminating thermal stress while enabling full bundle withdrawal for inspection and cleaning without disturbing shell-side piping.
| Component | Material / Standard | Specification Details |
|---|---|---|
| Shell | ASME SA516 Gr.70 | Carbon steel pressure vessel plate; tensile strength 70–90 ksi (485–620 MPa); yield strength 38 ksi (262 MPa) min |
| Stationary & Floating Tubesheets | ASME SA266 Gr.2 (Normalized) | Carbon steel forging for pressure vessel components; normalized heat treatment provides improved and uniform mechanical properties for thermal cycling reliability |
| Tube Bundle | Custom (SA179, SA213, etc.) | Configurable per process requirements; straight tube, removable bundle design |
| Baffle System | SA516 Gr.70 | Single or double segmental; baffle cut 25–35% for optimized shell-side flow |
| Channel & Cover | SA516 Gr.70 or SA105 | Bolted removable cover for tube-side access and maintenance |
| Floating Head Seal | Graphite or PTFE packing gland | Leakage rate <0.1%; graphite for >300°C, PTFE for corrosive media |
All AES heat exchangers undergo rigorous inspection and testing in accordance with ASME Section VIII Division 1 and TEMA standards.
| Test Type | Description |
|---|---|
| Hydrostatic Test | Shell side and tube side tested separately at pressures exceeding design limits per ASME VIII Div.1; minimum metal temperature 20°C; pressure maintained for minimum 1 hour |
| Pneumatic Test | Applied where hydrostatic testing is not feasible due to process or installation constraints |
| Non-Destructive Testing (NDT) | Radiographic (RT), Ultrasonic (UT), Dye Penetrant (PT), and Magnetic Particle (MT) inspection of welds and base metal |
| Leak Testing | Verification of tube-to-tubesheet joints (expanded and welded) |
| Dimensional Inspection | Tube hole spacing, diameter tolerance, verticality, and surface finish verified per TEMA requirements |
AES floating head exchangers are specified for demanding process conditions across multiple industries:
Petroleum Refining – crude oil preheat trains, atmospheric/vacuum distillation overhead condensers, reboilers, product coolers (diesel, vacuum gas oil), amine regenerator reboilers, and lubricating oil / seal oil coolers
Petrochemical & Chemical Processing – reactor effluent cooling, distillation column reboilers and condensers, corrosive fluid heat exchange, polymer solution cooling, and solvent recovery
Gas Processing – cooling and heating of process gases, special gas aftercoolers and intercoolers
Power Industry – high-pressure feedwater heaters requiring periodic descaling
Thermal Stress Management – The floating head design accommodates differential thermal expansion between shell and tubes. When temperature differential (ΔT) between shell and tube sides exceeds 80°C, floating head displacement must be verified during design. Operating temperature range: –50°C to +400°C (extended with special materials).
Maintenance & Cleaning – The removable bundle design allows the entire tube bundle to be withdrawn from the shell, enabling thorough mechanical cleaning of both tube outer surfaces and shell interior. This significantly reduces maintenance downtime in fouling services such as crude oil, slurries, and heavy hydrocarbons.
Design Flexibility – Shell diameters from DN150 to DN1200 (larger shells require reinforcement); heat transfer area up to 1500 m² (1200 m² maximum for tubes ≤12m per TEMA). Tube outer diameters: 19.05 mm (3/4") or 25.4 mm (1"); tube layout angles: 30°, 60°, or 90°. Design pressure: 0.6–6.4 MPa (6–64 bar) standard, with high-pressure models available upon request.
Custom Engineering Services – We provide full customization including material selection (carbon steel, alloy steel, stainless steels 304/316L, duplex, and special alloys), nozzle orientation and flange ratings (ANSI 150–900 / DIN PN16–40), baffle configuration, and tube pass arrangements. Thermal design is performed using HTRI software to ensure optimized performance for each specific duty.
Q: What does the "AES" designation mean?
A: "A" indicates a channel with removable cover for tube-side access; "E" indicates a single-pass shell; "S" indicates a floating head with backing device (rear head). This is a TEMA-standard classification system used globally for shell and tube heat exchanger specification.
Q: Why choose an AES floating head over a fixed tubesheet or U-tube design?
A: AES floating head exchangers are specified when both the shell side and tube side require mechanical cleaning, when significant thermal expansion is expected, and when the tube bundle must be removable for maintenance. Unlike fixed tubesheet designs, the AES allows bundle withdrawal; unlike U-tube designs, it permits straight tubes and internal cleaning of individual tubes.
Q: What is the difference between TEMA Class R, C, and B?
A: TEMA Class R is for refinery and severe service; Class C is for general commercial and chemical service; Class B is for chemical process service. Each class specifies different minimum wall thicknesses, tolerances, and inspection requirements.
Q: How is the tubesheet manufactured and inspected?
A: SA266 Gr.2 tubesheets are forged and normalized, then machined per customer drawings. Unmachined surfaces are sufficiently free of scale to permit inspection; machining is performed after heat treatment; welding repair is not permitted. NDT includes 100% PT, UT, and PMI verification.
Q: What design codes can you comply with?
A: All units are designed and fabricated to ASME Section VIII Division 1 with U-Stamp certification, and TEMA standards (Class R, C, or B as required).
For technical specifications, custom design inquiries, or replacement bundle requirements, contact Yuhong Group Co., Ltd. at vladimir@steelseamlesspipe.com.
