High‑Pressure Feed Effluent Heat Exchanger for Hydrocracking | U‑Tube / Floating Head Design | Chrome‑Moly Steel Construction – ASME Code Fabrication for Refinery Service
Yuhong Group: Engineered Heat Exchangers for Critical Refinery Service
Yuhong Group Co., Ltd. designs and manufactures high‑performance thermal equipment for demanding industrial applications. Our core offerings include shell & tube heat exchangers, pressure vessels, and air coolers – with a special focus on high‑pressure, high‑temperature exchangers for hydroprocessing, hydrocracking, and refinery service.
Shown in the attached photographs is one of our recent project deliveries – a Feed Effluent Heat Exchanger (801CB) for a hydrocracking unit. This is a critical piece of equipment that recovers heat from the reactor effluent and preheats the feed stream, significantly improving process energy efficiency.
The feed effluent heat exchanger is one of the most demanding services in a hydrocracking or hydrotreating unit. It transfers heat between the hot reactor effluent (typically 350‑450°C) and the cooler feed stream entering the reactor. This duty requires:
High‑temperature capability – continuous service at 350‑450°C
High‑pressure rating – typically 100‑200 bar (10‑20 MPa)
Hydrogen service compatibility – materials resistant to hydrogen attack and H₂S corrosion
Thermal stress management – large temperature differences require U‑tube or floating head design
Based on the images, this exchanger exhibits:
Application: Hydrocracking unit feed/effluent service
Project: 801CB – core heat exchanger for the unit
Design type: U‑tube or floating head (to accommodate thermal expansion)
Material: Chrome‑molybdenum steel (F11/F22) with stainless steel or weld overlay cladding on hydrogen‑exposed surfaces
Construction: ASME Code compliant, U‑Stamp certified
Status: Successfully delivered to site
| Design Type | Advantage in Feed Effluent Service |
|---|---|
| U‑Tube | Single tubesheet – no differential thermal expansion issues. Ideal for high temperature differentials between feed and effluent. |
| Floating Head | Allows bundle removal for inspection; better access for cleaning if fouling is expected. |
The feed effluent exchanger typically uses a U‑tube design because the tube bundle can expand freely, and the single tubesheet eliminates the need for an expansion joint.
| Component | Typical Material | Role in Equipment Performance |
|---|---|---|
| U‑Bend Heat Exchanger Tubes | Chrome‑moly (F11/F22) or stainless steel | Carry the reactor effluent; exposed to high temperature and hydrogen. U‑bend allows thermal expansion. |
| Heat Exchanger Tubesheet | Chrome‑moly steel (F22) with stainless weld overlay | Anchors the U‑tubes; separates tube side (effluent) from shell side (feed). Overlay protects against hydrogen attack. |
| Shell | Chrome‑moly steel (F11/F22) | Contains the shell‑side feed stream; designed for high pressure (100‑200 bar). |
| Channel / Bonnet | Chrome‑moly steel (F22) | Distributes the feed/effluent streams; designed for high‑pressure closure. |
| Baffles | Chrome‑moly or stainless steel | Support U‑tubes; direct shell‑side flow for optimum heat transfer. |
| Fin Tube (optional) | Not typical in this service | Not used in liquid‑to‑liquid high‑pressure exchangers. |
| Impingement Plate | Stainless steel or alloy | Protects tube bundle inlet from high‑velocity effluent erosion. |
Chrome‑molybdenum (Cr‑Mo) steel construction: F11 (1.25Cr‑0.5Mo) or F22 (2.25Cr‑1Mo) provides high‑temperature strength and resistance to hydrogen attack (per API 941 / Nelson Curve).
Stainless steel weld overlay: On hydrogen‑exposed surfaces (tubesheet, channel internal faces) – prevents hydrogen diffusion and surface corrosion.
U‑tube design: Eliminates thermal stress between shell and tube bundle – critical when ΔT > 50°C.
ASME U‑Stamp certified: Full code compliance; materials traceable to ASME Section II.
Stringent NDE: 100% RT/UT on welds; MT/PT on all pressure‑retaining surfaces.
Hydrogen service design: Material selection per API 941; hardness controls to prevent hydrogen‑induced cracking (HIC).
In a typical hydrocracking unit, the feed effluent exchanger is the largest and most expensive heat exchanger in the process. Its failure can shut down the entire unit, costing millions per day.
Key design challenges:
High temperature differential: Feed enters at ~150‑200°C, effluent leaves the reactor at ~350‑450°C. The temperature difference across the exchanger is often >200°C – requiring U‑tube or floating head design.
High hydrogen partial pressure: Hydrogen at high temperature can cause:
High‑temperature hydrogen attack (HTHA) – methane formation at grain boundaries
Hydrogen‑induced cracking (HIC) – blistering in susceptible steels
Solution: Chrome‑moly steels (F11, F22) with proper heat treatment and hardness control.
Ammonium bisulfide corrosion: Corrosion in the effluent cooling section from NH₄HS formation.
Solution: Stainless steel or alloy cladding on tubesheets and channel internals.
Thermal cycling: Shutdowns and startups cause thermal fatigue.
Solution: Robust U‑tube design with adequate tube support and proper material selection.
| Condition | Recommended Material |
|---|---|
| Temperature < 350°C, H₂ partial pressure < 1 MPa | Carbon steel (SA516) – limited application |
| Temperature 350‑450°C, H₂ partial pressure 1‑5 MPa | F11 (1.25Cr‑0.5Mo) |
| Temperature 400‑500°C, H₂ partial pressure > 5 MPa | F22 (2.25Cr‑1Mo) or higher alloy |
| Temperature > 480°C | F91 or stainless steel / alloy |
Proven experience: Successfully delivered feed effluent exchangers (including 801CB as shown) for hydrocracking units.
Full engineering: Thermal design, mechanical design, and detailed fabrication – all in‑house.
Material expertise: Chrome‑moly steels, stainless steel clad plate, and nickel alloys – selection guided by API 941 and ASME Section VIII.
Complete documentation: Design reports, material certifications, NDE reports, and ASME data reports.
Project management: From order to delivery – including third‑party inspection (SGS, BV, TÜV).
If your existing exchanger needs replacement parts, we supply individual components without ordering a complete new exchanger:
U‑bend tube bundles – direct replacement for existing shells
Heat exchanger tubes – chrome‑moly (F11/F22), stainless steel (304/316L), nickel alloy – cut to length, bent, and end‑prepared
Heat exchanger tubesheet – drilled and grooved, with or without weld overlay
Baffles, tie rods, spacers – machined to your pattern
Channel covers, flanges – any facing type
Fin tubes – for air cooler retrofits
| Industry | Application | Material Selection |
|---|---|---|
| Petroleum refining (hydrocracking) | Feed/effluent exchangers – as shown | F11/F22 with stainless overlay |
| Hydrotreating | Reactor feed/effluent exchangers | F11/F22 or stainless steel |
| Chemical processing | High‑temperature synthesis exchangers | Chrome‑moly or stainless |
| Power generation | High‑pressure steam generators | F22 or F91 |
| Parameter | Detail |
|---|---|
| Project | Hydrocracking unit feed effluent exchanger |
| Unit tag | 801CB |
| Design type | U‑tube (typical for this service) |
| Material | Chrome‑molybdenum steel (F11/F22) with stainless overlay |
| Service | High‑temperature, high‑pressure hydrogen service |
| Compliance | ASME U‑Stamp, API 941 |
| Status | Successfully fabricated and delivered |
Every hydrocracking feed effluent exchanger we fabricate includes:
ASME U‑Stamp certification – design, materials, fabrication, and inspection
Material Test Certificates (MTC) per EN 10204 3.1 for all pressure‑retaining components
NDE reports – RT, UT, MT, PT as required by ASME
Heat treatment records – stress relief and PWHT (post‑weld heat treatment)
Hydrostatic test report – shell side and tube side
Positive Material Identification (PMI) – 100% verification
Third‑party inspection (SGS, BV, TÜV) – available at buyer's request
To quote a high‑pressure feed effluent exchanger like the one in your photographs, send the following to jimmy@steelseamlesspipe.com:
Process data sheet (flow rates, inlet/outlet temperatures, pressures)
Fluid composition (hydrogen content, H₂S, ammonia, etc.)
Project specifications (if available)
Required code compliance (ASME, API, etc.)
Our engineers will respond with a technical proposal, general arrangement drawing, and competitive price – typically within 72 hours.
