API 661 Air Cooler for Oil Refinery, ASME Section VIII Division 1

Yuhong Group Co., Ltd. supplies hydrocarbon processing equipment certified with the ASME U-Stamp. Our product portfolio includes:

• Air Coolers (Horizontal / Vertical, forced draft / induced draft)
• Shell and Tube Heat Exchangers & Condensers (TEMA, API 660)
• Pressure Vessels (per ASME Section VIII Division 1 & Division 2)
• Columns & Reactors
• Tube Bundles, Finned Tubes (G-type / L-type / Extruded), Header Boxes, Support Structures, Fan Assemblies

Air cooler is a type of heat exchanger that cools hot process streams using ambient air, with no water required.

Typical Applications (Refinery and Petrochemical Process Units):

• Crude Distillation Units (CDU) — Cooling of distillates, fuel oil residue and side distillate streams
• Hydrotreating Units (HDS, VGO HDT) — Cooling of reactor effluent containing H₂S и NH₄HS
• Hydrocracking Units — Cooling of high-pressure post-reactor streams (sour service)
• Fluid Catalytic Cracking (FCC) Units — Cooling of gas and heavy fractions, and condensation of light hydrocarbons
• Reforming Units (CCR, semi-regenerative) — Cooling of stabilized reformate and hydrogen-rich gas
• Gas Fractionation Units (GFU) — Cooling of ethane, propane and butane with partial condensation
• Compressor Stations for Underground Gas Storage & Main Gas Pipelines — Cooling of compressed gas (operating pressure up to 50 bar)
• Liquefied Natural Gas (LNG) Plants — Pre-cooling of natural gas prior to deep dehydration

• Design and construction: API Standard 661, Seventh Edition (2013, revised June 2018, reaffirmed July 2024)
• Pressure design: ASME Boiler and Pressure Vessel Code, Section VIII, Division 1 (wall thickness calculation for tube bundles, header covers, flange joints and headers)
• Materials: ASTM / ASME
• Welding: AWS D1.1 / ASME Sec. IX
• Sour service: NACE MR0175 / ISO 15156 (SSCC/HIC) — mandatory for hydrotreating and hydrocracking units (Reactor Effluent Air Coolers)
• Marking: ASME U-Stamp and CE-PED for European market
• Inspection: EN 10204 3.1 / 3.2 documentation for all load-bearing components

1. No water consumption: Cooling with ambient air eliminates water loss from evaporation and blowdown. No operating costs for water treatment. Capital expenditure is reduced as circulating water systems are not required.
2. Thermal performance for forced draft units: Forced draft design enables cooling of process streams with inlet temperatures ranging from 350°C to 400°C. Integrated diffusers keep the pressure drop across the tube bundle no more than 250–350 Pa.
3. Seismic and wind load design: Rated for maximum wind speed up to 160 km/h. Supports are engineered to withstand seismic intensity of Grade 9 per the MSK scale.
4. Compatibility with H₂S-containing media: Materials complying with NACE MR0175 / ISO 15156 are adopted when the partial pressure of H₂S is ≥ 0.05 psi or the mass fraction reaches 50 ppm. HIC testing of steel materials is mandatory.
5. Heat transfer performance under varying ambient temperatures (-40°C to +45°C): Warm air recirculation or steam heating is equipped for winter operation. The heat transfer coefficient at 38°C is approximately 40–80 W/(m²·K).

• Configuration: Forced draft or induced draft; horizontal tubes with cross-flow air
• Fins: Optional types (G / KL / extruded). Fin pitch adjustable (5–8 fins per inch)
• Header type: Plug-type for frequent mechanical tube cleaning; removable cover for chemical cleaning; manifold type
• Corrosion allowance: 0 to 6 mm, subject to medium corrosiveness
• Frame anti-corrosion coating: Hot-dip galvanizing (ISO 1461), epoxy coating (minimum 300 μm), final painting per RAL standards
• Low noise performance: Acoustic enclosures for fans and motors, low-turbulence blades; noise level controlled within 70–75 dB(A) at a distance of 10 meters