Yuhong Group has expanded its production bay for API 660 kettle type reboilers, responding to rising distillation enquiries from refinery and petrochemical EPC contractors. The line now builds shells from 600 to 2,600 mm diameter, with unit weights up to 45 tonnes.
This briefing sets out the pressure and temperature range that is standard for an API 660 kettle reboiler, the ASME limits that bound it, and the point at which a project review becomes mandatory.
Kettle reboilers sit at the heart of distillation columns: the duty determines product purity, steam consumption and column stability. A reboiler undersized by even a few percent forces operators to raise steam pressure permanently. That is why project teams specify API 660 together with TEMA class R requirements rather than buying on price alone.
| Parameter | Standard Range | Project-Specific Range (by engineering review) |
|---|---|---|
| Design pressure | up to 100 bar | Project review required; above 100 bar |
| Design temperature | -29 to 350 C | Project review required; outside -29 to 350 C |
| Heat transfer area | 10 to 900 m2 | up to 1,500 m2 |
| Bundle type | removable U tube | fixed or floating head |
The standard range reflects our production record on refinery and petrochemical kettle reboiler projects, bounded by ASME Section VIII Division 1 allowable stress limits for SA516 Gr.70 and SA266 Gr.2. Ratings above it are not catalogue values: they are quoted only after a project-specific review of material, fatigue, nozzle reinforcement and inspection scope.
API 660 governs geometry, tolerances, impact testing and documentation for exchangers in petroleum service. For a kettle reboiler the practical differences show up in three places: an oversized vapour disengagement space that prevents entrainment into the column, a weir height calculated for the required residence time, and a bundle that can be withdrawn for mechanical cleaning without cutting pipework. Shell thickness follows ASME UG-27 with joint efficiency per UW-12 and PWHT per UCS-56.
Engineering teams issue a thermal design sheet with every quotation, so procurement can compare duty, approach temperature, fouling factor and pressure drop line by line. Third party inspection by BV, TUV or SGS is arranged at the client's nominated scope.
Standard lead time for a single API 660 kettle reboiler is 45 to 70 working days from approved drawings, with expedited slots available for turnaround and shutdown projects. Each unit ships with a documentation package containing the design report, material certificates, welding procedure and qualification records, NDT reports, hydrotest certificate and as-built drawing set, packed in fumigated seaworthy cases or nitrogen purged where internal cleanliness is critical.
Standard builds cover design pressures up to 100 bar(g) and design temperatures of -29 to 350 C. Higher pressure or temperature is not a catalogue rating; each case is quoted only after a project-specific engineering review covering material, fatigue and inspection scope.
Carbon steel SA516 Gr.70 shells with SA179 or SA213 TP304L/TP316L tubes and SA266 Gr.2 or SA182 F11 tubesheets form the standard build, with selection following the process fluid, chloride level and design temperature. Monel 400, C70600 and duplex S31803 bundles are supplied for corrosive or chloride bearing duties.
Each unit is hydrotested at 1.5 times design pressure, with NDT by RT, UT, PT and MT and full EN 10204 3.1 material traceability. Third party inspection by BV, TUV or SGS can be witnessed at the client's nominated scope.
Above 100 bar(g) the limiting factor is usually nozzle reinforcement, flange rating and tubesheet thickness rather than shell thickness, so the constraint sits in the connections, not the pressure envelope. Each case needs a fatigue assessment before any rating is offered.
