Close up of a Rotoflow turboexpander impeller

Engineering Solutions

All Rotoflow turbomachinery is built for a long and relatively maintenance-free operational life. We engineer components and conduct analyses that enhance safety, reliability, and efficiency—for every application requirement and major industry standard. Rotoflow quality dominates the industry.


Rotoflow’s specialized engineers utilize the study of rotordynamics to analyze a number of rotor-based structures, ensuring the reliable performance of Rotoflow turbomachinery within intended operational ranges.

Bearing Analysis & Design

All of the in-motion surfaces within a turboexpander bearing system need precise engineering to achieve optimal operational performance. Within the process of bearing analysis and design, Rotoflow engineers carefully study friction, lubrication, and system wear, identifying ways to reduce surface wear by adjusting surface properties and effectively utilizing surface lubricants.

Pressure-Containing Housing Design

Rotoflow pressure-containing housings are designed to the intent of the ASME Boiler and Pressure Vessel Code, ensuring safe, robust housings. Finite Element Analysis is used to ensure that housing designs meet stress and defection criteria under pressure, temperature, and external piping loads. Nondestructive testing of raw materials and manufacturing processes is used for quality control. All pressure-containing housings are pressure-tested at Rotoflow facilities prior to being put into service.

Gear & Gearbox Analysis

Rotoflow conducts extensive gear and gearbox analysis to ensure consistently high quality, ongoing product reliability, high plant availability, and extended service performance.

Impeller Design

Rotoflow impeller designs may be open (unshrouded) or closed (shrouded) for higher-efficiency applications. Impellers are made from aluminum, titanium, or stainless steel for optimum performance. Finite Element Analysis (FEA) is used to calculate impeller stresses under centrifugal, process torque, and thermal loads to ensure a robust design. Nondestructive testing of impeller raw material is used for quality control. Impellers may be overspeed spin-tested as a final confirmation of the design, material, and manufacturing process.

Impeller Frequency Analysis

Finite Element Analysis (FEA) is used to determine the natural frequencies and mode shapes of the impeller, ensuring a robust design. Destructive natural frequency modes are identified and avoidance with operating speeds is accomplished in the impeller design phase. Verification of actual impeller natural frequencies and mode shape is performed by experimentally measuring frequencies and shapes at Rotoflow facilities.

Static, Dynamic & Thermal Finite Element Analysis (FEA)

Turboexpander components moving at a high rate of speed can cause excessive vibration. Through effective engineering, Rotoflow works to prevent expander failure caused by component bending or component stiffness. Utilizing Finite Element Analysis (FEA), Rotoflow addresses structural issues in the engineering phase, ensuring that Rotoflow turboexpanders perform stably and effectively.

Computational Fluid Dynamics (CFD)

In the realm of fluid flow and its relationship to turboexpander performance, Rotoflow engineers utilize Computational Fluid Dynamics (CFD) to analyze the interactions between liquids, gases, and surfaces.

Advanced Material & Coating Application

Rotoflow material and coating applications are designed to withstand the wear and tear, corrosion, and extreme temperatures that come with cryogenic machinery, allowing materials to maintain their optimum operational characteristics.

Lube System & Seal Gas System Design

Rotoflow offers complete packaged lube oil and seal gas systems, with API614 part 2 and part 3 capabilities. Pressurized oil systems are available for seal gas recovery of high-value gasses like molecular hydrogen, helium, and carbon monoxide. Multiple layout options are available using standard modules to provide flexibility in plant design. Options are also available for expander process equipment including expander inlet valves, compressor recycle valves, and their associated instrumentation.

PLC Control System Design

Rotoflow is your exclusive source for Rotoflow control panel upgrades. Our control panel upgrade modernizes turboexpander supervision and shutdown by completely upgrading the relay board and other accessories to fully automated controllers including a Human Machine Interface (HMI) and machine monitoring system that diminishes system failures, avoiding long-term system outage due to inaccessible spare parts. The controllers are housed in a control cabinet suitable for the application and incorporate:

  • New updated microcontroller-based technology
  • State-of-the-art software and programming
  • HMI screens include permissive and trips, and minor trending capabilities
  • Open networks to other control systems, i.e., DCS
  • General-purpose machine monitoring systems
  • Lower downtime for troubleshooting
  • Parts available to support both hardware and software
  • Updated control panel drawings, i.e., wiring diagrams
  • Full field service support

Reverse Engineering

When non-Rotoflow parts are needed to complete a custom system design, a retrofit, or system repairs, Rotoflow engineers use our extensive knowledge of and experience with industry systems and parts to reverse-engineer parts from any number of manufacturers to OEM specifications.