Gum formation during fuel storage can lead to deposits on induction system surfaces, intake valves, stems, and guides, affecting engine performance and efficiency. The Koehler Existent Gum Test Apparatus is designed to evaluate fuel stability by measuring the amount of gum formed when a 50mL sample is evaporated under precise conditions of temperature and airflow (for gasoline) or steam flow (for turbine fuel).
The apparatus consists of a high-temperature aluminum block evaporation bath, precision air/steam jets, and regulated flow and temperature control systems. It is available in multiple configurations to suit laboratory needs:
Model K33800 – Six-Unit Bath with Built-in Superheater
Equipped with a thermostatically controlled stainless steel superheating chamber and condensate trap, it delivers dried steam to the bath inlet for steam-jet testing of turbine fuels. Digital solid-state temperature control provides precise bath regulation with LED display for both setpoint and actual temperatures.
Model K33700 – Six-Unit Bath without Superheater
A robust, microprocessor-controlled aluminum block bath suitable for air-jet evaporation testing of motor and aviation gasoline samples. Includes built-in pressure regulator, flowmeter, and over-temperature safety circuitry.
Model K33780 / K33781 – Three-Unit Baths without Superheater
Compact versions designed for laboratories handling lower test volumes. All controls are housed within the bath cabinet, maintaining convenience and operational efficiency.
Each model features microprocessor PID temperature control, dual LED displays, and independent cartridge heating elements for precise temperature uniformity. Built-in pressure regulators and air/steam flowmeters ensure compliance with ASTM D381 test parameters. Optional RS232 communication software and advanced features (such as ramp-to-set programming) are available upon request.
