Advanced Test & Calibration Bench for Integrated Fuel Pump and Controller — to 6,200 RPM at 22 ± 0.2 kgf/cm².

A 100-litre stainless steel (SS-300 series, 3 mm wall) service tank feeds two separate gear pumps. The high-pressure pump is rated at 50 LPM at 50 kgf/cm², driven by a flameproof, foot-cum-flange mounted motor, and supplies test lines regulated by constant-pressure valves to 22 ± 0.2 kgf/cm² and 11 ± 0.2 kgf/cm². A second 50 LPM / 10 kgf/cm² pump serves an independent circulation and filtration loop.

A low-level sensor on the tank is linked to an interlock that automatically shuts down the pumps to prevent cavitation damage, and a removable lid allows internal cleaning and inspection.

• Multi-stage filtration: 16 µm pre-filter → 6 µm intermediate → 3 µm final, each β > 1000, with a differential-pressure gauge and a 3.5 bar bypass valve on every housing.
• Air separator: removes entrained gas bubbles before the unit to prevent pressure-regulation error or cavitation damage.
• Drain back pressure: a dome-regulated drain valve holds a constant 2 ± 0.2 kgf/cm² back pressure, simulating an engine fuel drain system.
• Temperature control: a plate heat exchanger handles 50 LPM of ATF against chilled water at 6 kgf/cm², holding the 15–40 °C operating range.

Low-pressure circuit

Designed for post-test drying. Compressed air enters through a moisture separator (drained periodically via a manual valve) and a fine particulate filter before being routed to the unit through a flexible hose, removing residual fuel from internal passages.

High-pressure circuit

Simulates bleed air supplied to temperature-sensing elements such as the TDK-Tp sensor. A high-precision regulator and fine filter feed a throttle valve that vents air to atmosphere in a controlled manner, simulating transient bleed events. Pressure is read on an analog gauge and logged via a high-accuracy transducer at the control panel.

Electrical drive & control

A high-speed motor coupled through a 1:4.32 gearbox drives the unit at speeds up to 6,200 RPM. A closed-loop, vector-controlled Variable Frequency Drive with encoder feedback resolves speed to within ±1 RPM, with the motor and gearbox mounted on vibration isolators inside the Motor Isolation Room.

The Command Room panel displays supply/drain pressures, pneumatic pressures, ATF and preservation-oil temperatures, electrical consumption and shaft speeds. A pulse duty-cycle generator outputs 27 VDC at 40 Hz (default 50% duty, front-panel adjustable) to actuate electro-mechanical valves on the unit, simulating ECU control signals. Safety systems include flameproof enclosures, an emergency-stop circuit, overpressure relief on both hydraulic and pneumatic lines, and the low-level fuel cut-off interlock.

Preservation & conditioning circuit

After testing, this circuit circulates heated protective oil through the unit's internal fuel passages to prevent corrosion, oxidation and residue build-up. It uses its own 100-litre stainless steel tank with a low-level sensor, a dedicated flameproof gear pump, and filtration identical to the main fuel system.

Oil is heated to 70 °C ± 2 °C for optimal coating and penetration into fine clearances. A bypass valve prevents overpressure on downstream blockage, and a relief valve diverts excess oil back to the tank. The circuit runs in static soak mode or continuous dynamic circulation mode.