Professional Inline Hydraulic Flow Test Meter | 15-150 Lt/min | 3,700 PSI (250 Bar)

When a hydraulic machine experiences power loss or sluggish cycle times, a pressure gauge alone isn't enough. The only definitive way to safely and effectively test the health of pumps and motors is with a high-quality flow meter. This inline unit allows you to simulate load and measure efficiency with precision.

Technical Specifications:

• Flow Range: 15 - 150 Lt/min (Note: actual range as listed; photos may vary).
• Pressure Rating: Up to 3,700 PSI (250 Bar).
• Accuracy: ± 4%.
• Porting: 1" BSPP Female.
• Configuration: One-way flow (standard) or Optional Full Test Kit (includes Needle Valve, Test Tee, and Gauge).
• Dispatch: Please allow 2-3 business days to collate all Parts if selecting the Gauge/Adaptor option.

Why Flow Testing is Mandatory:

Hydraulic components are highly susceptible to wear from contaminants, dirt, cavitation, excessive heat and just lots of use. These issues will blow out internal tolerances, allowing oil to "slip" past surfaces.

This internal leakage or "slip" means that high pressures cannot be reached under load. Whether you are troubleshooting an excavator, skid steer, or industrial power unit, a flow test is the professional first step to identifying the specific point of failure or even potential / eminent failure.

Operational Procedures & Safety:

• Safety First: Always wear safety glasses and gloves. High-pressure oil injection can result in amputation and severe injury.
• Installation: Connect the meter to the pump’s pressure line. Ensure the exit hose returns oil safely to the tank. Flow must follow the direction of the arrow on the meter.
• Establishing a Baseline: Ensure the needle valve is fully open (Counter Clockwise) before starting. Record the flow at normal engine RPM with zero pressure or near zero pressure (e.g., 70 Lt/min @ 0 PSI).
• Load Simulation: Slowly close the needle valve to mimic a heavy load. Record flow readings at 500 PSI increments (500, 1000, 1500, etc.) until maximum operating pressure is reached.
• Interpreting Results: Gear pumps typically have a 20% bypass rate from new. If your flow drops more than 20% below your zero-pressure reading, the pump has significant internal wear and requires replacement.

Technician’s Advice

To test a hydraulic motor, the setup is similar, but you must fit a case drain hose back to the tank to measure internal leakage accurately. Always source and check the manufacturer’s specifications online before testing so you have a benchmark for the expected flow in Lt/min at specific pressures.
For Example. A pump that produces 70 Lt/min at zero pressure should still maintain at least 52 Lt/min at high pressure to be considered in good working condition.
Please note if testing parts of a hydraulic system and the oil return is not connected direct to tank but connected back into the system to eventually return to tank through the valve bank it is not uncommon to see between 200 and 500 psi of back pressure.

Example Of a Hydraulic Component Pressure Flow Performance Test.

Project: ____________________ | Date: ____ / ____ / 2026

Component (Pump/Motor): ____________________

Rated Flow (from Manual): __________ Lt/min @ __________ RPM

1. Preparation Checklist

• [ ] Safety glasses and gloves on.
• [ ] Needle valve fully open (anticlockwise) before starting.
• [ ] Return line connected securely back to the tank.
• [ ] Flow direction matches the arrow on the Flow Meter.
• [ ] Engine/Motor set to standard operating RPM.
  Ensure the same RPM is to Maintained throughout the test.

2. The Test Results

Use the table below to record the flow rate as you increase the resistance (pressure) using the needle valve.

Pressure (PSI)	Pressure (Bar)	Indicated Flow (Lt/min)	Notes
0 PSI	0 Bar		Base Flow (No Load)
500 PSI	35 Bar
1,000 PSI	70 Bar
1,500 PSI	100 Bar
2,000 PSI	140 Bar
2,500 PSI	175 Bar
3,000 PSI	210 Bar
3,500 PSI	240 Bar

3. Analysis (The "20% Rule")

• Formula:
  $$Baseline\ Flow \times 0.8 = Minimum\ Acceptable\ Flow$$
• Example: If your pump flows 70 Lt/min at 0 PSI, it should still flow at least 56 Lt/min at full working pressure.
• Verdict: If your "High Pressure" flow reading is more than 20% lower than your "0 PSI" reading, internal wear (slippage) is present.

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Technician’s Advice

Don't forget to monitor your oil temperature during the test. As oil gets hotter, it gets thinner (lower viscosity), which will increase "slippage" in a worn pump. If your machine works fine for the first 10 minutes but loses power as it warms up, perform this flow test once the oil has reached its normal operating temperature (usually 50°C to 60°C).

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