Standards:

Applications:

Product Information:

Free water can accelerate the oxidation process of fuel and promote the formation of acids, gums, and deposits, which are collectively referred to as fuel degradation products. Water mixed with acids in the fuel can corrode ferrous and non-ferrous metals, leading to rust and corrosion of fuel system components and infrastructure, damaging fuel tanks and engine parts. Fine or coarse emulsified undissolved water may also reduce the lifespan of injection systems.Modern fuel systems installed in passenger vehicles, heavy-duty trucks, or off-road applications require high or stable separation efficiency for all insoluble contaminants in the fuel to ensure extended service life. The oil-water separation test bench is primarily used to evaluate the oil-water separation efficiency of fuel filter products.

Design Basis

The test bench is designed in accordance with ISO 16332:2018 – “Method for evaluating the water separation efficiency of diesel engine fuel filters”, and it is used to test the water separation efficiency of fuel filters.

Test Items

Water Separation Efficiency

Flow vs. Pressure Drop Characteristics

Reference Standards

GB/T 786.1-2021 Fluid Power Systems and Components — Graphic Symbols and Circuit Diagrams, Part 1: Graphic Symbols

GB/T 3766-2015 Hydraulic Transmission — General Rules and Safety Requirements for Systems and Their Components

GB/T 7935-2005 Hydraulic Components — General Technical Conditions

GB/T 5226.1-2019 Safety of Machinery — Electrical Equipment of Machines, Part 1: General Requirements

GB/T 5923-2010 Test Methods for Diesel Engine Fuel Filters for Automobiles

Technical Features

The equipment adopts a closed-structure design. The test bench frame is made of industrial-grade high-strength aluminum profiles, which offer strong corrosion resistance, light weight, high strength, compact structure, attractive appearance, and ease of maintenance.

The operator panel and tabletop of the test bench are made of 304 stainless steel, while the protective doors and observation side panels are made of tempered glass, providing protection while allowing real-time observation of the test samples. The top of the operating area is also made of tempered glass and equipped with a light source to ensure adequate internal illumination.

The system features a user-friendly human-machine interface (HMI) with clear functions and simple operation. The test process is highly automated, displaying key filter test parameters such as pressure, differential pressure, flow rate, and temperature in real time, and allows one-button test start.

The test bench is equipped with comprehensive safety protection measures, including mechanical protection and electrical alarm interlock functions. It also features phase-sequence protection, electrical interlocks, over-temperature and over-pressure protection, and liquid level safety protection, with the ability to display corresponding alarm messages for fault troubleshooting.

Main Technical Specifications

Working Environmental Conditions

Ambient Temperature: 10℃ to 40℃

Ambient Humidity: 30% to 60% RH

Power Supply: AC 380V / 50Hz

Main Technical Specifications

No.	Technical Parameter	Specification	Remarks / Description
1	Test Fuel	Diesel 0#	-
2	Test Water	Purified Water	-
3	Test Temperature	23 ± 2 ℃	-
4	Fuel Flow Range	50–900 L/h	-
5	Water Flow Range	1.5–37.5 ml/min; 20–500 ml/min	-
6	System Pressure	1000 kPa	-
7	System Back Pressure	≥50 kPa	-
8	Product Differential Pressure	0–100 kPa	-
9	Orifice Plate Differential Pressure	0–250 kPa	-
10	Orifice Plate Flow Range	0.8–25 L/min	-
11	Test Fuel Tank Capacity	375 L	-
12	Auxiliary Fuel Tank Capacity	50 L	-
13	Test Water Tank Capacity	30 L	-
14	Online Laser Particle Analyzer	Measurement Range: 0.1–1000 μm Accuracy Error: ≤1% (D50 deviation, national standard sample) Testing Method: Installed in series on circulation pipeline, wet testing	-
15	Fully Automatic Karl Fischer Titrator	Automatic titration start, automatic sampler, manual or automatic reagent replacement	Optional
16	Heating Method	Silicone rubber electric heating	-
17	Cooling Method	Water-cooled	-
18	Main Test Bench Frame Material	Aluminum profiles, aluminum-plastic panels, stainless steel plates	-
19	Pipeline Material	304 Stainless Steel	-
20	Power Supply	AC 380V / 50Hz	-
21	Total Power	8 kW	-
22	Dimensions (L×W×H)	3200 × 1500 × 2000 mm	-
23	Weight	1000 kg	-

Schematic Diagram

Auxiliary Fuel Tank

Level Gauge

Throttle Valve

Solenoid Valve

Drain Valve

Auxiliary Circulation Pump

Pressure Sensor

Purification Filter

Absolute Water Separation Filter

Water Tank

Water Filter

Water Injection Pump

Check Valve

Water Filter

Overflow Valve

Water Injection Flow Meter

Three-Way Valve

Agitator / Stirring Device

Test Fuel Tank

Thermometer

Test Pump Unit

Heat Exchanger

Baseline Sampling Valve

Moisture Analyzer / Water Content Measurement Device

Flow Meter

Water Injection Device

Quick Coupling / Quick Connector

Orifice Differential Pressure Meter

Water Emulsification Device

DSD Measuring Device (Droplet Size Distribution)

Upstream Sampling Valve

Upstream Pressure Gauge

Test Product / Device Under Test

Product Differential Pressure Gauge

Downstream Sampling Valve

Fuel Filter

Three-Way Valve

Main Structure and Design Description

The test bench mainly consists of six parts: the test circulation system, water injection system, test auxiliary system, online laser particle analyzer, fully automatic Karl Fischer titrator, real-time temperature control system, electrical control system, and the test bench frame.

Test Circulation System

To ensure the proper flow velocity of fuel in the test pipelines, the test circuit is designed with two loops. Each loop is equipped with an independent flow meter, water injection device, water dispersion device, and temperature sensor. Pressure, differential pressure, and upstream/downstream sampling valves are

switched between the two loops via three-way switching valves. The layout of the system, component selection, and measurement accuracy meet the relevant standards for testing equipment.

Test Pump: A stainless steel gear pump with a rated pressure of 1.45 MPa and a rated flow of 33 L/min is used. This pump features a compact structure, smooth operation, and minimal flow and pressure pulsation.

Test Fuel Tank: Made of high-quality industrial-grade stainless steel, the tank has a total volume of 420 L and an effective volume of 375 L. The cone bottom angle is designed to be no greater than 90°, ensuring

that returned fuel disperses below the liquid surface. A level monitoring device is used to monitor the fuel level and ensure stable test operation. The tank is equipped with a mechanical agitator with adjustable speed. The impeller is of the propeller type, ensuring uniform water distribution in the fuel.

Flow Meter: The system uses stainless steel gear flow meters with a flow range of 0.3–50 L/min, capable of measuring fuel flows from 50–1500 L/h. Accuracy class is 0.5. and both the body and wetted materials are made of 316 stainless steel.

Pressure and Differential Pressure Instruments:

Pressure sensors: range 0–1 MPa, accuracy class 0.5.

Product differential pressure sensors: range 0–100 kPa, accuracy class 0.25.

Orifice differential pressure sensors: range 0–250 kPa, accuracy class 0.25.

Both pressure and differential pressure measurements use self-sealing quick-connect fittings for convenient installation.

Temperature Sensors: PT100 armored resistance thermometers with a temperature range of -50–200℃, accuracy class A.

Test Pipelines: Made of high-quality industrial sanitary-grade SUS304 stainless steel, with all fittings and layout designed to eliminate dead zones to maintain turbulent flow, minimizing areas where particles could settle. The flow velocity between the water injection device and the downstream sampling point is maintained at ≥0.75 m/s.

Absolute Water Separation Filter: Professionally designed and manufactured by our company based on years of laboratory data. It can maintain the baseline water content of diesel in the test system below 30 ppm, allowing rapid system purification. The filter also has automatic drainage and alert functions. When

the water level in the purification filter reaches the warning level, the system issues an alert, and after confirmation, the water is automatically discharged from the filter housing.

Water Injection System

Test Water Tank: The system uses bottled purified water in a smart tank system for convenience, hygiene, and to minimize external dust contamination. The bottom of the tank is stainless steel conical, with an angle not exceeding 90°.

Water Injection Device: Uses an adjustable ceramic metering pump combined with an injection needle set matched to the fuel flow, forming the water injection system. The injection amount and flow rate are adjustable to meet system requirements for water volume and droplet size. The needle replacement uses a handwheel device, allowing replacement without tools.

Water Dispersion Device: Uses a standard orifice plate and orifice seat made of stainless steel, with a structure that complies with standard requirements.

Water Injection Flow Meter: Used to monitor the water injection flow and, in conjunction with the ceramic pump, enables real-time control of the water injection rate. A micro-flow stainless steel cylindrical gear flow meter is selected, with flow measurement ranges of 0.4–40 mL/min and 2–1000 mL/min, and a pressure rating of 30 MPa. Both the housing and wetted parts are made of 316 stainless steel.

Water Injection Pipelines: Made of ferrule-type sanitary stainless steel pipes.

Test Auxiliary System

To ensure stable test operation, the test sampling structure adopts a continuous flow mode (i.e., the sampling valve remains open according to the sampling flow until the test is completed). Water-containing

fuel flows directly into the auxiliary fuel tank and is purified by the auxiliary circulation pump, then returned to the test fuel tank according to the flow rate. This design avoids interference with the fuel system during sampling and simultaneously collects residual test fuel, providing great convenience for equipment operation.

Online Laser Particle Analyzer

The online laser particle analyzer is used to calibrate and measure in real time the droplet size distribution of water generated by the water emulsification device (throttle orifice) after water injection. It is a key device installed in the high-efficiency fuel filter water removal capability test line, measuring the droplet size distribution produced by the water emulsification device. The detected water droplet size directly affects the evaluation of oil-water separation efficiency.

BT-Online4 Online Laser Particle Analyzer is a key device installed on the high-efficiency fuel filter water removal capability test line, used to measure the droplet size distribution of water generated by the water emulsification device. The measured droplet size is directly related to the evaluation of oil-water separation efficiency. Compared

with laboratory laser particle analyzers, the BT-Inline4 features accurate measurement, continuous monitoring, and long-term stable operation.

Performance Specifications

Item	Performance Specification	Item	Performance Specification
Measurement Range	0.1–1000 μm	Laser Source	Imported semiconductor laser
Repeatability	≤1% (Deviation of D50 of standard sample)	Operating System	Windows
Accuracy Error	≤1% (Deviation of D50 of standard sample)	Optical Detectors	68
Measurement Principle	Mie, Fraunhofer	Signal Interface	RS485
Test Method	Installed in series on circulation pipeline, wet testing	Accuracy Verification	Standard sample + BT-802PRO

Karl Fischer Titration System

The Karl Fischer titrator is used to measure the upstream and downstream water content of the test product. It is an essential auxiliary instrument required to complete the product testing. The measurement data directly affects the evaluation of the oil-water separation efficiency.

Technical Parameter

Category	Parameter	Specification
Voltage	Measurement Range	−2400 mV ~ +2400 mV
	Resolution	1.56 μV
	Measurement Accuracy	±0.5 mV (−2000 mV ~ +2000 mV)
	Input Resistance	≥ 1 × 10¹² Ω
	Zero Drift / Bias Current	≤ ±1 × 10⁻¹² A
Temperature	Sensor	Pt1000
	Measurement Range	−150℃ ~ +250℃
	Resolution	~0.002℃
	Measurement Accuracy	±0.4℃ (−20.0℃ ~ +150.0℃)
Polarization	Ipol DC
	Polarization Current	−200 μA ~ +200 μA, step 0.5 μA
	Measurement Range	−2400 mV ~ +2400 mV
	Measurement Accuracy	0.1 mV
	Upol DC
	Polarization Voltage	−2000 mV ~ +2000 mV, step 5 mV
	Measurement Range	−200 μA ~ +200 μA
	Measurement Accuracy	0.01 μA
Other Functions	Automatic Start Titration	Yes
	Manual or Automatic Reagent Replacement	Yes
	Titration Tube Resolution	100000
	Addition Unit Volume	2 mL, 5 mL, 10 mL, 20 mL or 50 mL
	Automatic Sampler with OMNIS Dis-Cover Design	Optional
	Automatic Sample Mass Import from Analytical Balance	Yes

Real-Time Temperature Control System

The test bench is equipped with heating and cooling devices to ensure the required temperature of the test system. The test temperature can be maintained at 23 ± 2℃, meeting the requirements of relevant standards.

Electrical Control System

The electrical control system mainly consists of hardware and software components. The system hardware uses a Siemens PLC combined with a touch-screen integrated controller. Internal electrical components are from Schneider or equivalent brands, effectively ensuring reliable equipment operation.

The operation software interface is simple and intuitive, capable of automatic operation based on set parameters, and can display the system working status in real time. The system supports both automatic and manual control modes. Once parameters are set, the test can be started with one-button operation. If the measured upstream water content does not meet test requirements, the water injection pump frequency can be manually adjusted for fine-tuning.

The control system is equipped with abnormal alarm and safety protection functions. When an abnormal condition occurs, the system displays common error causes to facilitate troubleshooting.

Test Bench Frame

The test bench frame is made of high-strength industrial aluminum profiles, with four industrial casters (each bearing up to 500 kg) with leveling feet, allowing both flexible movement and secure support.

The test panels and operation tabletop are made of stainless steel, with laser-etched markings that are clear, aesthetically pleasing, and permanent. The test bench incorporates transparent tempered glass safety protection, allowing easy observation of the test sample while effectively preventing fuel splashes from harming operators.

The top of the bench uses tempered glass combined with LED lighting to provide an energy-saving and environmentally friendly lighting solution, maximizing illumination for the test area.

Safety

The equipment features overpressure, over-temperature, overload, leakage, and liquid level protection, as well as abnormal condition alarms and self-protection functions to prevent accidents

and ensure safe operation. The program interface displays alarm information for timely troubleshooting. During operation, the system monitors test parameters in real time, and if any abnormal condition occurs, the system can automatically stop operation.

The equipment exterior is equipped with signal devices or warning signs to alert operators. Protective doors surround the bench, and electrical interlocks prevent accidents due to misuse, ensuring operator safety.

An emergency stop button is installed on the front operation panel to allow immediate shutdown in case of unexpected situations, minimizing damage and ensuring operator safety.

The bottom of the equipment features a removable drip tray to prevent environmental contamination caused by spills, leaks, or drips.