Analysis of the causes of air leakage in the hydraulic valve HYDAC 3126253: moisture, contamination, and absence of adhesive agents

Introduction: symptoms of a leak occurrence

One of the most common technical problems in hydraulic systems is air leakage through blocked valves. In production in Ukraine, this often leads to increased energy costs, reduced accuracy of mechanism operation, and increased downtime time. This article discusses a case of air leakage in the HYDAC 3126253 valve, causing a malfunction in the hydraulic control system at a plant in Dnipropetrovsk region.

Component Overview

The HYDAC 3126253 valve is used for controlling fluid flow in hydraulic systems. It is installed in the hydraulic motor control system, where the pressure is maintained at 10–20 bar. The operating temperature of the fluid in the system is within the range of 20–60 °C, and the shaft speed does not exceed 1500 rpm. The valve complies with standards EN 12182 and ISO 4401.

Difference Detection

Technical personnel found that the valve did not meet the requirements during testing. An unexpected noise was heard by ear, and pressure fluctuations up to 3 bar were detected in the pressure sensors. Vibration measurements revealed explosions in the range of 10–20 microseconds, which exceeds the permissible range of 5–8 microseconds according to standard ISO 10816-3.. Moisture and contamination were found on the valve surface, indicating liquid leakage and dust accumulation.

Investigation of the causes of leakage

A "five why" analysis was performed to determine the cause of the leak. It was found that the air leak occurred due to moisture, contamination, and lack of adhesive agents.

Five Whys Analysis

1. Why is the valve leaking? — Due to air leakage.
2. Why does air leakage occur? — Due to moisture in the system.
3. Why is the system wet? — Increase in moisture due to the absence of liquid filtration.
4. Why is filtration not working? — Filter contamination.
5. Why is the filter contaminated? — Incorrect filter replacement and lack of scheduled maintenance.

Ishikawa Method

The Ishikawa method was used to determine possible causes of leakage. It was found that the main factors include:

• Moisture in the system
• Fluid Contamination
• Absence of adhesive means
• Incorrect Filter Replacement
• Lack of preventive maintenance

Root Causes

After analysis, three main causes that caused the air leak were identified:

1. Moisture in the system — Moisture has occurred due to the absence of liquid filtration, leading to valve contamination.
2. Fluid Contamination — Contamination occurred due to the absence of scheduled filter maintenance, leading to valve clogging.
3. Lack of adhesive means — Lack of adhesive means causes malfunction of the valve due to incorrect operation.

Correction Methods

To correct the case of air leakage in the HYDAC 3126253 valve, the following actions were performed:

1. Moisture Correction — Filter Replacement and Installation of Liquid Filtration System.
2. Contamination Correction — Performing scheduled filter maintenance.
3. Adhesive means — Use of adhesive means to ensure effective operation of the valve.

Quick diagnostic checklist for technical staff

The following is a check list for performing a quick diagnosis of air leak:

1. Check the system pressure and determine whether it exceeds the allowable level.
2. Perform vibration measurements and determine whether it exceeds the permissible limits.
3. Determine the moisture in the system using a hygrometer.
4. Check the condition of the filters and determine if they are contaminated.
5. Measure the temperature of the liquid and determine whether it exceeds the permissible limits.
6. Check for the presence of lubricants in the system.
7. Perform contamination level measurements of the fluid using a spectrometer.
8. Determine whether the scheduled maintenance of filters is carried out.
9. Check for air leakage using visual inspection.
10. Determine whether vibration control and air leakage check are performed.
11. Perform pressure measurements and determine whether it meets the requirements.
12. Determine whether humidity and liquid contamination control is performed.

Preventive strategy

To prevent the occurrence of air leakage in the HYDAC 3126253 valve, the following actions must be performed:

1. Install the liquid filtration system.
2. Perform scheduled maintenance of filters.
3. Use adhesive agents to ensure effective operation of the valve.
4. Perform vibration measurements and air leakage detection.
5. Perform measurements of moisture and liquid contamination.
6. Perform a visual inspection of the valve condition.
7. Perform temperature measurements of the liquid.
8. Perform pressure measurements in the system.
9. Perform measurements of the liquid contamination level.
10. Perform measurements of air flow.
11. Perform vibration measurements.
12. Perform moisture measurements.

Conclusion

The occurrence of air leakage in the HYDAC 3126253 valve may lead to serious consequences for production. Performing scheduled filter maintenance, installing a liquid filtration system, and using adhesive agents will help prevent leakage. For obtaining the necessary components for servicing and replacing the valve, visit UNITEC-D E-Catalog.

Information

Стандарти: EN 12182, ISO 4401, ISO 10816-3, DSTU 4218:2016

Certification: CE, UkrSEPRO

Quality Control: Vibration Measurement, Humidity, Temperature, Pressure

Обладнання: Вологомір, спектрометр, вимірювач вібрації, манометр

Засоби для відновлення: Ліпкі засоби, фільтри, компоненти для ремонту

Table: Permissible Parameters

Sources

• EN 12182:2018 — Standards for Hydraulic Valves
• ISO 4401:2019 — Standards for Hydraulic Systems
• ISO 10816-3:2015 — Vibration Measurement in Mechanical Systems
• DSTU 4218:2016 — State Standard of Ukraine for Moisture Measurement
• Air Leak Analysis Guidance for Hydraulic Systems
• Hydraulic Valve Repair Manual HYDAC