1. Problem description and scope

This is a manual for diagnosing excessive oscillations in rotating equipment including turbines, compressors, electric motors and pumps. Excessive vibration is considered critical because it can cause damage to bearings, vibrating assemblies, and the mechanical structure. The problem can occur in a variety of production conditions, including load changes, lack of lubrication, or exceptional operating conditions.

2. Preventive measures

Use personal protective equipment (PPE):

• Gloves
• Glasses
• Pants with steel inserts
• Cascade

Perform lockout/tagout when measuring or repairing equipment with stored energy. All mechanical energy sources are disconnected before vibration measurement.

3. Necessary diagnostic tools

4. Check before starting diagnostics

5. Systematic diagnostic scheme

1. Symptom: Excessive vibration
   1. Measure the vibration amplitude (mm/s) on the bearings and housing
   2. If the amplitude exceeds 4.5 mm/s, perform the diagnostic scheme
2. Symptom: Irregular oscillations
   1. Use spectrograph to analyze frequencies
   2. If the vibration frequency corresponds to 1x rotation, there is a possible lack of balance
3. Symptom: Vibration at different loads
   1. Measure vibration at different speeds
   2. If the vibration increases, there may be a lack of balance or a difference from the center
4. Symptom: Vibration when working with high load
   1. Check the condition of the bearings
   2. If there is damage, the bearing may be defective
5. Symptom: Vibration when reducing speed
   1. Measure vibration at different speeds
   2. If the vibration decreases, resonance is possible

6. Matrix of differences of causes

7. Analysis of root causes

7.1. Mass unevenness (embalsage)

Embalsage occurs due to the uneven distribution of mass on the rotary assembly. This results in a vibration at a frequency of 1x rotation. If this is not corrected, bearing damage, shaft wear, or housing damage may occur.

7.2. Incorrect centering

Incorrect centering occurs due to the difference in the centers of rotation of the axes. This results in a 2x or 4x frequency vibration. If not corrected, crown damage, axle chipping, or body chipping occurs.

7.3. Bearing defect

Bearing failure can be caused by damage, wear, or improper installation. The vibration occurs at a frequency of 1x. If not corrected, damage to the shaft, housing or other components will occur.

7.4. Resonance

Resonance occurs when the frequency of vibration matches the natural frequency of the system. Vibration increases at certain speeds. If not corrected, damage to the shaft, housing or other components will occur.

8. Step-by-step correction procedures

8.1. Correction of mass unevenness (embalsage)

1. Measure the vibration amplitude at 1x frequency
2. Perform balancing using a balancing state
3. Check the vibration amplitude after balancing
4. If the amplitude is below 4.5 mm/s, it is solved

8.2. Correcting incorrect centering

1. Measure the vibration amplitude at 2x or 4x frequency
2. Center using templates or screws
3. Check the vibration amplitude after centrifugation
4. If the amplitude is below 4.5 mm/s, it is solved

8.3. Correction of a bearing defect

1. Measure the vibration amplitude at 1x frequency
2. Measure the temperature of the bearing
3. Replace the bearing
4. Check the vibration amplitude after replacement
5. If the amplitude is below 4.5 mm/s, it is solved

8.4. Correction of resonance

1. Measure the vibration amplitude at different speeds
2. Determine the frequency at which the vibration increases
3. Change the rotation speed or install a damper
4. Check the vibration amplitude after the changes
5. If the amplitude is below 4.5 mm/s, it is solved

9. Prevention methods

10. Spare parts and components

For spare parts visit: https://www.unitecd.com/e-catalog/

11. Links

• DSTU 3028-95: Actions with electrical equipment
• ISO 10816-1: Vibration measurement
• EN 60034-1: Operating conditions of electric motors
• CE, UkrSEPRO: Product certification
• UNITEC-D Technical Guides: Service Manual

1. Description of the problem and scope

This guide is intended to identify and resolve the causes of low flow or no discharge in a centrifugal pump. Problems can arise in various types of equipment: food production, chemical industry, energy, transport. Importance Column: Critical because low flow can lead to component wear, loss of efficiency, and even breakdowns.

2. Safety precautions

Use PPE, including gloves, headgear, and protective pants. Perform a lockout/tagout procedure before accessing equipment to prevent unintended starts. Turn off the power and release any residual pressure in the system. A dangerous situation can occur if there is no release and high pressure.

3. Necessary diagnostic tools

4. Initial assessment and checklist

5. Systematic diagnostic flow

1. Symptom: No flow
   1. Check inlet and outlet pressure.
   2. If the inlet pressure is less than 0.3 bar, check the suction system.
   3. If the exhaust pressure is higher, check for air in the system.
2. Symptom: Low Flow
   1. Measure inlet and outlet temperatures.
   2. If the temperature exceeds 60°C, check for cavitation.
   3. If the temperature is normal, check the vibration of the pump.
3. Symptom: Uneven flow
   1. Use a thermal camera to analyze the temperature profile.
   2. If the temperature differs by more than 10°C, check for cavitation.
   3. If the temperature is normal, check the vibration deviations.

6. Matrix of causes of defects

7. Analysis of the causes of defects

7.1 Cavitation

Reason: Cavitation occurs when the pressure in the inlet stream drops below the boiling point of the liquid, resulting in the formation of voids. This leads to domestic disc wear, explosions, noise and uneven flow.

Confirmation: Measure inlet and outlet pressure. If the inlet pressure is less than 0.3 bar, cavitation occurs. Use a thermal camera to detect overheating.

Effect: Cavitation causes wear, explosions, noise, and reduced efficiency.

7.2 Worn domestic disc

Reason: The domestic disk wears out due to long-term operation or improper use. This leads to reduced flow, explosions and increased vibration.

Confirmation: Measure the vibration. If the vibration is more than 4.5 mm/s, the domestic disc may be worn. Measure the outlet pressure.

Impact: A worn domestic disc leads to reduced flow, explosions, increased energy costs.

7.3 Air in the system

Cause: Air can enter the system due to incorrect valves or leaks. This results in lack of flow and uneven distribution.

Confirmation: Check for air in the system. Use a pressure sensor to detect changes in pressure.

Impact: Air in the system results in no flow, uneven distribution and reduced efficiency.

7.4 Incorrect system configuration

Reason: Improper system setup can result in low flow or no output. This is due to incorrect pressure, flow or altitude settings.

Confirmation: Use the thermal camera to analyze the temperature profile. Measure vibration and pressure.

Impact: Improper system setup leads to low flow, explosions, and increased energy costs.

8. Step by step solution procedure

8.1 Cavitation

1. Measure the inlet and outlet pressures.
2. If the inlet pressure is less than 0.3 bar, clean the suction system.
3. Set the inlet pressure above 0.3 bar.
4. Check the vibration and temperature.
5. If the vibration is more than 4.5 mm/s, replace the domestic disc.

8.2 Worn domestic disc

1. Measure vibration and exhaust pressure.
2. If the vibration is more than 4.5 mm/s, replace the domestic disc.
3. Install a new domestic disc with the sampling specifications.
4. Check exhaust pressure and vibration.
5. Replace the domestic disk if the flow does not return to normal.

8.3 Air in the system

1. Check for air in the system.
2. Use a pressure sensor to detect changes in pressure.
3. Bleed the air through the valve.
4. Check the inlet and outlet pressures.
5. If the outlet pressure is higher, bleed the air.

8.4 Incorrect system configuration

1. Use a thermal camera to analyze the temperature profile.
2. Measure vibration and pressure.
3. Set the pressure and flow parameters according to the specifications.
4. Check for vibration and pressure.
5. Perform a system adjustment if the flow does not return to normal.

9. Prevention networks

10. Spare parts and components

Learn more about parts: https://www.unitecd.com/e-catalog/

11. Links

• DSTU 3066-95: Technical conditions for centrifugal pumps
• EN 12723: Instructions for operation and maintenance of pumps
• ISO 9906: Rules of operation and maintenance of pumps
• UNITEC-D technical instructions
• Original manufacturer's instructions

1. Problem description and scope

This guide is intended for diagnosing and solving problems associated with water hammer in systems with hydraulic automatic valves. Water hammer occurs due to a sudden change in pressure and speed of fluid movement in pipelines, which can lead to explosions, damage to pipelines, valves, pumps and other equipment. The problem can arise in systems of the food industry, energy, chemical industry, as well as in cooling and air conditioning systems. The importance of this issue is classified as critical, as water hammer can result in the failure of valuable equipment and hazardous conditions for personnel.

2. Safety and Warnings

Use personal protective equipment (PPE): glasses, gloves, means to protect against noise and higher pressure.
Perform lockout/tagout procedures: be sure to turn off power and system pressure before performing any diagnostic actions.
Be careful when working with high pressure: high pressure can cause an explosion or leakage of liquid, which requires additional protection.
Check for stored energy: in systems using springs or electromagnets, storing energy can lead to unpredictable movements.

3. Necessary diagnostic tools

4. The first inspection with filling out the report

5. Systematic diagnostic scheme

1. Symptom: Unpredictable noise and explosions during valve operation
   1. Check: Fluid leakage or vibration
      1. If vibration is high: Check valve closing speed
         1. If closing speed is higher than 1.5 m/s: Check valve parameters and selection damper
            1. If the damper does not match: Select the correct damper
2. Symptom: High system pressure
   1. Check: Leaks or improper connections
      1. If leakage is found: Check valve and piping for tightness
3. Symptom: Unstable operation of the valve
   1. Check: Presence of clogging or malfunction in the system
      1. If clogging is detected: Clean the pipeline and valve

6. Matrix of causes of malfunctions

7. Analysis of the reasons for each malfunction

7.1 Closing speed > 1.5 m/s

A valve closing speed greater than 1.5 m/s may result in water hammer, causing explosions and pipeline damage. This is caused by an insufficient closing speed of the valve, which does not meet the recommended parameters.

How to check: Measure the closing speed of the valve with a flow rate tester. If the value is higher than 1.5 m/s, this indicates a problem.

Consequences: Explosions, valve, pipeline and pump damage.

7.2 Wrong choice of damper

Incorrect damper selection can result in insufficient vibration reduction resulting in water hammer. The damper must be selected taking into account the flow rate and pressure in the system.

How to check: Check the damper parameters and compare with the recommended values.

Consequences: Unstable operation of the valve, explosions, pipeline damage.

7.3 Low level of pipeline diameter

A small pipe diameter can lead to high flow velocities that cause water hammer. This occurs due to the insufficient size of the pipeline for the working volume.

How to check: Measure the diameter of the pipeline and compare with the design values.

Consequences: Explosions, pipeline damage, reduction of system efficiency.

8. Step-by-step solution methods

8.1 Correction of valve closing speed

1. Measure the valve closing speed
2. If the speed > 1.5 m/s, install a control system
3. Set the closing speed to 1.2 m/s
4. Check for explosions

8.2 Choosing the right damper

1. Determine the flow rate and pressure in the system
2. Choose a damper according to the recommended parameters
3. Install the damper in the system
4. Check for explosions

8.3 Change in pipeline diameter

1. Measure the diameter of the pipeline
2. If the diameter is smaller than the design, replace the pipeline
3. Install a new pipe
4. Check for explosions

9. Preventive measures

10. Spare parts and components

To order components, please follow the link: https://www.unitecd.com/e-catalog/

11. Links

Additionally use:

• Standards: EN 12238, ISO 5199, DSTU 4185-2018
• Original manufacturers: Catalogs of manufacturers of valves and pipelines
• Specialized guides: UNITEC-D additional materials on hydraulic systems

1. Problem description and scope

This tutorial is intended to solve problems related to insufficient capacity of the hydrocooling system in industrial installations. Problems can occur in any industry that uses cooling systems, including airfields, food processing plants, chemical plants, and energy facilities. The threat is classified as critical because insufficient cooling flow can cause the equipment to overheat and fail.

2. Safety precautions

Ensuring power cut and blocking of mechanical working parts before performing any actions.

Use special equipment to protect against electric current, moisture and high pressure.

Before starting work, check the presence of residual energy in the system.

3. Necessary diagnostic tools

4. First assessment

5. Systematic diagnosis

1. Symptom: The cooling system does not remove enough heat.
   1. Measure the temperature at the inlet and outlet of the system.
   2. If the difference is more than 10°C, check the cooling flow.
2. Symptom: Temperature increase in key nodes.
   1. Use thermography to detect high temperature areas.
   2. Check for dirt build-up.
3. Symptom: Pressure mismatch in the system.
   1. Measure the pressure at the inlet and outlet.
   2. If the pressure is higher than 80% of the nominal, check the filters.

6. Matrix of causes of malfunctions

7. Analysis of root causes

7.1 Contamination of filters

Contamination of the filters can reduce the cooling flow. This occurs due to dust accumulation, clogging or high levels of pollution. If the filters are not cleaned regularly, they can cause the system to overheat and increase energy consumption.

7.2 Contamination of the heat exchanger

Contamination of the heat exchanger reduces the efficiency of heat exchange. This can be caused by deposits, moisture or high levels of pollution. Improper ventilation or high humidity can damage the heat exchanger.

7.3 Refrigerant leak

Refrigerant leakage can occur due to damage to pipelines, filters or components. This leads to a decrease in the efficiency of the cooling system and can lead to overheating of the equipment. Re-introduction of chladon without diagnosis can cause a repeated leak.

8. Step-by-step decision procedures

8.1 Removal of contamination of filters

1. Turn off the system and disconnect the electrical power.
2. Open the filters and remove the dirt.
3. Check inlet and outlet pressure to ensure correct flow.

8.2 Cleaning the heat exchanger

1. Use thin fluids to clean the heat exchanger.
2. Check for moisture and high levels of contamination.
3. Measure the inlet and outlet temperatures again.

8.3 Recovery of the khladon solution

1. Turn off the system and disconnect the electrical power.
2. Measure pressure and temperature.
3. Add the appropriate amount of refrigerant and check the pressure.

9. Preventive measures

10. Spare parts and components

For more information on spare parts, please visit: https://www.unitecd.com/e-catalog/

11. Links

• DSTU 4787:2017 – Requirements for maintenance of industrial equipment
• EN 13790:2016 – Requirements for cooling systems
• ISO 14617:2019 – Diagnostics of industrial systems
• UNITEC-D Maintenance Manual