Why Is Factory Compressed Air Pressure Dropping? Causes and Testing Tools Malaysia
Meta Description: Discover common causes of compressed-air pressure loss and learn how Malaysian factories can investigate leaks, blocked filters, pipe restrictions and compressor loading.
A compressed-air system may show normal pressure near the compressor but lower pressure at production equipment.
This pressure loss can cause slow pneumatic tools, unstable machinery, production defects and longer compressor operating time.
The cause may involve air leakage, blocked filters, undersized pipes, excessive demand, faulty drains or a compressor that cannot meet the required airflow.
Common Causes of Compressed-Air Pressure Drop
The most common causes include:
Air leakage
Blocked filters
Undersized pipes
Long or poorly arranged pipework
Excessive air demand
Partially closed valves
Failed regulator
Restricted dryer or separator
Faulty condensate drain
Insufficient compressor capacity
Pressure vs Airflow
Pressure and airflow are related, but they are not the same.
Pressure
Describes the force of compressed air within the system.
Airflow
Describes the quantity of air delivered over time.
A system may show acceptable pressure when no equipment is operating but experience a major pressure drop when production demand increases.
Measurements should therefore be taken under actual operating conditions.
1. Compressed-Air Leakage
Air leakage is one of the most common causes of:
Pressure loss
Longer compressor operating time
Higher energy consumption
Reduced production performance
Unnecessary compressor loading
Common leakage points include:
Quick couplings
Hose connections
Valves
Regulators
Filters
Drain points
Pipe joints
Pneumatic cylinders
Flexible hoses
Production machinery
How to Find Air Leaks
Large leaks may be audible.
Smaller leaks can be difficult to hear in a noisy factory.
Possible detection methods include:
Listening during production shutdown
Approved leak-detection solution
Ultrasonic leak detector
Pressure-decay test
Compressor run-time observation
An ultrasonic leak detector can help locate high-frequency sound produced by escaping compressed air.
2. Blocked Filters
Compressed-air filters remove particles, oil and moisture.
As a filter becomes loaded, pressure loss across it may increase.
Check:
Filter differential-pressure indicator
Service interval
Internal element condition
Contamination
Water or oil accumulation
Measure pressure before and after the filter under actual airflow demand.
3. Restricted Air Dryer
An air dryer may create excessive pressure loss because of:
Blocked filters
Internal contamination
Incorrect valve operation
Overloading
Icing or abnormal temperature
Maintenance problems
Compare inlet and outlet pressure under the same airflow condition.
4. Undersized Pipework
A pipe that is too small for the required airflow can create excessive pressure loss.
Possible signs include:
Acceptable pressure near the compressor
Low pressure at distant equipment
Larger pressure drop during peak production
Reduced pneumatic-machine performance
Compressor pressure setting continually increased
Increasing compressor pressure may hide the symptom while increasing energy use.
5. Long Pipe Runs and Excessive Bends
Pressure loss increases with:
Pipe length
Small diameter
High airflow
Rough internal surface
Numerous elbows
Restrictions
Poorly selected fittings
Inspect the complete route between the compressor and problem equipment.
6. Partially Closed Valve
A valve may be:
Partially closed
Damaged
Incorrectly positioned
Internally obstructed
Affected by actuator failure
Check valve position and condition before assuming the compressor is undersized.
7. Faulty Pressure Regulator
A regulator can restrict airflow or produce unstable downstream pressure.
Possible signs include:
Pressure drops only after one regulator
Output pressure fluctuates
Downstream equipment is affected while upstream pressure remains normal
Adjustment does not produce the expected response
Measure both inlet and outlet pressure while the connected equipment is operating.
8. Excessive Air Demand
Compressed-air demand may increase because of:
New machinery
Additional production lines
More pneumatic tools
Larger nozzles
Continuous blowing
Increased cycle rate
Air leakage
Process changes
Compare compressor loading and pressure during normal and peak production.
9. Simultaneous Equipment Operation
Several high-demand machines starting together can cause a temporary pressure drop.
Record:
Time of pressure loss
Machines operating
Compressor load
Receiver pressure
Production cycle
Duration of the event
A pressure data logger can help identify short events that are difficult to observe manually.
10. Faulty Condensate Drain
A drain that remains open can continuously release compressed air.
Inspect:
Air receiver drains
Filter drains
Dryer drains
Moisture separators
Automatic drain valves
A drain problem may appear small but operate continuously.
11. Compressor Cannot Meet Demand
Possible causes include:
Insufficient compressor capacity
Reduced compressor output
Intake restriction
Worn internal components
Incorrect pressure settings
High operating temperature
Control-system problems
Excessive leakage
Do not conclude that a larger compressor is required until leakage and distribution restrictions have been investigated.
12. Air Receiver Problems
An air receiver helps stabilise pressure and support short demand peaks.
Possible issues include:
Insufficient receiver capacity
Water accumulation
Restricted connection
Faulty isolation valve
Pressure-sensor problems
Pressure-containing equipment must be inspected according to the applicable procedures.
How to Measure Pressure Drop
Step 1: Select Measurement Points
Possible locations include:
Compressor outlet
After the dryer
Main distribution line
Branch line
Before the machine
After the regulator
Step 2: Record No-Load Pressure
Measure when the connected equipment is not consuming significant air.
Step 3: Record Loaded Pressure
Measure during normal or peak production demand.
Step 4: Compare the Locations
Identify where the largest pressure difference occurs.
Step 5: Investigate That Section
Check filters, valves, pipe size, leakage and fittings.
Useful Compressed-Air Measurements
What to CheckRecommended InstrumentSystem pressureSuitable pressure gauge or digital manometerPressure at multiple locationsPortable pressure meterFilter pressure dropDifferential-pressure meterSmall air leakageUltrasonic leak detectorCompressor motor currentClamp meterCompressor temperatureThermal camera or infrared thermometerCompressor vibrationVibration meterPressure changes over timePressure data loggerRoom temperatureTemperature data logger
Using a Clamp Meter
A clamp meter can show how compressor motor current changes between:
Loaded operation
Unloaded operation
Peak demand
Normal production
Reduced production
Longer or more frequent loaded operation may indicate increased demand or leakage.
Using Thermal Imaging
A thermal camera can help inspect:
Compressor motor
Cooler
Electrical terminals
Discharge pipe
Dryer
Pipe connections
Hot restrictions where temperature differences are visible
Thermal imaging supports investigation but does not directly measure airflow or pressure loss.
Using a Data Logger
A pressure or operating-condition logger can help identify:
Short pressure drops
Shift-related problems
Peak production demand
Night-time leakage
Compressor cycling
Recovery time
The logging interval should be short enough to capture the event.
Basic Compressed-Air Pressure Investigation
Step 1: Record Compressor Pressure
Note loaded and unloaded operating pressure.
Step 2: Measure Pressure at Production Equipment
Check pressure while the machine is operating.
Step 3: Compare Intermediate Locations
Identify which pipe section or component creates the largest loss.
Step 4: Inspect Filters and Dryers
Check differential pressure and service condition.
Step 5: Search for Leakage
Inspect couplings, drains, valves, hoses and machinery.
Step 6: Review Air Demand
Identify equipment operating during the pressure-drop event.
Step 7: Check Compressor Load
Measure motor current and operating cycle.
Step 8: Review Pipe Design
Consider diameter, length, bends and branch arrangement.
Static vs Dynamic Pressure Check
Static Condition
The system is pressurised with little or no airflow.
A restriction may not be obvious.
Dynamic Condition
Production equipment is consuming compressed air.
Restrictions and undersized pipes produce a larger pressure drop.
Always investigate complaints under the operating condition in which they occur.
Common Troubleshooting Mistakes
Avoid:
Increasing compressor pressure immediately
Measuring only near the compressor
Checking pressure when production equipment is off
Ignoring small continuous leaks
Replacing the compressor before checking filters and pipework
Ignoring faulty drains
Measuring without recording production demand
Assuming pressure loss always means low compressor capacity
Failing to compare upstream and downstream pressure
Ignoring regulator condition
Using an unsuitable gas or pressure instrument
Approaching pressurised equipment without the correct procedure
Corrective Directions
Depending on the confirmed cause, actions may include:
Repairing air leaks
Replacing blocked filters
Servicing the dryer
Repairing drains
Opening or replacing valves
Correcting regulator problems
Increasing pipe diameter
Adding a ring-main arrangement
Reducing unnecessary air use
Separating high-demand equipment
Adding suitable receiver capacity
Restoring compressor performance
System changes should be designed and implemented by appropriately qualified personnel.
Compressed-Air Testing Tools Supplier in Malaysia
MTM Precision supplies instruments for investigating compressed-air pressure loss, leakage, compressor loading, overheating and vibration.
Our range includes pressure meters, differential-pressure meters, ultrasonic leak detectors, clamp meters, thermal imaging cameras, Smart Sensor AR600E infrared thermometers, vibration meters and data loggers.
Contact MTM Precision
MTM Precision Sdn. Bhd.
Showroom & Service Centre
No. 29-1 & 29-2, Jalan Bandar 18,
Pusat Bandar Puchong,
47160 Puchong, Selangor, Malaysia
🌐 Website: www.mtmpre.com.my
📧 Email: mtmpre@yahoo.com
📱 WhatsApp: +6016-660 7346
31 Aug 2026
