Glossary > #PTI

PTI – Pre-Trip Inspection

Pre-Trip Inspection (PTI) is a comprehensive technical and visual control process performed on an empty refrigerated (reefer) container before it is handed over for cargo loading. The key purpose of PTI is to ensure that the refrigeration unit, control systems, sensors, recording devices, and the container structure itself are in perfect condition and ready for transporting sensitive goods. Inspection is essential especially for the transport of food, pharmaceuticals, chemicals, and other commodities requiring controlled temperature.

The PTI process includes:

Visual inspection (structural integrity, seals, cleanliness, absence of corrosion or mechanical damage)
Functional tests of the refrigeration unit (compressor, fans, sensors, electronics, recording devices)
Automated test sequences (diagnostics, simulation of operating modes, verification of alarms and safety elements)
Recording and documentation of results (digital, physical sticker, system records)

The output of PTI is always a clear assessment: PASS or FAIL. If PTI does not pass, the container is not released for transport and must be repaired and tested again.

Key Related Terms

Term	Meaning
Reefer container	Specialized container with an active refrigeration unit.
Refrigeration unit	System including compressor, condenser, evaporator, fans, and electronics.
Setpoint	Desired transport temperature set on the unit.
Datalogger	Integrated device for recording temperature, humidity, and operating states.
Pre-Cool	Process of pre-cooling the cargo itself before loading into the container.

Importance and Key Benefits of Pre-Trip Inspection

Why is PTI absolutely necessary?

Cargo protection: Ensures that the refrigeration unit will not fail during transport, thereby protecting sensitive goods from deterioration. For pharmaceuticals or food, losses due to cooling failure are extremely high.
Prevention of claims and legal disputes: PTI serves as proof that the carrier provided functional equipment. Without valid PTI, the risk of claims and insurance events is significantly higher.
Operational efficiency and reliability: Early detection and repair of defects at the depot is always cheaper and faster than resolving a failure during transit or at sea.
Compliance with international standards and insurance: Many shipping contracts, standards (e.g., ISO 1496-2), and insurance conditions require valid PTI before each loading.
Transport safety: Regular inspection of electrical and mechanical parts minimizes the risk of fire, short circuit, or refrigerant leakage.

Comprehensive Pre-Trip Inspection (PTI) Process

Phase 1: Visual and Manual Inspection (Power Off Mode)

Before any connection of the unit to power, a thorough visual and manual inspection is performed:

Inspection Checklist – Visual Inspection:

Interior cleanliness: No residue from previous cargo, mold, odors, pallet remnants, or packaging.
Wall and floor damage: No holes, cracks, panel delamination, damaged T-profiles.
Door seals: Must be soft, elastic, undamaged, without cracks (cold air leakage significantly reduces efficiency).
Drainage channel inspection: Must be clear, without blockages (preventing water and ice accumulation).
Condition of external shell and frame: No corrosion, dents, deformation, loose hinges, or locks.
Condition of power cable and plug: Undamaged, without cracks, clean, functional protective cover.
Condition of ventilation openings and filters: Unobstructed, functional.
Presence of PTI sticker and its validity: Date of last PTI, readability.

Phase 2: Functional Tests (Power On Mode)

After successful visual inspection, the container is connected to the electrical network (usually 380/460V, 3-phase) and the following is performed:

Automated Tests and Diagnostics

Starting the refrigeration unit and software initialization: Firmware check, time setting, container identification.
Display and control panel verification: Correct values displayed, absence of error messages.
Sensor functionality verification: Temperature, pressure, humidity sensors – measurement and calibration, comparison with actual temperature.
Fan test (evaporator, condenser): Starting in various modes, current consumption measurement, absence of vibrations or noise.
Compressor test: Starting, current consumption, pressure increase in the circuit, response to setpoint changes.
Heater test (defrost heater): Activation and power measurement, defrost cycle simulation.
Defrost cycle test: Automatic simulation, water drainage control, valve and heater activation.
Alarm and safety element test: Pressure switch activation, response test to critical states.

Duration and Course of Tests

Complete PTI typically takes 3–4 hours, depending on the unit type and scope of tests.
For some manufacturers (e.g., Carrier, Thermo King), accelerated or shortened sequences can be run (so-called Smart PTI).

Phase 3: Evaluation and Documentation of Results

PTI Output

PASS: All tests were successful, the unit shows no errors or alarms. The container is labeled with a PTI sticker with the date, result, and technician’s signature. The result is recorded in the datalogger and in the central system (e.g., EDI communication with the carrier).
FAIL: A defect has been detected, the unit is blocked for loading. The technician records the error, performs the repair, and starts a new PTI cycle.

PTI Validity

Typical PTI validity is 30 to 180 days according to the carrier’s internal rules. Some companies may shorten validity in case of long-term storage or extreme weather conditions.
After validity expires, a new PTI must always be performed, otherwise the container cannot be used for transport.

Responsibility and Records

Responsibility for PTI performance always rests with the container owner/operator (usually the shipping company).
Documentation: Physical sticker on the container, digital record in the unit, records in the carrier’s internal system (often linked to global databases, possibility of remote monitoring).

Types of PTI Tests and Approaches

Type of PTI	Characteristics	Typical Use
Short PTI	Quick test of key functions, focused on fans, sensors, basic cooling	Chilled goods, quick turnaround
Full PTI	Long complex test including extreme temperature simulation, maximum load, diagnostics	Frozen goods, older containers
Smart PTI	Shortened test based on history without alarms, only visual and basic functional inspection	New units, trouble-free history

Most Common Defects Found During PTI

Defect	Possible Consequences and Risks	Solution
Damaged door seals	Cold air leakage, increased consumption, cargo damage	Seal replacement
Leaking drainage channels	Water/ice accumulation, increased humidity, cargo packaging damage	Cleaning, repair
Temperature sensor failure	Incorrect regulation, inability to maintain temperature	Sensor replacement, recalibration
Fan failure	Uneven cooling, overheating/freezing of some areas	Motor/fan repair or replacement
Refrigerant leakage	Reduced performance, environmental hazard	Leak detection, refrigerant replenishment, repair
Electronics errors (control unit)	False alarms, function failure, inability to set correct mode	Diagnostics, firmware update or electronics replacement
Dirty condensers/evaporators	Overheating, reduced performance, higher consumption	Cleaning, inspection

FAQ – Frequently Asked Questions

1. Is it possible to release a container with expired PTI?

No. No reputable shipping company will release a container without valid PTI. If validity has expired, a new PTI must be performed.

2. Is Pre-Cool a substitute for PTI?

No. Pre-Cool concerns only the temperature of the cargo, not the technical condition of the container.

3. What if PTI does not pass?

The container is taken out of service, the defect is repaired, and PTI is repeated. Everything is recorded in the documentation.

4. Who is responsible for PTI?

The container owner/operator, typically the shipping company.

5. How is PTI evaluated?

Unambiguously: PASS/FAIL. The result is recorded both physically and digitally.

Modern Trends in PTI and Remote Monitoring

Remote monitoring: Modern reefer containers allow online monitoring of operational data, alarms, and PTI history via GSM, satellite, or RFID systems.
Automation of records: PTI results are automatically entered into carriers’ central systems, enabling quick status checks of the entire fleet and maintenance planning.
Standardization of procedures: International carriers standardize checklists and test sequences according to ISO and manufacturer recommendations.

Conclusion

Pre-Trip Inspection (PTI) is a key process in the temperature-controlled logistics chain. Its careful performance and documentation is essential for cargo protection, minimization of claims, and ensuring safety and smooth transport. Modern technology additionally enables detailed monitoring and rapid assessment of the condition of each unit in real time, advancing the quality and reliability of transport to a new level.