Revision of the Professional Technical Manual (CTP) on the in-service monitoring of pressurized refrigeration systems

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‍General information on the in-service monitoring of pressure equipment and simple pressure vessels

Pressure equipment and simple pressure vessels are vessels, piping, safety accessories, and pressure accessories with a maximum allowable pressure (PS) greater than 0.5 bar.

The in-service monitoring of this pressure equipment, when subject to such requirements, must be carried out in accordance with the decree of November 20, 2017:

• either based on the periodic inspections and requalifications prescribed by this decree;
• or following an inspection plan prepared by a qualified person under the operator's responsibility and approved by an authorized body, a Recognized Inspection Service (RIS), or by the operator for piping not subject to requalification (i.e., piping not subject to declaration and commissioning inspection).

Inspection plans must be established in accordance with professional guides or professional technical manuals (CTP) approved by ministerial decision, as listed in Annex 2 of the Order of November 20, 2017.

Among these documents, the CTP for the in-service monitoring of pressurized refrigeration systems allows for the monitoring of vessels or vessel compartments, piping, and their constituent pressurized accessories within a refrigeration system containing refrigerant, as well as the safety accessories that protect them.

This CTP was recently updated. The version dated April 8, 2026, must now be used (with the exception of paragraphs E.1.2.3 to E.1.2.5, which were not approved) starting from^August 1, 2026.

Why monitor these pressurized refrigeration systems using a CTP?

Given their specific characteristics, pressurized refrigeration systems require a CTP. These systems:

• must generally remain operational to ensure continuous cold production, which is essential for preserving food products and protecting data centers, security systems, and safety systems, among others; 
• do not tolerate the introduction of moisture into the circuits. The refrigerant/material combinations specified in the CTP do not cause internal corrosion; 
• are designed to prevent:
  
  • refrigerant leaks;
  • moisture migration under the insulation. 

The difficulties mentioned above make it impossible to meet the in-service monitoring requirements defined in the Order of November 20, 2017, regarding:

• hydrostatic testing;
• internal inspection;
• external inspection of the metal walls of insulated equipment. 

In practical terms, in-service monitoring according to this CTP specifically allows for: 

• an exemption from hydrostatic testing during periodic requalification;
• an exemption from systematic stripping of equipment during periodic inspections and requalifications;
• the ability to deviate from the regulatory frequencies for periodic requalifications defined in the decree of November 20, 2017: every 12 years for non-hazardous fluids (compared to 10 years in the decree) and every 6 years for hazardous fluids (compared to 5 years in the decree).

What are the new features introduced in the CTP for pressurized refrigeration systems?

Among the notable new features introduced in this CTP, the following modifications should be mentioned: 

• To the operating records (part A.1 of the CTP):
  
  • a new distinction between documents to be kept based on three cases (CE equipment integrated into a CE assembly, standalone CE equipment, and equipment subject to former French regulations);
  • addition and removal of certain documents related to operation (for example, the plan approval decision and safety valve recalibration certificates have been added);
    

• To the inspection plans (part A.2 of the CTP). These inspection plans must now include:  
  
  • any Critical Operating Limit Conditions (COLC) regarding degradation modes, and their thresholds;
  • the areas to be inspected based on the identified degradation modes. This list is supplemented, where applicable, by checks related to degradation modes not covered by this CTP but specific to the refrigeration system in question.
    

• To the Initial Verifications (part A.3):
  
  • the inspector must now ensure that the operator has formalized the recognition of the competence of the operating personnel;
  • the presence, compliance, and legibility of markings (nameplates on the equipment or the CE assembly) are now checked.
    

• For Periodic Inspections (part A.4):
  
  • new external visual checks are now required to detect any defects in equipment or assembly markings, where applicable;
  • non-conformities (whether or not they affect the safety level) must undergo a new inspection to be cleared.
    

• For Periodic Requalifications (part A.5):
  
  • to grant requalification, all inspections scheduled in the inspection plan must be completed within the interval between commissioning and the first requalification, or between two requalifications;
  • as part of the safety accessory verification, the functionality of the high-pressure safety switch circuit must now be tested.
    

• For feedback (part A.10). The online questionnaire (linked in Annex III of the CTP) must be completed by operators of pressurized refrigeration systems before March 15 of year n for the period of year n-1 (instead of once every two years).
  

What is the impact on existing inspection plans?

Operators must revise their inspection plans before the next inspection or monitoring operation scheduled in the plan in effect as of August 1, 2026. Revisions to these inspection plans must be approved no later than the first periodic requalification following August 1, 2026.

Please note, however, that the frequencies and content of periodic inspections and periodic requalifications defined in this new version of the CTP apply starting from the first periodic inspection or periodic requalification on or after April 17, 2026.