Is device airtightness checked before or after the three inspections and four adjustments?

Airtightness testing is carried out after the three inspections and four adjustments

There’s no need for any rules like “three checks and four determinations” here; it’s clearly a quality issue on the part of the contractor, and it’s the contractor who must address it. The most basic engineering acceptance requires meeting the standards. Otherwise, corresponding application and management control mechanisms must be implemented. I’m not sure if you have the authority to do this; if not, it’s best to report it to your superiors. This cannot be handled carelessly in a project context.

The three inspections and four determinations are carried out before the handover at intermediate stages, during the equipment construction phase, when it has not yet been handed over to the operations department or workshop for management; therefore, airtightness is not checked at this time. During the commissioning phase of the installation, the construction party has personnel on site to ensure proper operation; leak sealing is usually carried out in the workshop, but it is of course the construction party that handles any detected leaks.

The issues related to construction should be the responsibility of the construction party.

Work is carried out in a cross-wise manner, with the principles of three inspections and four determinations applied throughout the entire construction period. Using intermediate handovers as milestones, airtightness testing is generally conducted in stages; units that have completed pressure testing can then undergo airtightness checks. Thus, by working in this cross-wise fashion, any issues identified during the airtightness testing process can also be addressed through the three inspections and four determinations.

The three checks and four confirmations are essential processes in intermediate handovers; once the handover is completed, the final checklist serves as a basis for completion and as a reference for inspection and approval. At this point, airtightness testing may already be carried out in some systems that meet the requirements, but it has not yet been done in most systems; therefore, there is no clear boundary, nor are there any rules specifying whether it must be done before or after the three inspections and four adjustments. As for eliminating leaks, most of the tasks fall on the construction company, as it is their responsibility related to the construction work. However, in some cases where the deadline is tight, the owner will send his own maintenance workers to help with the repairs, but in terms of responsibility, it should still lie with the construction company.

It is better to leave it to professional installation teams; any sealing test should be thoroughly checked before the system is put into use, to ensure it meets the required standards.

Airtightness testing should be carried out after the three inspections and four adjustments