What does a qualified bubble look like during the leak test?

It is necessary to check whether the gasket has any defects; if there are defects, leaving it in use despite a pass verdict will pose hidden risks, so it is recommended to relieve pressure and replace the gasket. If it is no longer possible to make a replacement, it is recommended to use a fixture and not apply glue for now; in the event of a leak, glue can be applied as a temporary solution.

Replace it with a new one; if the level of airtightness is already at the highest possible level and replacement is not feasible, pressure-sealing can be used as a solution. It is necessary to contact the relevant party in advance and provide the necessary conditions for manufacturing the mold and injecting glue.

Is everyone’s opinion to overhaul the heat exchanger? Will the expansion of graphite after heating reduce the leakage?

During pressure testing, it is not allowed to repair leaks while the system is under pressure; the pressure must be released first for repairs to be made, after which the pressure test can be conducted again. Personally, I think it’s necessary to check the sequence in which the bolts are tightened; often, minor leaks are not related to the equipment itself, but rather to the method of installation

It also depends on the rate of leakage. What we call this is \"crab soaking\" – if a large amount of leakage occurs in a short period of time, it’s necessary to check the sealing surfaces and gasket defects, and replace them promptly

The bolts are not tightened to the extreme; even force must be applied from all four sides, so the graphite gaskets need to be replaced. In such cases, no matter how tight it is, it’s useless; you need to take it apart and reinstall it

Since the gasket is damaged, even using a hydraulic wrench to pull it will have little effect, and it may also damage the sealing surface. In such cases, multiple inspections have usually been carried out, and checking the tightening sequence is pointless; exceeding the bolt’s tensile strength can also lead to other hazards. Most issues are not related to the equipment itself, but rather to the flange surfaces. When the equipment is delivered to the site, the contractors may not take care of protecting those flange surfaces, and rust and damage can occur, which will certainly affect the sealing performance of the high-pressure flanges. To deal with such problems, relieve pressure where possible; if conditions for pressure relief do not exist and leakage is likely to occur, consider the pressure level and contact a company specialized in plugging leaks under pressure to conduct a risk assessment and determine the appropriate course of action. Generally, the latter occurs rarely; as construction management improves, damage to the sealing surfaces happens less and less often~~~~

1. Is the flatness of the flange and the quality of the sealing surface checked during installation? 2. Is the quality of the gaskets also checked? 3. Was flange alignment (including parallelism) ensured during installation? 4. Was a hydraulic wrench used for tightening? What is the torque required for tightening, and according to what standards is it calculated? What are the design operating conditions, and what are the actual operating conditions? 5. What is the sequence for tightening? 6. Has anti-seize agent been evenly applied to the bolts? Wait ======================= Leaks at the flanges when there is a gas seal are very common. It’s a technical task. It usually passes the airtightness test, but leaks right after starting up with material feeding. Compared to leaks that occur during operation, leaks when the system is airtight still represent the detection of problems at an early stage.

In short, leaks can occur during design, installation, as well as storage and transportation. The treatment of key flanges must be carried out in strict accordance with standards; otherwise, if leakage occurs once the equipment is started up, the cost of stopping operation to fix the issue will be high. If you have any questions, contact me within the site.

Damaged flange sealing surface? During the construction phase, don’t you, as the project owner, participate in the unpacking inspection before the contractor installs the equipment? Are no inspections carried out for inspection lot acceptance, sub-projects, divisional projects, or complete projects? Since the sealing test has been completed, it should be time to move on to the acceptance phase for the individual project, right?