How does the system suppress

For positive pressure systems, if they are pressure systems, they can be connected together for joint pressure testing. If it is not a pressure system, then separate pressure testing is required. For negative pressure systems, a link is provided: http://bbs.hcbbs.com/thread-326453-1-1.html. A test plan for the airtightness of the evaporation system in new urea production plants can be created; the content of that link can be used as a reference for conducting negative pressure tests.

I’ve never seen one with negative pressure; I’m learning about it :)

It is best to test the negative pressure system separately from the positive pressure system, as pipeline design is based on the pressure of the medium flowing within them. Negative pressure pipelines require a lower pressure level during pressure testing, while positive pressure pipelines have a different pressure requirement; only when the pressures of both are similar can they be tested together； During the airtightness test, the pressure must be maintained continuously for 24 hours to calculate the leakage rate; if this rate is greater than 1%, the test is considered failed, while if it is less than 1%, the test is successful. The formula used is η=100/ε (P2×T1/P1/T2), where ε represents the difference between the initial time and a certain other time ； P is the absolute pressure (the sum of gauge pressure and atmospheric pressure), and T is the absolute temperature ； T1 and P1 are the initial temperature and pressure ； T2 and P2 represent the temperature and pressure at a certain moment

Positive pressure systems and negative pressure systems are pressurized separately; there are standard requirements for pressure testing, and following those standards is sufficient

For questions of this kind, it’s fine to ask colleagues here to help gain some basic knowledge, but it’s impossible to find the correct answer. When conducting experiments, it is necessary to follow the experimental procedures and protocols strictly. :lol