Ammonia penetration and helium testing of shell-and-tube heat exchangers
Thread Content
I would like to ask fellow shipbuilding industry professionals: do newly manufactured heat exchangers require ammonia permeation testing and helium testing? Our company has purchased a shell-and-tube reboiler with a surface area of 60.8㎡, and the heat exchanger manufacturer only offers pressure testing and airtightness testing – is it possible to ask this manufacturer to carry out ammonia permeation testing and helium testing as well?
In leak testing, a gas-tightness test is inexpensive, safe, and practical, and manufacturers generally prefer it as well. If the user wants ammonia, halogen, or helium leak detection, should it be specified in the technical specifications of the contract or during the design drawing approval phase?
Why is ammonia leakage detection and helium leak testing necessary? Are there such high requirements for sealing? From an economic perspective, a slight amount of leakage is generally allowed, and even airtightness is not required. Ammonia or helium leak testing is considered only for the first group of media where minimal leakage is not permitted, or where high vacuum or ultra-high vacuum levels must be maintained. The reason is that the degree of sealing varies, as do the manufacturing methods and costs, resulting in significant differences.
It can be specified in the preliminary technical agreement