PetroStreet

We have 50 years old heat exchangers which are still hydrotested at the same pressures like ever before.
Are there any guidelines to perform test at a lower pressures, and what should be those scenarios to apply this?

I would say this is just a misconception as not the first time I am hearing this.
I remember recalling from my colleagues in Inspection that there is no such allowance provided by any code /standard /best practices to reduce the hydrostatic testing pressures for exchangers saying that they have been old.
I would not say much on this with my limited or "referred" knowledge here.