We get so much slack when we push Hydrostatic Pressure/Leak Testing vs. Pneumatic testing. So many think that pneumatic is easier and cheaper, when in reality it is NOT. In fact, the B31 series makes it clear that HYDROSTATIC is the first choice for pressure and leak testing. The code makes it clear that pneumatic is for when the piping pressure and leak test can NOT be done by the hydrostatic method due to the weight of the test fluid (i.e., water), the quality concerns with the test medium not being fully removed from the piping, and/or the safety and health concerns if the test medium is not being fully removed from the piping (water reactivity). It is this last exception that got used recently on a Hot Oil system. The contractor claimed that, if any water was in the system when the oil began to heat up to 485°F, the piping would be at risk of damage due to water expansion. I bought off on that concern and allowed them to use the pneumatic method. But here’s the catch… they used a standard air compressor that delivers compressed air with a dew point between 35°F to 50°F. Here is the issue…