I am writing a design-build specification for construction of several adjoining Class 100 cleanrooms and am using this specification (15481) as the starting point.

There will be a network of ultrahigh purity nitrogen piping with mains throughout the area and branches to the different clean rooms.

In the specification, it is mentioned that tubes requiring field cuts need to be filled with 25% IPA and 75% 18 megaohm deionized water, drained, and blown dry with nitrogen.

The contractor who will be doing this work says this is not possible because it would require filling the entire piping system with the liquid mixture and there would not be any way to guarantee all the liquid has been eliminated.

I am thinking of eliminating this portion of the specification, but am unsure if the contractor is accurate in his assessment.

If anybody could assist me – it would be appreciated.