Thanks everyone for the responses. I think we'll end up doing the pressure test with water, or maybe purging the entire system. Our QC guys won't accept consumable inserts or flux coated tig wire so those options are out. As a new system, we are required to flush the system with flushing oil...
looking for a material that will dissolve in hydraulic oil, that we can make a purge dam from - closure weld on a A312 316L hydraulic piping system, that we want to pressure test with oil .
