In past two weeks, ITW/ ITE primary vacuum back up lines and BVs in ITW/ITE pit have been leak checked.  ITW BV1 and BV2 on back up line side were leak. They are replaced with old leak free BVs.  ITE TP2 NW25 SST  flexible line right after pump were leak . It is replaced with new NW25 SST flexible line. Two leak were found on ITW side KF 50 O-rings connected to NW 50 SST flexible coupling. They were replaced with new KF50 o-rings. After job, both  stations primary back up lines in pit were leak checked .  They are good.