These Edwards nXDS series dry scroll pump tip seal kits are used when a minor rebuild service is required. This is typically needed 2-years after the pump is placed into service, often required between 12,000 and 16,000 operating hours. The pump will start to lose its ability to reach the lowest ultimate pressure as the tip seals become worn out. The base pressure for a new nXDS pump is often measured at 10 mTorr or less when evacating a good clean leak-tight vacuum chamber. If you notice that your base presure is now only getting to 25 mTorr then the tip seal will likely need to be replaced. Please see the instructions shown in the tip seal replacement manual in our Downloads section below