Uniweld 40055 Nitrogen Sludge Sucker Maintenance Kit with 0-400 PSI Maximum Delivery Pressure The Nitrogen Sludge Sucker and Blaster Maintenance Kit was specifically designed for multiple uses in the HVAC/R and Maintenance Industry Nitrogen Regulator with protective rubber gauge boots - Maximum Delivery Pressure up to 400 PSI Purging copper lines with low pressure nitrogen displaces the oxygen, preventing oxidation and the resulting scale Pressure testing a system for leaks prior to evacuating and charging will save time and money Cleaning a condensate drain line is easy with a Sludge Sucker or Sludge Blaster