In order to determine how much refrigerant can be added in a used recovery bottle, first the neck of the recovery bottle must be read. This will show the WC (water column capacity) and the TW (tare weight). The bottle can only be filled with refrigerant to 80% of the WC. Next, the digital scale must be turned on and zeroed. Weigh the recovery bottle for the total weight of the recovery bottle and refrigerant. To determine the total weight of the bottle with refrigerant inside, multiply .8 by the WC. Then add the TW. Follow the calculations below step by step to determine how much refrigerant can still be added in the recovery bottle. Example: Finding the Allowable Capacity Remaining Inside a Recovery Bottle The Recovery Bottle has a WC of 47.6 lb and a TW of 27.5 lb .8 x 47.6 lb WC = 38.1 lb Allowable Capacity 38.1 + 27.5 lb TW= 65.6 lb Max Weight Allowed for the Bottle with Refrigerant 47.6 lb Actual Weight 65.6 lb – 47.6 lb = 18 lb Allowable Capacity Remaining This video explains the Recovery Bottle Weight Calculations during Step 4- https://youtu.be/xOy3twD-pmg Check out our book “Refrigerant Charging and Service Procedures for Air Conditioning”. The full outline is available at https://www.acservicetech.com/the-book If you have already purchased our book, be sure to tell local HVACR Instructors about our book and what you think of it. We would love to get the book into the hands of the next generation of HVACR Technicians! Published: 4/5/2019 Author: Craig Migliaccio About the Author:Craig is the owner of AC Service Tech LLC and the Author of the book “Refrigerant Charging and Service Procedures for Air Conditioning”. Craig is a licensed Teacher of HVACR, Sheet Metal, and Building Maintenance in the State of New Jersey of the USA. He is also an HVACR Contracting Business owner of 15 years and holds an NJ HVACR Master License. Craig creates educational HVACR articles and videos which are posted at https://www.acservicetech.com & https://www.youtube.com/acservicetechchannel