What Material are the Bypass Valve and Valve Head Made of? December 18, 2023 18:13 Updated They are made of a plastic called Celcon and both products are NSF stamped. Bypass Valve: Valve Head: Related articles How Much Resin Should be in the Tank? Cloudy or Foamy Water How to Activate the Clean Feature Can the softener be transported on its side? Will a higher hardness setting give me softer water?