Butyrate vs Acrylic in outdoor weathering valve stems
Decades ago, Rodney Hunt Company, Orange MA and Waterman Industries, Inc., Exeter, CA began using our butyrate tubing to protect their stems from weathering. Butyrate (CAB) protectors provided clarity, UV protection, and fracture resistance without the weight and other drawbacks of steel pipe.

To the right: Acrylic tubing from months-old to several years old. Notice the yellowing, to browning. The tube (second to the left) was only in use for less than one year. With the color change comes easy breaking.
Butyrate tubing, even after some long-term stress cracking will remain structurally sound for years.

Typical valve-stem application
For butyrate properties:Eastman Chemical formula 576E