Links
Valves
Polar Bear
www.acschradervalves.com/
A website dedicated to the sale and distribution of Schrader valves. Important information on how Schrader valves work and the associated issues in using them in auto acc applications.
Refrigerants
EPA
www.epa.gov/spdpublc/title6/609/technicians/retrguid.html
Guidance on Retrofitting to HFC-134a The term "retrofit" describes special procedures required to convert an R-12 system to use an alternative refrigerant. This document will describe some facts about aftermarket options and procedures for retrofitting a vehicle's air conditioning system to R-134a.
APS
www.epa.gov/Ozone/title6/608/608fact.html
Complying With The Section 608 Refrigerant Recycling This fact sheet provides an overview of the refrigerant recycling requirements of Section 608 of the Clean Air Act of 1990, as amended (CAA), including final regulations published on May 14, 1993 (58 FR 28660), August 19, 1994 (59 FR 42950), November 9, 1994 (59 FR 55912), and July 24, 2003 (68 FR 43786). The fact sheet also describes the prohibition on intentional refrigerant venting that became effective on July 1, 1992