Circle Seal Controls, Inc. is the manufacturer of the one way valve, Kirby Morgan P/N 555-195
Circle Seal Controls, Inc. has made a change to their one-way valve that they manufacture; they have replaced the stainless steel spring guide with a brass spring guide.
The brass spring guide functions in the same manner as the stainless steel spring guide.
Flow testing was performed by Kirby Morgan and more extensively at Dive Lab. The flow rates were unchanged.
After testing it was determined the changes would not affect fit form or function.
Valves with the brass spring guide, as well as the valves with a stainless steel spring guide are both acceptable for use by Kirby Morgan.