Si Tech or Apeks valves

[oxyhacker]

The Apeks valve has a slightly larger threaded base where it goes through the suit, however you can usually use a Si Tech valve in the larger hole.

However, to really do it right, Si Tech makes a special #60810 installation ring (which they call a "port") which is cemented to the suit, and has a little collar to fill the extra space. This makes for a much more reliable and rugged installation

Si Tech valves are available from Bob3, who is a regular on this list, from Divetech in Hampton VA, and Dyk Brand in Sweden.

How difficult is it to replace an Apex valve with a SI-tech one? Are they the same size? fit the same size hole? maybe even fit a common base?

Where can I get a Si-tech valve? I am considering a dry suit, and the maker only has Apex valves available, but will install a Si-tech instead, if I provide it...