The IP Blanking Plug and Stronger Spring in the DGX Static IP Kit are used to change the behavior of the intermediate pressure in first stage regulators to allow them to be used with CMF orifices and needle valves found on some types of rebreathers. The Apeks DS4 a popular first stage used on rebreather designs that rely upon constant mass flow (CMF) for their function. The Apeks first stage is not included, but available as an optional add-on and when included the selected items will also be installed by our service technician trained to service Apeks products.

IP Blanking Plug (aka APR plate or blinding cap) - Compatible with the Apeks DS4 and DST plus the Well Marine Diving FS819, this machined polyoxymethylene (aka POM, Delrin, acetal) blanking plug and oxygen compatible O-ring will seal the ambient pressure chamber; disabling the automatic depth compensation for the intermediate pressure thus creating an absolute pressure regulator. Its intended application is with rebreather designs which require a fixed intermediate pressure that is not depth compensated and does not change. Other than to replace the original flexible diaphragm with this rigid blanking plug, no additional modification to the regulator is needed. Caution: Attempting to open-circuit dive using a first stage that does not compensate for depth will result in declining performance as the diver descends; eventually the regulator will no longer deliver adequate breathing gas once the ambient pressure at depth equals the IP of the first stage.

Stronger Spring - This stainless steel spring has similar dimensions to the original Apeks factory supplied RG912271 spring in the DS4 and DST first stages, but is much stronger. The intended application is with rebreather designs which require substantially higher than normal IP settings to extend their depth range. The extra strength of the spring increases the IP adjustment range to between 12 bar to 20 bar, and it also becomes impossible to adjust the IP below {175 psi |12 bar}. Assuming a blanking plug is installed then, other than replace the original spring with this Stronger Spring, no additional modification to the regulator is needed. However, the new IP range is well above the Apeks recommended 9 to 10 bar setting for normal Apeks first stages. The higher IP will make most OPVs release unless they are adjusted, also some low-pressure hoses are only rated { 250 psi | 27 bar} maximum service pressure. The Stronger Spring is used in conjunction with the blanking plug, but you only need the spring if you are planning on diving your rebreather below about { 330 fsw | 100 msw } based on a DS4 intermediate pressure set to the 12 bar minimum and the rEvo rebreather.

Advisory: Installation of these devices will substantially change the functional behavior of the first stage regulator and their misuse can result in serious injury or death.