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Oxygen First Stage - FS101A
Oxygen First Stage - FS101A Oxygen First Stage - FS101A Oxygen First Stage - FS101A

Oxygen First Stage - FS101A

FS101A
Incl. VAT: £176.82 £147.35  Excl. VAT

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FS101A - Oxygen First Stage

Replacement part for all AP rebreathers

The AP Diving FS101 (diluent), FS101A (oxygen), and FS101A/G (oxygen with Euro Thread) 1st stages are designed specifically for the AP Inspiration range of closed-circuit rebreathers.Read More

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As a responsible CCR manufacturer, it has always been our policy to only sell complete rebreathers or CCR spare parts to trained divers with an appropriate level, AP rebreather-specific, qualification from one of the recognised Rebreather Training Agencies. Please follow the button below for more details.

 

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FS101A - Oxygen First Stage

Replacement part for all AP rebreathers

The AP Diving FS101 (diluent), FS101A (oxygen), and FS101A/G (oxygen with Euro Thread) 1st stages are designed specifically for the AP Inspiration range of closed-circuit rebreathers. They are state-of-the-art 1st stages utilising a diaphragm-based balanced design, a unique port layout scheme and a 'stream-through' design to combat freezing. 

They are CE approved and designed to easily pass the EN250:2000 norm for performance and anti-freezing. 

These stages are manufactured specifically for the AP Inspiration range of closed-circuit rebreathers. This has resulted in the following special features:

  • 4 LP ports and 2 HP pressure ports that are placed in a non-standard position to accommodate perfect hose routing within the casing of the Inspiration rebreathers, both on the diluent-side (FS101) and oxygen-side (FS101A) of the rebreather.
  • An anti-freeze approach utilising large stream-through ports on the diaphragm side of the 1st stage, allowing the ambient water to transfer its above-zero warmth to the 1st stage. 
  • The choice of materials used in manufacture, support this heat transfer.
  • A very stable medium pressure delivery, even at depth. This is accomplished by using the above described heat transfer approach instead of the more popular “sealing” approach. Sealed 1st stages (where the diaphragm is kept isolated from the environment by an oil- or air-filled space and a second, flexible membrane) typically creep up in medium pressure at depth, as such bringing with them the danger of a solenoid not operating due to the medium pressure being too high. 

The design and gas delivery capacity of this 1st stage is such that it will easily accommodate open-circuit usage at depth as well. When used in a rebreather, this means this 1st stage can also fulfil an “open circuit bail-out” role when needed at any depth the Inspiration rebreathers are rated for.

PLEASE NOTE: The RB17 14 Bar Pressure Relief Valve is not included with a replacement First Stage and needs to be purchased separately. 

The RB17 is an over-pressure valve that screws into a spare low pressure port on your first stage. If the high pressure seat fails on your first stage, the RB17 will vent when the interstage pressure reaches 14 bar and so prevents high pressure gas delivery to your second stage.

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