Frequently Answered Questions - FAQ

Products - Poseidon Regulators

Because of the history behind the Cyklon second stage, there is a compatibility issue with modern standard second stage hose fittings and to address this issue Poseidon offers Cyklon specific OEM heavy rubber hoses. These low pressure regulator hoses have a standard 3/8-inch male at the end that screws into the first stage LP port, and at the other end you'll find a fitting compatible with the Poseidon Cyklon second stage regulator body. The hoses have a pressure rating of {500 psi | 35 bar} and are Nitrox Ready. As with the Xstream and Jetstream second stages, there are adapters available which allows use of standard regulator hoses.

Modern Cyklon first stages have standard LP ports that are 3/8-incn and standard HP ports that are 7/16-inch. However, on the very old "classic" Cyklon first stage, the thread size of all ports was 1/8-inch because there were no universal standards. If you have one of these rare old classic first stages, there are adaptors so you can attach standard sized fitting to your first stage.

LP adapter: 1/8-inch Male = 3/8-inch Female (Poseidon item number 2415)

HP adapter: 1/8-inch Male = 7/16-inch Female (Poseidon item number 2910)

Historically, Poseidon incorporated the OPV for their Jetstream and Xstream second stages in a unique fitting on the end of their non-standard low-pressure second stage hose. In 2008 Poseidon updated their Xstream first stage design (the Mk3 designation) and Xstream/Jetstream second stages to no longer require a Poseidon-specific low-pressure regulator hose.

There are adapters available which allow use of standard regulator hoses with Poseidon regulators manufactured prior to 2008. However, you MUST include an over-pressure relief valve, either by adding an OPV to an unused LP port on your older (Pre-2008) Xstream first stage - OR - use a hose adapter that incorporates an OPV - OR - use a current (manufactured 2008 and later) Xstream first stage that already incorporates an OPV.

You can mix Jetstream and Xstream second stages on the same Xstream first stage, as these stages all work with the same intermediate pressure. But you can NOT mix Jetstream or Xstream stages with Cyklon stages. The reason is that the Cyklon regulators work on a higher intermediate pressure than the Jetstream and Xstream regulators.

Also, Poseidon has recently introduced the Cyklon X regulator which consists of one or more Cyklon second stages together with a version of the Xstream first stage which is configured for the higher IP required by the Cyklon. The Cyklon X first stage is similar in appearance to the Xstream first stage but etched with "Cyklon X 0110-006" on the bottom. The Jetstream and Xstream second stages must not be connected to a Cyklon X first stage, nor should Cykon second stages be connected to an Xstream first stage.

The Jetstream and Xstream first stage IP should be {123 psi | 8.5 bar} when measured with a cylinder supply pressure of {3000 psi | 200 bar}.

The Cyklon first stage works at a significantly higher IP of {166 psi | 11.5 bar} when measured with a cylinder supply pressure of {300 psi | 20 bar}.

The current Xstream Deep/Duration/Black, Jetstream Mk3, and Cyklon X models manufactured after 1-Jan-2015 are all Nitrox Ready from the factory. Older Xstream Deep, Cyklon 5000 and Jetstream models were not Nitrox Ready from the factory and should only be used with gases containing a maximum of 23.5% oxygen.
A whistling noise can sometimes be heard when the Xstream first stage is pressurized or depressurized, and may be more noticeable on the surface or with lighter gases such as Trimix. This is due to a resonance frequency which takes place between the ball bearing and the actuating pin. This noise should not be detectable during low flow rates such as while breathing underwater. The noise has absolutely no effect on the regulator functionality. In most cases, the noise occurs on new or recently serviced units and will disappear with use.