Owner`s manual

Dive Rite

Ch. 2 Pg. 4

Loop Over-Pressure Valve

The O2ptima rebreather uses a special valve as a loop over-

pressure relief. This valve will normally be operated in the open

position (turned fully counter-clockwise). Divers with a large tidal

volume may be required to close the OPV slightly to maintain the

proper loop volume.

During the ascent, the gas in the loop will expand, increasing

buoyancy and increasing the breathing effort slightly. Even though

the maximum volume in the Optima’s loop is relatively small, it is

important to set the OPV properly so that buoyancy shifts will be

kept to a minimum without any diver action. Excess gas can be

vented by exhaling around the outside of the mouthpiece, through the nose, by positioning the

body with the left side down and the exhalation counter-lung slightly elevated, or exhaling more

deeply into the loop forcing the OPV to operate.

Exhaling around the outside of the mouthpiece is the preferred method of manually dumping the

loop as this dumps gas from the diver’s lungs and the counter-lungs simultaneously and is easily

controlled.

The OPV can also be used as a water dump by assuming a position head-up, allowing the water

to collect at the bottom of the exhalation counter-lung and flushing the loop with diluent.

Canister

The Canister has been designed to be lightweight, easy to

assemble and disassemble, and to be thermally efficient. The

Canister has five “main” components: the Head, Sensor plate,

Center section, Water trap, and End-cap.

The head houses all the wiring, a solenoid, the sensor harness

connection block (“banana” block), solenoid electrical

connection jack and an external DIVA port. The sensor plate has

been designed for easy access to the underlying components,

holds up to four sensors and is secured in place by one SS screw.