Aqua Lung Black Diamond SL BC - Manual (Page 19)

18 Black Diamond Owner’s Manual Black Diamond Owner’s Manual 19
Overpressure Relief (OPR)/Dump Valves
In addition to the overpressure relief (OPR) valve that is integrated into
the dual valve, the Black Diamond has three other OPR/dump valves:
Two are located at the bottom of the air bladder on the left and right
hand sides (Fig. 17a); the third is located on the right shoulder (Fig. 18a).
Their primary function is to relieve excess air pressure inside the blad-
der, but they can also be opened manually by pulling on the ball and
cord assembly to quickly dump air (Fig. 17b & 18b).
a
To dump air as quickly as possible, always use the dump valve at the
highest point in the water column. For example, the lower rear valve
works best while making a head-first descent, or swimming in a face-
down position; the dual valve works best when in an upright position.
CAUTION: The proper function of either overpressure relief
valve is vital to prevent damage to the BC bladder. Unau-
thorized service or tampering may render these valves in-
operable, and could cause the bladder to leak or burst. This
type of damage is not repairable, and is not covered under
warranty.
WARNING: Most training agencies recommend that you
should descend in an upright, feet-first position, in order
to maintain a slower and more controlled descent. This is
especially true if you experience difficulty equalizing your
ears, or if you are descending in low visibility conditions.
Fig.17
a
b
b
a
Fig. 18 b