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Regulators
SECTION II
DESCRIPTION AND OPERATION
2.0 GENERAL
TUSA Regulators are BALANCED PISTON and BALANCED DIAPHRAGM type
SINGLE HOSE REGULATORS. The regulator reduces high pressure air from the
scuba cylinder to ambient pressure suitable for breathing, through the operation of
first and second stage regulators. The first stage regulator reduces incoming high
pressure air, to an intermediate pressure of approximately 135PSI ( 9.5bar). The
second stage regulator, using a diaphragm operated demand valve, further reduces
air from intermediate pressure to ambient pressure permitting normal breathing. The
first and second stages of the regulator are connected by a low pressure hose. A
swivel yoke (TYPE INT) on the first stage body secures the regulator to the cylinder
valve, while an O-ring surrounding the outlet orifice on the cylinder valve ensures an
airtight connection to the first stage.
2.1 FIRST STAGE
R-700 first stage
The R-700 is a balanced diaphragm first stage with key design and performance
characteristics:
1) Four intermediate pressure ports and two high pressure ports, 2) Balanced first
stage, with a built-in antifreeze system, 3) Replaceable HP seat and HP poppet
for durability and servicing, 4) Two special high flow LP ports (HFP) close to the
diaphragm offer approximately 15% greater air flow, 5) Dry balance chamber
prevents water contact with the diaphragm and the spring for superior cold water
performance. The R-700 meets the European Standards EN250:2014 requirements
for cold water conditions.
R-800S first stage
The R-800S is a balanced piston type first stage offering superior reliability for
stable air supply regardless of depth or residual pressure. It is equipped with four
intermediate low pressure ports and two high pressure ports.
R1000 first stage
The R1000 is a balanced diaphragm first stage with four intermediate pressure ports
and two high pressure ports. Two special high flow low pressure ports (HFP) close
to the diaphragm offer approximately 15% greater airflow. The R1000 meets the
