Title: Mechanism of diving regulators - Wikipedia
Headings: Mechanism of diving regulators
Mechanism of diving regulators
Contents
Types of diving regulators
Open-circuit scuba regulators
Connection to the high pressure supply
CGA 850 connection
DIN connection
Adapters
Conversion kits
Other connection types
Cylinder valve types
Single-hose demand regulators
First stage
Piston-type first stage
Diaphragm-type first stage
Balancing
Interstage hose
Second-stage
Upstream valves
Downstream valves
Servo-controlled valves
Exhaust valves
Exhaust manifold
Purge button
User adjustable flow modifiers
Twin-hose demand regulators
Constant mass flow regulators
Surface supply regulators
Reclaim regulators
Built-in breathing system regulators
Malfunctions and failure modes
Inlet filter blockage
Sticking valves
Free-flow
Intermediate pressure creep
Regulator freezing
Mechanism of icing
First stage freezing
Interstage gas temperature
Second stage freeze
Surface supplied breathing equipment
Factors increasing the risk of regulator freeze
Precautions to reduce risk of regulator freezing
Mitigation
Procedures for managing a regulator freeze
Gas leaks
Wet breathing
Excessive work of breathing
Juddering, shuddering and moaning
Physical damage to the housing or components
See also
References

Content: The diver must take care not to screw the yoke down too tightly, or it may prove impossible to remove without tools. Conversely, failing to tighten sufficiently can lead to O-ring extrusion under pressure and a major loss of breathing gas. This can be a serious problem if it happens when the diver is at depth. Yoke fittings are rated up to a maximum of 240 bar working pressure. The outlet of the CGA 850 valve is on a flat surface on the valve body, inside a concentric face-sealing O-ring groove, with a conical indentation on the opposite surface of the valve body, co-axial with the O-ring groove. The yoke clamp fits around the valve body and the sealing face of the regulator inlet seats over the O-ring groove. A conically tipped screw locates in the indentation and when tightened, presses against the valve body and pulls the sealing face of the regulator inlet against the O-ring. This screw must be tightened sufficiently to maintain metal-to-metal contact between the regulator inlet and the valve body when the valve is opened at full cylinder pressure, and under normal working loads including minor impacts and using the regulator as a handle to lift the set, to prevent failure of the seal by O-ring extrusion and consequent loss of breathing gas. The screw must also not be over-tightened, as after use it must be removed by hand. The rigidity of the yoke varies depending on design, tightening is by hand and is left to the discretion of the user.