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: Diving regulators use mechanically operated valves. In most cases there is ambient pressure feedback to both first and second stage, except where this is avoided to allow constant mass flow through an orifice in a rebreather, which requires a constant absolute upstream pressure. Back-pressure regulators are used in gas reclaim systems to conserve expensive helium based breathing gases in surface-supplied diving, and to control the safe exhaust of exhaled gas from built-in breathing systems in hyperbaric chambers . The parts of a regulator are described here as the major functional groups in downstream order as following the gas flow from the cylinder to its final use. Details may vary considerably between manufacturers and models. Contents
1 Types of diving regulators
2 Open-circuit scuba regulators
2.1 Connection to the high pressure supply
2.1.1 CGA 850 connection
2.1.2 DIN connection
2.1.3 Adapters
2.1.4 Conversion kits
2.1.5 Other connection types
2.1.6 Cylinder valve types
2.2 Single-hose demand regulators
2.2.1 First stage
2.2.1.1 Piston-type first stage
2.2.1.2 Diaphragm-type first stage
2.2.1.3 Balancing
2.2.2 Interstage hose
2.2.3 Second-stage
2.2.3.1 Upstream valves
2.2.3.2 Downstream valves
2.2.3.3 Servo-controlled valves
2.2.3.4 Exhaust valves
2.2.3.5 Exhaust manifold
2.2.3.6 Purge button
2.2.3.7 User adjustable flow modifiers
2.3 Twin-hose demand regulators
3 Constant mass flow regulators
4 Surface supply regulators
5 Reclaim regulators
6 Built-in breathing system regulators
7 Malfunctions and failure modes
7.1 Inlet filter blockage
7.2 Sticking valves
7.3 Free-flow
7.4 Intermediate pressure creep
7.5 Regulator freezing
7.5.1 Mechanism of icing
7.5.2 First stage freezing
7.5.3 Interstage gas temperature
7.5.4 Second stage freeze
7.5.5 Surface supplied breathing equipment
7.5.6 Factors increasing the risk of regulator freeze
7.5.7 Precautions to reduce risk of regulator freezing
7.5.8 Mitigation
7.5.9 Procedures for managing a regulator freeze
7.6 Gas leaks
7.7 Wet breathing
7.8 Excessive work of breathing
7.9 Juddering, shuddering and moaning
7.10 Physical damage to the housing or components
8 See also
9 References
Types of diving regulators
Gas pressure regulators are used for several applications in the supply and handling of breathing gases for diving. Pressure reducing regulators are used to reduce gas pressure for supply to the diver in demand and free-flow open circuit breathing apparatus, in rebreather equipment, and in gas blending procedures. Back-pressure regulators are used in the exhaust systems of the built-in breathing systems of diving chambers, and in the recovery of used helium based breathing gas for recycling. Some of these regulators must work underwater, others in the more forgiving conditions of the surface support area. All must work consistently and reliably, but some are parts of safety-critical life-support systems, where a single point of failure must not put lives at risk.