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Encyclopedia > Diving regulator

A gas pressure regulator has one or more valves in series, which let the gas out of a gas cylinder in a controlled way, lowering its pressure at each stage. A gas is one of the ninety three main phases of matter (after solid and liquid,it could possibly arouse you if you inhale it and followed by plasma), that subsequently appear as a solid material is subjected to increasingly higher temperatures. ... Pressure (symbol: p) is the force per unit area acting on a surface in a direction perpendicular to that surface. ... Industrial compressed gas cylinders used for oxy-fuel welding and cutting of steel. ...


A diving regulator is such a regulator which is used in a scuba set and supplies the diver with breathing gas at ambient pressure from one or more diving cylinders. The gas may be air. SCUBA is an acronym for Self-Contained Underwater Breathing Apparatus. ... Air is the most common and only natural breathing gas. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...


People often use the words "regulator" and "demand valve" interchangeably, but here a demand valve is the part of a regulator that delivers gas to the diver's mouth and the first stage of the regulator is usually designed to release the gas at a constant rate from the cylinder despite the pressure in the cylinder becoming less as the gas in the cylinder is used.


For the history of the diving regulator see Timeline of underwater technology. Timeline of underwater technology // Pre-industrial Several centuries BC: (Relief carvings made at this time show Assyrian soldiers crossing rivers using inflated goatskin floats. ...

Contents


Parts of a diving regulator

The parts of a regulator are described in downstream order as following the gas flow from the cylinder to its final use.

A diving regulator A clamp type first stage
A diving regulator A clamp type first stage
A DIN first stage with 2 medium pressure and 1 high pressure hose
A DIN first stage with 2 medium pressure and 1 high pressure hose

Image File history File links Reg_firststage. ... Image File history File links Reg_firststage. ... Image File history File links Download high resolution version (1296x972, 118 KB) Summary Diving regulator first stage with a DIN cylinder attachment, 2 medium pressure hoses and a high pressure hose Licensing I, the creator of this work, hereby release it into the public domain. ... Image File history File links Download high resolution version (1296x972, 118 KB) Summary Diving regulator first stage with a DIN cylinder attachment, 2 medium pressure hoses and a high pressure hose Licensing I, the creator of this work, hereby release it into the public domain. ...

Fastening the regulator to the cylinder or cylinder block

In an open-circuit scuba set, the regulator, or its first-stage, has an A-clamp or a DIN fitting to connect it to the pillar valve of the diving cylinder. Two A-clamps as used in scuba gear An A-clamp is a type of clamp very often used to make a pressure-tight high-pressure fastening in scuba gear. ... A pillar valve is the type of cylinder valve which is commonly found fitted to scuba cylinders. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...


A-clamp

This is the traditional type. It clamps an open hole on the regulator against an open hole on the cylinder. The connection is made gas pressure tight with an O-ring. See A-clamp. Typical O-ring and application An O-ring is a loop of elastomer with a round (o-shaped) cross-section used as a mechanical seal. ... Two A-clamps as used in scuba gear An A-clamp is a type of clamp very often used to make a pressure-tight high-pressure fastening in scuba gear. ...


DIN fitting

This is a modern type of direct screw-in connection. See Diving cylinder for further information on DIN fittings. Deutsches Institut für Normung e. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...

A depth gauge and standard contents gauge
A depth gauge and standard contents gauge

diving regulator contents guage File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... diving regulator contents guage File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... A Depth Gauge is a device used to measure pressure and display the equivalent depth in water. ...

Pressure gauge

To monitor breathing gas pressure in the diving cylinder, a diving regulator usually has a high pressure hose leading to a contents gauge (also called pressure gauge). The port for this hose leaves the first-stage upstream of all pressure-reducing valves. The contents gauge is a pressure gauge measuring the gas pressure in the diving cylinder so the diver knows how much gas remains in the cylinder. It is also known as submersible pressure gauge or SPG. There are several types of contents gauge:- Many techniques have been developed for the measurement of reduced or increased pressures. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...


Standard type

This is an analogue gauge that can be held in the palm of a hand and is connected to the first stage by a high pressure hose. It displays with a pointer moving over a dial. Sometimes they are fixed in a console, which is a plastic or rubber case that holds the air pressure gauge and also a depth gauge and/or a dive computer and/or a compass. An analog or analogue signal is any continuously variable signal. ... Plastic covers a range of synthetic or semisynthetic polymerization products. ... Rubber is an elastic hydrocarbon polymer which occurs as a milky emulsion (known as latex) in the sap of several varieties of plants though can be produced synthetically. ... A Depth Gauge is a device used to measure pressure and display the equivalent depth in water. ... A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent rate can be calculated and displayed so that the diver can avoid decompression sickness. ... Compass in a wooden box A compass (or mariners compass) is a navigational instrument for finding directions on the earth. ...


Button gauges

These are coin-sized analogue gauges connected directly to the first stage. They are often used on decompression cylinders. Due to their small size, it can be difficult to read the gauge to a resolution of less than 20 bar / 300 psi.


Air integrated computers

Some dive computers are designed to measure and display and monitor pressure in the diving cylinder. This can be very beneficial to the diver, but if the dive computer fails, the diver can no longer monitor his or her gas reserves. Most divers using a gas-integrated computer will also have a standard air pressure gauge. The computer is either connected to the first stage by a high pressure hose, or has two parts, the pressure transducer on the first stage and the display at the wrist or console, which communicate by radio link; the signals are encoded to eliminate the risk of one diver's computer picking up a signal from another diver's transducer, or radio interference from some other source. A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent rate can be calculated and displayed so that the diver can avoid decompression sickness. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ... A dive computer or decompression meter is a device used by a scuba diver to measure the time and depth of a dive so that a safe ascent rate can be calculated and displayed so that the diver can avoid decompression sickness. ...


Mechanical reserve valves

In the past, some types of diving cylinder had a mechanical reserve valve that restricted air flow when the pressure was below 500 psi. Alerted to having a low gas supply the diver would pull a lever to open the valve and surface using the reserve gas. These valves are known as "J valves" due to the letter J being next to that valve in the US Divers product catalog. Valves without the reserve lever are called "K valves" for the same reason; being the next item in the catalog they were denoted by the letter K. Modern divers using "J valves" dive with the reserve valve in the open position and depend on a contents gauge or computer to monitor gas supply. US Divers is the Sporting Goods Division of Aqua Lung America, who make scuba diving equipment. ...

Diagram of the internal components of a piston-type first stage
Diagram of the internal components of a piston-type first stage
Diagram of the internal components of a diaphram-type first stage
Diagram of the internal components of a diaphram-type first stage

Image File history File links Diving_regulator_piston. ... Image File history File links Diving_regulator_piston. ... Image File history File links Diving_regulator_diaphragm. ... Image File history File links Diving_regulator_diaphragm. ...

First stage

The first stage takes gas from the diving cylinder at pressures of 200 - 300 bar (3000 - 4500 psi) and reduces its pressure down to 10 bar (150 psi) higher than ambient pressure in the medium pressure hoses. 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...


Types

The mechanism inside the first stage can be of the diaphragm type or the piston type. Both types can be balanced or unbalanced. A diaphragm first stage may be over-balanced as well. The performance of unbalanced regulators decreases as the cylinder pressure falls. A balanced regulator will keep the same ease of breathing at all depths and pressures. The over-balanced regulator will become easier to breath at depth.


Piston type

Piston-type first stages are simpler to make than the diaphragm type. They provide higher performance when breathed at depth. They need more careful maintenance because some of the internal moving parts are exposed to water and contaminants in the water.



With the piston-type first stage, the piston is rigid and acts directly on the seat of the valve. When the pressure in the medium pressure drops because the diver has used gas from a second stage valve, the piston lifts off the valve seat and slides towards the medium pressure chamber. This brings high pressure gas into the medium pressure chamber until the pressure in the chamber has risen enough to push the piston back onto the seat and close the valve.


Diaphragm type

Diaphragm-type first stages are more complex and have more components than the piston type. They are more responsive; they provide gas when the diver uses little inhalation effort.


The diaphragm is a flexible cover to the medium-pressure chamber. When the diver consumes gas from a medium-pressure second stage, the pressure falls in the medium-pressure chamber and the diaphragm collapses inwards pushing against the valve lifter. This opens the valve letting high-pressure gas pass the valve seat into the medium-pressure chamber. When the pressure in the medium-pressure chambers rises, the diaphragm inflates outwards reducing the force on the valve lifter, letting the spring behind the valve close it. A diaphragm is some sort of separating membrane. ...


Risk of the regulator becoming blocked with ice

As gas leaves the cylinder it decreases in pressure in the first stage, becoming very cold due to adiabatic expansion. Where the water temperature is less than 5°C any water inside the regulator may freeze, preventing the valve closing, causing a free-flow that can empty a full cylinder within a minute or two. Generally the water that freezes is in the ambient pressure chamber around a spring that keeps the valve open and not in moisture in the dry breathing gas from the cylinder. In thermodynamics, an adiabatic process is a process in which no heat is transferred to or from working fluid. ...


The modern trend of using more plastics, instead of metals, within the regulators encourages freezing because it insulates the inside of a cold regulator from the warmer surrounding water. Environmental sealing of the ambient pressure chamber and teflon coatings around springs are used to reduce the risk of freezing inside the regulator. Teflon is polytetrafluoroethylene (PTFE), a polymer of fluorinated ethylene. ...


Types of last stage

Not present

If there is only one stage, and that stage is constant flow, the gas must be turned on and off at the cylinder.


Manually operated valve

The diver uses a button or lever or knob to blow gas or air into a device, such as buoyancy compensators, drysuits, and many rebreathers. This type of valve is connected to the first stage with a medium pressure hose commonly called a "direct feed". (The valves on blowtorches are in this class also.) A buoyancy compensator (or buoyancy control device, BC or BCD) is a piece of diving equipment worn by divers to provide: life saving emergency buoyancy both underwater and on the surface. ... drysuits are used in a number of sports to provide a barrier between the occupant and cold water. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... The top torch is a welding torch and the bottom is a cutting torch, or blowtorch A blowtorch is a torch used to cut metal. ...

A diagram of the internal components of a demand valve
A diagram of the internal components of a demand valve

Image File history File links Demand_valve_labelled. ... Image File history File links Demand_valve_labelled. ...

Demand valve

A demand valve detects when the diver starts inhaling and supplies the diver with a breath of gas at ambient pressure.


The demand valve was invented in 1865 in France, and forgotten in the next few years, and was not invented again until the late 1930s. Timeline of underwater technology // Pre-industrial Several centuries BC: (Relief carvings made at this time show Assyrian soldiers crossing rivers using inflated goatskin floats. ...


The demand valve has a chamber, which in normal use contains breathing gas at ambient pressure. A valve which supplies medium pressure gas can vent into the chamber. Either a mouthpiece or a fullface mask is connected to the chamber, for the diver to breathe from. On one side of the chamber is a flexible diaphragm to control the operation of the valve. // Scuba diving and industrial breathing sets Nemrod twin-hose diving regulator made in the 1980s. ... A diver in a pool wearing an AGA full face mask A diver wearing an Ocean Reef full face mask A full-face diving mask is a type of diving mask worn by SCUBA divers so that they can talk with the surface or other divers. ... In mechanics, a diaphragm is a sheet of a semi-flexible material, anchored at its periphery, and most often round in shape. ...


When the diver tries to breathe in, the inhalation lowers the pressure inside the chamber, which moves the diaphragm inwards operating a system of levers. This operates against the closing spring and lifts the valve off it seat, opening the valve and releasing gas into the chamber. The medium pressure gas, at about 10 bar/140 psi over ambient pressure, expands, reducing its pressure to ambient pressure, blowing out any water in the chamber and supplying the diver with gas to breathe. When the chamber is full and the lowering of pressure has been reversed, the diaphragm expands outwards to its normal position to close the medium pressure valve when the diver stops breathing in.


When the diver exhales, one-way valves, made from a flexible and air-tight material, flex outwards under the pressure of the exhalation allowing gas to escape from the chamber. They close making a seal when the exhalation stops and the pressure inside the chamber reduces to ambient pressure.


The diaphragm is protected by being covered by a second chamber, which the outside water can enter freely through large holes or slits.


Some passive semi-closed circuit rebreathers use a form of demand valve, which senses the volume of the loop and injects more gas when the volume falls below a certain level.


Most modern demand valves use a downstream rather than an upstream valve mechanism. In a downstream valve, the moving part of the valve opens in the downstream direction and is kept closed by a spring. In an upstream valve, the moving part works against the pressure and opens in an upstream direction. In the event that the first stage jambs open and the medium pressure system over-pressurises, the second stage downstream valve opens automatically resulting in a "freeflow". With an upstream valve, the result of over-pressurisation may be a ruptured hose or the failure of another second stage valve such as one that inflates a buoyancy device.


Pressure relief valve

A demand valve serves as a fail safe for over-pressurisation: if a first stage with a demand valve malfunctions and jambs in the open position, the demand valve will be over-pressurised and will "free flow". Although it presents the diver with an imminent "out of air" crisis, this failure mode lets gas escape directly into the water without inflating buoyancy devices. The effect of unintentional inflation might be to carry the diver quickly to the surface causing the various injuries that can result from an over-fast ascent. There are circumstances where regulators are connected to inflatable equipment such as a rebreather's breathing bag, a buoyancy compensator or a drysuit but without the need for demand valves. Examples of this are argon suit inflation sets, and "off board" or secondary diluent cylinders for closed-circuit rebreathers. When no demand valve is connected to a regulator, it should be equipped with a pressure relief valve so that over-pressurisation does not inflate any buoyancy devices connected to the regulator. Fail-Safe (or Fail Safe for the 2000 version) is the title of: A 1962 novel by Eugene Burdick and Harvey Wheeler. ... Divers face specific physical and health risks when they go underwater (e. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... A buoyancy compensator (or buoyancy control device, BC or BCD) is a piece of diving equipment worn by divers to provide: life saving emergency buoyancy both underwater and on the surface. ... drysuits are used in a number of sports to provide a barrier between the occupant and cold water. ... General Name, Symbol, Number argon, Ar, 18 Chemical series noble gases Group, Period, Block 18, 3, p Appearance colorless Atomic mass 39. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ...


Valve operated by a solenoid

Fully closed circuit, electronic rebreathers have electronically controlled valves to inject fresh oxygen into the loop. The valve is opened with a solenoid in response to falling oxygen partial pressure detected by the electro-galvanic fuel cells that monitor the loop. These valves are connected to the first stage with a direct feed. See Rebreather#Fully closed circuit rebreather. Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... A solenoid is a loop of wire, often wrapped around a metallic core, which produces a magnetic field when an electrical current is passed through it. ... In Chemistry, the partial pressure of a gas in a mixture or solution is what the pressure of that gas would be if all other components of the mixture or solution suddenly vanished without its temperature changing. ... An electro-galvanic fuel cell is an electrical device used to measure the concentration of oxygen gas in SCUBA diving and medical equipment. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ...


Arrangements of the assembly of valves

Often one first stage supplies in parallel two or more second stages of various types. Each of these second stages should be looked for below according to its type.


Often a branch tube goes off without going through any pressure-reducing valve stages, to a pressure gauge. Many techniques have been developed for the measurement of reduced or increased pressures. ...


Types of regulator

Constant flow

In constant-flow regulators the first stage is constant flow, and the second stage is a plain on/off valve. (In a blowtorch the first stage is fastened to the cylinder and the second stage is on the torch head.) They are the earliest type of breathing set regulator. They are used now in many rebreathers. The only control the diver has is to open or close the second stage. Constant flow valves in an open-circuit breathing set consume gas less economically than demand valve regulators because gas flows even when it is not needed. The top torch is a welding torch and the bottom is a cutting torch, or blowtorch A blowtorch is a torch used to cut metal. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ...

Nemrod twin-hose regulator made in the 1980's. It has one low-pressure port, which feeds the left (inhalation) hose. Its mouthpiece can be strapped in.
Nemrod twin-hose regulator made in the 1980's. It has one low-pressure port, which feeds the left (inhalation) hose. Its mouthpiece can be strapped in.

In some rebreathers, e.g. the Siebe Gorman Salvus, the oxygen cylinder has two first stages in parallel. One is constant flow; the other is a plain on-off valve called a bypass; both feed into the same exit pipe which feeds the breathing bag. In the Salvus there is no second stage and the gas is turned on and off at the cylinder. Some simple oxygen rebreathers had no constant-flow valve, but only the bypass, and the diver had to operate the valve at intervals to refill the breathing bag as he used the oxygen. Image File history File links Download high resolution version (860x580, 93 KB)Nemrod twin-hose regulator made in the 1980s. ... Image File history File links Download high resolution version (860x580, 93 KB)Nemrod twin-hose regulator made in the 1980s. ... Nemrod is a Spanish firm who makes scuba gear. ... // Scuba diving and industrial breathing sets Nemrod twin-hose diving regulator made in the 1980s. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... CGI image: 2 views of a diver wearing a Siebe Gorman Salvus rebreather The Salvus is a light oxygen rebreather for industrial use (including by firemen and in coalmine rescue) or in shallow diving. ... In rebreather breathing sets, a bypass is a hand-operated valve that can be used to let more oxygen (or other breathing gas) into the breathing system, by-passing the cylinders flow rate control valve. ... Inspiration Closed Circuit Diving Rebreather Description A rebreather is a type of breathing equipment that provides a breathing gas containing oxygen and recycles exhaled gas. ...


With active semi-closed circuit rebreathers, the diver installs one of a number of different sized orifices in the valve before the dive. For safety reasons these should be chosen to provide more gas than the diver needs, to avoid hypoxia. Hypoxia is a pathological condition in which the body as a whole (generalized hypoxia) or region of the body (tissue hypoxia) is deprived of adequate oxygen supply. ...


Before 1939, diving and industrial open-circuit breathing sets with constant-flow regulators were designed and made, but did not get into general use due to excessively short dive duration for its weight. Design complications resulted from need to put the second-stage on/off valve where it could be easily operated by the diver. Examples were:-

Old-type "twin hose" Cousteau-type aqualung
Old-type "twin hose" Cousteau-type aqualung

Timeline of underwater technology // Pre-industrial Several centuries BC: (Relief carvings made at this time show Assyrian soldiers crossing rivers using inflated goatskin floats. ... Recreational diving is a type of diving that uses SCUBA equipment for the purpose of leisure and enjoyment. ... The Promenade des Anglais in Nice on the French Riviera at night. ... Old-type twin-hose aqualung This work is copyrighted, and used with permission. ... Old-type twin-hose aqualung This work is copyrighted, and used with permission. ...

Twin-hose

This is the first type of scuba demand valve that got into general use. This type of regulator has two (or occasionally one or three) stages in series in a large circular valve assembly mounted on top of the cylinder pack. The last (or only) stage is the demand valve.


In Europe and the USA, as officially made, twin-hose regulators were always fastened to the cylinder with an A-clamp. Two A-clamps as used in scuba gear An A-clamp is a type of clamp very often used to make a pressure-tight high-pressure fastening in scuba gear. ...


This type of regulator has two wide corrugated breathing tubes. The second tube was for breathing out through; it was not for rebreathing but to keep the air inside the breathing tube at the same depth pressure as the water outside the regulator diaphragm. This second breathing tube returns the exhaled air to the regulator on the wet side of the diaphragm, where it is released through a duck's-beak-shaped rubber one-way valve, and comes out of the holes in the wet-side cover. Nearly always in the mouthpiece assembly there are one-way valves to stop air or water going from the mouthpiece into the inhaling tube or from the exhaling tube into the mouthpiece. Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... Subfamilies Dendrocygninae Oxyurinae Anatinae Merginae For other uses, see Duck (disambiguation). ...


In Cousteau's first aqualung as first made, there was no second tube and the exhaled breath exited to the outside through a one-way valve at the mouthpiece. It worked OK on land, but when he tested the aqualung in the river Marne the air ran away when the mouthpiece was above the regulator. After that, he had the second breathing tube fitted. Jacques-Yves Cousteau in 1976. ... An aqua-lung (often spelt aqualung in the United Kingdom) is a type of SCUBA diving equipment consisting of a high pressure diving cylinder and a diving regulator that supplies the diver with breathing gas at ambient pressure. ... Marne is a département in northeastern France named after the Marne River which flows through the département. ...


Even with both tubes fitted, raising the mouthpiece above the regulator increases the flow of gas and lowering the mouthpiece increases breathing resistance. As a result, many aqualung divers put the loop of hoses under one arm to avoid the mouthpiece floating up causing free flow, when they were snorkelling on the surface to save air while reaching the dive site. Snorkeling is the practice of swimming at the surface of a body of water (typically of the sea) equipped with a mask and a short tube called a snorkel, to explore the underwater environment. ...

A "single-hose" aqualung with the first stage on top of the cylinder and the second stage demand valve on the left hand hose
A "single-hose" aqualung with the first stage on top of the cylinder and the second stage demand valve on the left hand hose

Divers had to carry more weight underwater to compensate for the bulk of air in the hoses. An advantage with this type of regulator is that the bubbles leave the regulator behind the diver's head, increasing visibility, and not interfering with underwater photography. They have been superseded by the single hose regulator and become obsolete for most diving in the 1980s. Download high resolution version (500x667, 26 KB)aqua lung This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... Download high resolution version (500x667, 26 KB)aqua lung This image has been released into the public domain by the copyright holder, its copyright has expired, or it is ineligible for copyright. ... car wreck in a lake A NikonosV underwater camera with flash and lanyard Underwater photography is the process of taking photographs while underwater. ... MacGyver - 1980s hero The 1980s decade refers to the years from 1980 to 1989, inclusive. ...


The original Cousteau twin-hose diving regulators could deliver about 140 litres of air per minute, and that was officially thought to be adequate; but divers sometimes needed a faster rate, and had to learn not to "beat the lung", i.e. to try to breathe faster than the regulator could supply. In 1948 to 1952 Ted Eldred designed his Porpoise air scuba to supply 300 litres/minute if breathed from that fast, and that soon became British and Australian naval standard. The litre or liter (see spelling differences) is a unit of volume. ... Ted Eldred was a pioneer of scuba diving in Australia. ... Porpoise is a tradename for scuba developed by Ted Eldred in Australia and made there from the late 1940s onwards. ... Navy is also:- shorthand for Navy Blue the nickname of the United States Naval Academy A navy is the branch of the armed forces of a nation that operates primarily on water. ...


Some modern twin-hose regulators have one or more low-pressure ports that branch off between the two valve stages, as direct feeds, as described under #Two stage, single hose below.


Someone made a twin-hose type regulator where the energy released as the air expands from cylinder pressure to the surrounding pressure as the diver breathes in, is not thrown away but used to power a propeller. To meet Wikipedias quality standards, this article or section may require cleanup. ...


The twin hose mouthpiece or fullface mask has reappeared in modern rebreathers, but as part of the breathing loop, not as part of a regulator. // Scuba diving and industrial breathing sets Nemrod twin-hose diving regulator made in the 1980s. ... A diver in a pool wearing an AGA full face mask A diver wearing an Ocean Reef full face mask A full-face diving mask is a type of diving mask worn by SCUBA divers so that they can talk with the surface or other divers. ... Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ...


Twin-hose, home-made

In 1956 and for some years afterwards in Britain, factory-made aqualungs were very expensive, and many aqualungs of this type were made by sport divers in diving clubs' workshops, using miscellaneous industrial and war-surplus parts. One necessary raw material was a Calor Gas bottled butane gas regulator, whose 1950's version was like an aqualung regulator's second stage but operated constant-flow because its diaphragm was spring-loaded; conversion included changing the spring and making several big holes in the wet-side casing. The cylinder was often an ex-RAF pilot's oxygen cylinder; some of these cylinders were called tadpoles from their shape. Timeline of underwater technology // Pre-industrial Several centuries BC: (Relief carvings made at this time show Assyrian soldiers crossing rivers using inflated goatskin floats. ... Calor Gas is a make of bottled butane which is available in Britain. ... Butane, also called n-butane, is the unbranched alkane with four carbon atoms, CH3CH2CH2CH3. ... The Royal Air Force (often abbreviated to RAF) is the air force branch of the British Armed Forces. ... Ten-day-old tadpoles Embryos (and one tadpole) of the wrinkled frog (Rana rugosa) A tadpole (also known as a pollywog) is a larval frog, toad, salamander, newt, or caecilian. ...


In least one version of Russian twin-hose aqualung, the regulator did not have an A-clamp but screwed into a large socket on the cylinder manifold; that manifold was thin, and meandered somewhat. It had two cylinders and a pressure gauge. There is suspicion that those Russian aqualungs started as a factory-made improved descendant of an aqualung home-made by British sport divers and obtained unofficially by a Russian and taken to Russia. Two A-clamps as used in scuba gear An A-clamp is a type of clamp very often used to make a pressure-tight high-pressure fastening in scuba gear. ... The word manifold has a variety of meanings. ...


Two stage, single hose

Most modern scuba regulators are of this type. Its main components are: a first stage, from which one or more medium pressure hoses run to various equipment listed below. The first make of this sort of scuba was the Porpoise (make of scuba gear) which was made in Australia. Porpoise is a tradename for scuba developed by Ted Eldred in Australia and made there from the late 1940s onwards. ...

A drysuit direct feed
A drysuit direct feed
A pair of demand valves
A pair of demand valves
A combined diving regulator demand valve and BC inflation valve
A combined diving regulator demand valve and BC inflation valve
diagram of the 1946 version of the Le Prieur breathing set
diagram of the 1946 version of the Le Prieur breathing set

Image File history File links Download high resolution version (1296x972, 115 KB) Summary Medium pressure direct feed of a diving regulator Licensing I, the creator of this work, hereby release it into the public domain. ... Image File history File links Download high resolution version (1296x972, 115 KB) Summary Medium pressure direct feed of a diving regulator Licensing I, the creator of this work, hereby release it into the public domain. ... diving regulator demand valve File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... diving regulator demand valve File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... diving regulator demand valve and bcd inflate File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... diving regulator demand valve and bcd inflate File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links Download high resolution version (1021x1679, 58 KB) Summary From French patent 922. ... Image File history File links Download high resolution version (1021x1679, 58 KB) Summary From French patent 922. ...

First stage valve

The first stage has a high-pressure "port" for the high-pressure hose to the pressure gauge. It has a number of "ports" for low-pressure hoses to carry gas to other components, which serve as second-stage valves of various sorts. All unused ports must be blanked off. Many techniques have been developed for the measurement of reduced or increased pressures. ...


With regulators that are used as breathing sources, at least one low-pressure hose connects to a demand valve. Some low-pressure hoses connect to the diving suit inflation valve and the buoyancy compensator inflation valves: these low-pressure hoses are called direct feeds. Two divers, one wearing a 1 atmosphere diving suit and the other standard diving dress, preparing to explore the wreck of the RMS Lusitania, 1935 A diving suit is a garment or device designed to protect a diver from the underwater environment. ... A buoyancy compensator (or buoyancy control device, BC or BCD) is a piece of diving equipment worn by divers to provide: life saving emergency buoyancy both underwater and on the surface. ...


Second stage valve

A second stage valve can be:-


Direct feed

A connection to inflate a buoyancy compensator or a drysuit, is manually operated by a button or lever or knob. A buoyancy compensator (or buoyancy control device, BC or BCD) is a piece of diving equipment worn by divers to provide: life saving emergency buoyancy both underwater and on the surface. ... drysuits are used in a number of sports to provide a barrier between the occupant and cold water. ...


Demand valve

This type of second stage is called demand valve or DV. It is fed by a medium pressure hose from the first-stage. It works as described in the Types of last stage section above. When the diver breathes out, the air goes to the dry side of the diaphragm, and is released to the outside through (usually two) one-way valves. It also has a purge button, which the diver can press to depress the diaphragm to make gas flow to blow water out of the mouthpiece (or for other purposes such as filling a lifting bag). A lifting bag is an item of diving equipment consisting of a robust and air-tight bag with strops, which is used to lift heavy objects underwater by means of the bags buoyancy. ...


Octopus

Sometimes (nowadays nearly always) a single-hose regulator has more than one demand valve (= DV). If the extra DV is simply a spare DV for use by the diver's buddy it is usually called an octopus. The medium pressure hose on the octopus is usually longer than the medium pressure hose on the DV that the diver uses. When using the buddy system, pairs and groups of three SCUBA divers dive together and co-operate with each other, so that they can help or rescue each other in the event of an emergency. ...


Combined DV and BC inflator

The demand valve could be a hybrid DV and buoyancy compensator inflation valve. Both types are sometimes called alternate air sources, and more confusingly a DV on a regulator connected to a separate independent diving cylinder would also be called an "alternate air source". A buoyancy compensator (or buoyancy control device, BC or BCD) is a piece of diving equipment worn by divers to provide: life saving emergency buoyancy both underwater and on the surface. ... 12 litre and 3 litre steel diving cylinders A diving cylinder or SCUBA tank is used to store and transport high pressure breathing gas as a component of an Aqua-Lung. ...


Full face mask

There have been at least two cases of a single-hose-type demand regulator last stage built into a circular fullface mask so that the mask's big circular front window plus the flexible rubber seal joining it to its frame, was a very big and thus very sensitive regulator diaphragm:- A diver in a pool wearing an AGA full face mask A diver wearing an Ocean Reef full face mask A full-face diving mask is a type of diving mask worn by SCUBA divers so that they can talk with the surface or other divers. ...

  • A version of the Le Prieur breathing set. Yves Le Prieur patented it in 1946 and the patent was granted on 10 February 1947.
  • Captain Trevor Hampton invented independently a similar regulator-mask in the 1950's and submitted it for patent, but the British Navy requisitioned the patent, but found no use for it and eventually released it, but by then the market had moved on and it was too late to make this regulator-mask in bulk for sale.

A patent is a set of exclusive rights granted by a state to a person for a fixed period of time in exchange for the regulated, public disclosure of certain details of a device, method, process or composition of matter (substance) (known as an invention) which is new, inventive, and... Captain Trevor Hampton was born in Birmingham in 1912 or 1913. ... The Royal Navy is the navy of the United Kingdom. ...

Dive/surface valve or bailout valve

A Dive/surface valve (DSV) or bailout valve (BOV) is a device in the mouthpiece on the loop of a rebreather which connects to a bailout demand valve and can be switched to provide gas from either the loop or the demand valve without the diver taking the mouthpiece from his or her mouth. An important safety device when carbon dioxide poisoning occurs. [1] Inspiration closed circuit diving rebreather A rebreather is a type of breathing set that provides a breathing gas containing oxygen and recycles exhaled gas. ... Hypercapnia is a condition where there is too much carbon dioxide (CO2) in the body. ...


Performance of regulators

In Europe, EN 250 defines the minimum requirements for breathing performance of regulators. ANSTI has developed a testing machine that measures the inhalation and exhalation effort in using a regulator; publication of results of the performance of regulators in the ANSTI test machine has resulted in big performance improvements. CEN, the European Committee for Standardization, was founded in 1961 by the national standard bodies in the European Economic Community and EFTA countries. ...


External links

  • First and Second stage service manuals - 4mb PDF

Manufacturers


  Results from FactBites:
 
Diving regulator - Wikipedia, the free encyclopedia (2968 words)
A diving regulator is such a regulator which is used in a scuba set and supplies its user with breathing gas at ambient pressure from one or more diving cylinders.
The original Cousteau twin-hose diving regulators could deliver about 140 litres of air per minute, and that was officially thought to be adequate; but divers sometimes needed a fster rate, and had to learn not to "beat the lung", i.e.
Someone made a twin-hose type regulator where the energy released as the air expands from cylinder pressure to the surrounding pressure as the diver breathes in, is not thrown away but used to power a propeller.
Diving cylinder - Wikipedia, the free encyclopedia (2809 words)
Diving cylinders are typically filled in the range of 186 to 300 bar (2700 to 4300 psi, or 18.6 to 30.0 MPa) and have a volume of 1.5 to 18 litres or a gas carrying capacity of 850 to 3600 litres (30 to 120 ft³).
Diving cylinders until the 1970s, before pressure gauges on regulators came into common use, often used a mechanical reserve mechanism to indicate to the diver that the cylinder was nearly empty.
In recreational diving for example, it is recommended that the diver plans to surface with a reserve remaining in the cylinder of 500 psi, 50 bar or 25% of the initial capacity, depending of the teaching of the diver training organisation.
  More results at FactBites »

 
 

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