Tap (valve)

Valves of this type using a cylinder rather than a cone are sometimes encountered, but using a cone allows a tight fit to be made even with moderate manufacturing tolerances. The numeric character references in HTML and XML are "G" and "g" for upper and lower case respectively. A hole through the cone allows the fluid to pass if it is lined up with the openings in the socket through which the fluid enters and leaves; turning the cone using the handle rotates the passage away, presenting the fluid with the unbroken surface of the cone through which it cannot pass. The EBCDIC code for capital G is 199 and for lowercase g is 135. A cone valve consists of a shallowly-tapering cone in a tight-fitting socket placed across the flow of the fluid. The ASCII code for capital G is 71 and for lowercase g is 103; or in binary 01000111 and 01100111, correspondingly. They can be identified by their range of only 90º between fully-on and fully-off - usually when the handle is in line with the pipe the valve is on, and when the handle is across the pipe it is closed. In Unicode the capital G is codepoint U+0047 and the lowercase g is U+0067.

Cone valves are usually found in gas taps (and, incidently, the cask beer taps referred to above). The rest of Spanish speakers did not follow him, but his works, and the translations of Rabindranath Tagore made by Jiménez's wife Zenobia Camprubí, are published in his spelling. In the UK this type of tap normally has a wheel-shaped handle rather than a crutch or capstan handle. The Spanish poet Juan Ramón Jiménez proposed to simplify the Spanish spelling by using just the versions with j. There is no resistance to flow when the tap is fully open, but this type of tap rarely gives a perfect seal when closed. In Spanish, G before I or E is pronounced as the same as J. Gate valves use a metal disc the same diameter as the pipe which is screwed into place perpendicularly to the flow, cutting it off. In Italian, GH is used to force a /g/ value before E and I where G would take a soft value, and GN is used for /ɲ/ (rather like English NY in canyon).

For high pressure domestic water systems this does not matter, but for low pressure systems where flowrate is important, such as a shower fed by a storage tank, a "stop tap" or, in engineering terms, a "gate valve" is preferred. GN, with value /n/, is also common, as in sign. This is called a "globe valve" in engineering and, while it gives a leak-proof seal and good fine adjustment of flow, the tortuous S-shaped path the water is forced to follow offers a significant obstruction to the flow. It now has a great variety of values, including /f/ in enough, /g/ in loan words like spaghetti, and silence in words like eight and night. Most taps use a soft washer which is screwed down onto a seat in order to stop the flow. GH originally represented the letter yogh which English adopted from Old Irish, and took various values including /g/, /ɣ/, /x/, and /j/. One reason that most beer taps are not designed for adjustable flow is that the beer itself is damaged by the pressure drop in a choked-flow valve: holding a beer tap partially open causes the beer to foam vigorously, ruining the pour. Several digraphs are common in English.

At very low flow settings, the viscosity of the water becomes important and the pressure drop (and hissing noise) vanish; at full flow settings, parasitic drag in the pipes becomes important and the water again becomes quiet. The general rule is that soft G is pronounced the same as the J of the same language. Bubbles of cool water vapor form and collapse at the restriction, causing the familiar hissing sound. Most non-Romance languages pronounce G as /g/ regardless of position (however the Dutch language does not have a /g/ sound in its native words, and instead G is pronounced /ɣ/, a sound that does not occur in English) while in Romance languages the soft value varies, such as /ʒ/ in French, Catalan, and Portuguese, /ʤ/ in Italian, and /x/ in Spanish. At intermediate flow settings the pressure at the valve restriction drops nearly to zero from the venturi effect; in water taps, this causes the water to boil momentarily at room temperature as it passes through the restriction. Generally, G is soft before E, I, and Y, and hard otherwise, but there are many English words of non-Romance origin where G is hard regardless of position, and two (gaol and margarine) in which it is soft even before an A. The choked flow rate is independent of the viscosity or temperature of the fluid or gas in the pipe, and depends only weakly on the supply pressure, so that flow rate is stable at a given setting. In some words of French origin, as in French generally, the "soft G" is pronounced as IPA /ʒ/, as in rouge, beige, and genre.

Turning the knob or working the lever sets the flow rate by adjusting the size of an opening in the valve assembly, giving rise to choked flow through the narrow opening in the valve. In English, the letter can be pronounced as a "soft G" (IPA /dʒ/), as in: giant, ginger, geology, or as a "hard G" (IPA /g/), as in: goose, gargoyle, game. Most water and gas taps have adjustable flow. The 1949 Principles of the International Phonetic Association recommends using for advanced voiced velar plosives and for regular ones where the two are contrasted, but this suggestion was never accepted by phoneticians in general, and today is the symbol used in the International Phonetic Alphabet, with acknowledged as an acceptable variant. Although a gas tap may be a valve that releases any gas, the word is most commonly used to refer to taps that control the flow of natural gas in the home (for gas fires) or in school science laboratories (for Bunsen burners). Generally, the two minuscule forms are interchangeable, but occasionally the difference has been exploited to make a contrast. A "beer tap" now may be one of several items:. And in the looptail version, there is a tiny flick at the upper right which in typography is called its "ear.".

This may be because the word was originally coined for the wooden valve in traditional barrels. The looptail version became popular when printing switched to "Roman type" because the tail was effectively shorter, making it possible to put more lines on a page. While in other contexts, depending on location, a "tap" may be a "faucet", "valve" or "spigot", the use of "tap" for beer is almost universal. The initial extension to the left was absorbed into the upper loop. This convention applies in the UK too, but many installations exist where it has been ignored. The looptail form developed similarly, except that some ornate forms then extended the tail back to the right, and to the left again, forming a loop. In some countries there is a 'standard' arrangement of hot/cold taps: for example in the United States the hot tap is generally on the left. The opentail version derives from the majuscule (capital) form by raising the serif that distinguishes it from a C to the top of the loop, thereby closing the loop, and extending the vertical stroke downward and to the left.

Mixer taps may have a red-blue stripe or arrows indicating which side will give hot and which cold. The modern minuscule (lower-case) G has two basic shapes: the "opentail G" and the "looptail G" . The cold tap generally has a blue or green indicator and/or is labeled C or Cold. As the sound /k/ did, /g/ also developed palatal and velar allophones which is why today, G has different sound values in all Romance languages, as well as English (due to French influence). In English-speaking countries, the hot tap generally has a red indicator and/or is labeled H or Hot. The recorded inventor of the letter G is Spurius Carvilius Ruga, who taught around 230 BC:. If separate taps are fitted, it may not be immediately clear which tap is hot and which is cold. The letter G was created by the Romans because they felt that C was not an adequate letter to represent both /k/ and /g/.

Latest designs do this using a built in thermostat. . This is a single, more complex, valve whose handle moves up and down to control the amount of water flow and from side to side to control the temperature of the water (achieved by mixing the hot and cold water together). Its name in English is gee (IPA [ʤi:]). In kitchens, and in the US and many other places, mixer taps are often used instead. G is the seventh letter in the Roman alphabet. Water for baths, sinks and basins can be provided by separate hot and cold taps; this arrangement is common in the UK, particularly in toilets. G is an abbreviated nickname of Andrew G.

. In economics, G is usually used to represent government spending or government expenditure. In American English the usage is sometimes more specialised, with the term tap restricted to uses such as beer taps and the word "faucet" used for water outlets; although some Americans use "tap" in the broader sense as well. In television, G is the TV Rating that stands for General, meaning the program is appropriate for everyone. For example, in Commonwealth English the word is used for any everyday type of valve, particularly the fittings on bathtubs and sinks. In sexology, the G-spot is also a part of the vagina that allegedly causes an orgasm when stimulated. A tap is a valve for controlling the release of a liquid or gas. In radiocommunication, G is one of the ITU prefixes allocated to the United Kingdom.

In an analogy to controlling the flow of a fluid, tap can also refer to drawing electricity from a certain winding in an electrical transformer. In psychometrics, g (always in lowercase) is the symbol for general intelligence. To tap a vessel containing liquid metal is to remove the liquid from the vessel, even if no valve as such is utilised in the process. In the United Kingdom, G stands for Glasgow. In Canada, G stands for the eastern part of Quebec. As the first letter of a postal code,