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History of the valve | | 
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Maybe inspired by the Beaver, early man, learned to regulate the flow of streams and rivers by blocking them with fallen trees or the use of large stones. Nobody can know for sure just when valves were first used. In Britain they were most likely introduced sometime after 43 A.D. when the Romans reached our shores. |
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Many early civilizations had developed water systems, early Egyptian and Greek societies devised several types of primitive valves to divert water for public consumption or crop irrigation. The diaphragm valve traces its origins back to ancient Greek times, where it was used to control the water level and temperature of the hot baths. Having a crude leather diaphragm that manually closed over a weir it was a primitive but effective control valve. |
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Greece has a very low source of natural, consumable water. The water was gathered in many ways. From natural pools of water, which acted as a reservoir and also cisterns, constructed to catch the rainwater and act as storage bins. If water was ever scarce using these methods aqueducts were used, which tapped into wells and underground streams. From this source of water many cities and towns were able to get enough water to function and use as a decoration. The water was so scarce that the Acropolis had a secret staircase that descended in a deep reservoir that held water piped from other springs. This reservoir was constructed to ensure that there would be enough water if the city were attacked. |
| It is the Romans, however, who are credited as the creators of highly developed water systems, but Rome had absorbed engineering techniques from the previous generations of every country that it had conquered, in particular from the Greeks. | | Roman plumbing was sophisticated enough to deliver water into individual buildings, for which they developed the plug valve, or stopcock, and there is also evidence that the Romans used check valves to prevent backflow. The word "plumbing" comes from the Latin term "plumbus" which means, "lead," early pipe and conduit was made from wood or earthenware. | 
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| The roman plug valves were made of bronze and three pieces compound it, body, plug, and bottom plus a lever to turn the plug. Here is a large valve which is housed in the Ostia museum of ancient Rome It is one of the largest known valves. It is still attached to large pipelines by heavy welds, which the Roman workmen so expertly accomplished. |
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| | There were no great advances in valve design until the rise of the Industrial Revolution although we do have sketches from the 15th Century by Leonardo da Vinci when he was designing a system of canals and locks. | 
| various valves and a pneumatic pump |
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| In 1698 Thomas Savery patented the first crude steam engine, he later worked with Thomas Newcomen on the atmospheric steam engine. James Watt filed his first engine patent in 1769. The first Watt engines put out only about 6 horsepower. But, in less than 20 years, he'd built engines that delivered as much as 190 horsepower. |
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Steam was picking up those specialized tasks that were absolutely essential for the Industrial Revolution to take place - like pumping water out of mines. Steam was positioning itself to power the really heavy industries that would so change 19th-century life. The pressures built up by steam had to be contained and regulated so valves acquired an important new role. And as James Watt and other inventors improved upon Newcomen's steam engine, designers and manufacturers also improved upon the valves used for these steam engines. |
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In 1829 At the Rainhill Trials to find a steam locomotive for the Liverpool to Manchester railway, George Stephenson's 'Rocket' was a clear winner, this was in part due to improvements made to the valves that enabled more accurate control of the amount of steam entering the cylinders. In later years rather then being designed as a specialized product to suit a particular project we would see valves manufactured on a large scale available as an off the shelf item for todays very diverse market. |
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