Valve History - CGIS
Valve History - CGIS
Valves have come a long way from their beginnings, almost years ago. Technological advancements and human knowledge have continuously allowed new and improved designs to emerge in the valve industry. Technological advancements are paired with the need for valves to be better suited for the applications as industries need enhanced valves. Historically, there are five critical eras of valve innovation, starting from years ago and leading up to the current day. We will take a trip down memory lane and cover these eras and the advancements made during them.
Rome
Roman civilization was no stranger to early engineering advancements. The availability of freshwater was restricted in ancient civilizations, but Rome found solutions to thrive. Rome is famous for its development of aqueducts which would move large volumes of water over a significant distance. Distribution of water became a responsibility of the Roman government, which was solved with the installation of waterworks system of lead pipe and bronze plug valves. These plug valves were simple shut-off valves fabricated from bronze castings. Along with the municipal water systems, these plug valves were also attached to individual homes and businesses. These valves connecting to an individual&#;s residence were seen as a symbol of luxury, as something not many people could afford direct water access. Check Valves were found in roman civilization as well. Hero of Alexandria invented a portable fire pump that could be rapidly deployed to fight fires. The manual operation of this pump relied on two check valves.The Industrial Revolution
The Industrial Revolution began in England in the late s and significantly impacted valve design and manufacturing. The boom in manufacturing and material production allowed valve manufacturers to expand their operations and improve their designs. New inventions like the steam engine were generating demand for valves that could handle higher pressures and temperatures. Valves used for waterworks remained relatively low pressure, while steam applications continually increased operating pressures. In , the Watts steam engine ran using 15 PSIG steam, by , operating pressures had reached over 200 PSIG.World War I
World War I brought standardization into the valve industry. The need to supply water to soldiers living in trenches and underground bunkers meant that as the trench lines moved, the water supply system had to be easily disassembled and re-configured and needed to be quickly repaired when damaged by artillery fire. Industry-standard groups had risen in the past years and influenced the standards that valves would be governed by. These groups include: &#; American Society for Testing and Materials (founded in ) &#; American Water Works Association (founded in ) &#; American National Standards Institute (founded in ) Pipe sizes were rationalized with the framework of these groups, which ultimately led to flange and pipe thread dimensions being standardized. Nearly all present-day valve types incorporate materials and design changes that began with standardization in the to era. Technological improvements brought cast steel as the most common material for industrial valves, which have much higher pressure and temperature ratings than bronze cast valves.World War II
World War II significantly increased the need for industrial valves. Refining oil to produce fuel for military purposes and synthetic rubber production ramped up during the war years, with refineries running at ever-increasing pressures and temperatures. US production of petroleum products grew from 3.5 million barrels of oil per day in to 4.8 million barrels per day in . The ever-increasing pressures and temperatures of oil production sparked the development of corrosion and heat-resistant metallic alloys. Along with this, the invention of pressure-seal bonnets was designed in response to high pressures and temperatures in steam applications. The final key invention of this time was Teflon, which was an accidental discovery in . Teflon has properties that make it ideal for many valve applications. It is chemically inert, can operate up to 500 °F, has very low friction and can be molded into complex shapes. Teflon was the final ingredient needed to bring valves into the nuclear age.-
The biggest improvements during this era revolve around control systems improving with computers. Sensors would feed data to computer control systems at high accuracy, much faster than traditional monitoring. Electric actuators sped up the system as well, phasing away from pneumatic control. This was particularly useful to the booming industry of nuclear power, where speed was of the utmost importance. In s, the triple-offset butterfly valve design was introduced. The design included a resilient seat that offers zero leakage, with a metallic body and seat capable of operating at temperatures far above any available polymer or elastomer butterfly valve seats. During the s and s, more improvements to controls systems were designed. There was a shift from analog control to digital control, which allowed for more complicated process control systems. These control systems led to more robust valves with sophisticated digital electronic control systems. Particularly, fieldbus communication systems allow operation and control of automated valves, which substantially cut the time to operate.With competitive price and timely delivery, Yaxing Valve sincerely hope to be your supplier and partner.
Gate valve
A gate valve, also known as a sluice valve, is a valve that opens by lifting a barrier (gate) out of the path of the fluid. Gate valves require very little space along the pipe axis and hardly restrict the flow of fluid when the gate is fully opened. The gate faces can be parallel but are most commonly wedge-shaped (in order to be able to apply pressure on the sealing surface).
Typical use
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Gate valves are used to shut off the flow of liquids rather than for flow regulation, which is frequently done with a globe valve. When fully open, the typical gate valve has no obstruction in the flow path, resulting in very low flow resistance.[1] The size of the open flow path generally varies in a nonlinear manner as the gate is moved. This means that the flow rate does not change evenly with stem travel. Depending on the construction, a partially open gate can vibrate from the fluid flow.[1]
Gate valves are mostly used with larger pipe diameters (from 2" to the largest pipelines) since they are less complex to construct than other types of valves in large sizes.
At high pressures, friction can become a problem. As the gate is pushed against its guiding rail by the pressure of the medium, it becomes harder to operate the valve. Large gate valves are sometimes fitted with a bypass controlled by a smaller valve to be able to reduce the pressure before operating the gate valve itself.
Gate valves without an extra sealing ring on the gate or the seat are used in applications where minor leaking of the valve is not an issue, such as heating circuits or sewer pipes.
Valve construction
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Common gate valves are actuated by a threaded stem that connects the actuator (e.g. handwheel or motor) to the gate. They are characterised as having either a rising or a nonrising stem, depending on which end of the stem is threaded. Rising stems are fixed to the gate and rise and lower together as the valve is operated, providing a visual indication of valve position. The actuator is attached to a nut that is rotated around the threaded stem to move it. Nonrising stem valves are fixed to, and rotate with, the actuator, and are threaded into the gate. They may have a pointer threaded onto the stem to indicate valve position, since the gate's motion is concealed inside the valve. Nonrising stems are used where vertical space is limited.
Gate valves may have flanged ends drilled according to pipeline-compatible flange dimensional standards.
Gate valves are typically constructed from cast iron, cast carbon steel, ductile iron, gunmetal, stainless steel, alloy steels, and forged steels.
All-metal gate valves are used in ultra-high vacuum chambers to isolate regions of the chamber.[2]
Bonnet
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Bonnets provide leakproof closure for the valve body. Gate valves may have a screw-in, union, or bolted bonnet. A screw-in bonnet is the simplest, offering a durable, pressure-tight seal. A union bonnet is suitable for applications requiring frequent inspection and cleaning. It also gives the body added strength. A bolted bonnet is used for larger valves and higher pressure applications.[3]
Pressure seal bonnet
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5 Things to Know Before Buying a flow control valve is also called
What is the difference between 304 and 316 stainless steel make it from?
Another type of bonnet construction in a gate valve is pressure seal bonnet. This construction is adopted for valves for high pressure service, typically in excess of psi (15 MPa). The unique feature of the pressure seal bonnet is that the bonnet ends in a downward-facing cup that fits inside the body of the valve. As the internal pressure in the valve increases, the sides of the cup are forced outward. improving the body-bonnet seal. Other constructions where the seal is provided by external clamping pressure tend to create leaks in the body-bonnet joint.
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Knife gate valve
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For plastic solids and high-viscosity slurries such as paper pulp, a specialty valve known as a knife gate valve is used to cut through the material to stop the flow. A knife gate valve is usually not wedge shaped and has a tapered knife-like edge on its lower surface.[4]
Images
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A 2&#; stainless steel gate valve with flanged ends. Bolts connect the lower valve body with the upper &#;bonnet&#;. Visible threads on the valve stem protruding above the handwheel show that this is a rising-stem valve.
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Inconel gate valve casting
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Cryogenic 254 SMO gate valve
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Cryogenic super duplex gate valve frozen up during operation
- Nuts and bolts for incoloy valves
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Gate valve being installed on a new water service to a fire hydrant . The valve material is ductile iron
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Gate valves
See also
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References
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