Global Valve and Controls = Pipe line Valves
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Global Valve and Controls
Our corporate office is located in Houston, Texas with stocking distribution locations throughout North America. Global Valve and Controls has serviced the industrial market for nearly a decade. Within this decade GVC has worked closely with many leading Oil & Gas, Energy, Petrochemical and Agriculture companies worldwide, providing valve flow control products of the highest performance and superior quality at competitive pricing.
GVC provides high performance industrial ball valves at competitive prices. We maintain a comprehensive in-house inventory of all our products ensuring your order is ready for immediate delivery.
The Overview of Long Pipeline Ball Valve
In the long pipeline system, the required pipeline ball valve must have the following functions such as controlling the medium, changing the direction of the medium flow, preventing reflux, cutting off the medium, blocking the pipe and so on.
In order to realize the above-mentioned functions, the long pipeline ball valve must be provided with the following features. Firstly, reliable sealability. The long-distance pipeline can only be checked at the regular time and sometimes it has to pass through high mountain, desert, grassland, earthquake region and other places. If the sealability is not good, it maybe will result in leakage or even the serious accident. Therefore, for preventing these things, this kind of valve must have the good sealability, especially for the sealiability of urgent grease injection. Secondly, the operation time should be long. Once the long pipeline ball valve is used, it can not stop working in several years or even in more than ten years. The longer it operates, the better it is. For prolong the service time, the valve seat is of great importance. Because to some degree it depends on the using time of the valve. Thirdly, the valve must have the high strength and resistance force. In the transportation process, the pressure of this valve may reach at 10.0MPa and the length may be very long. Therefore, it is easy to suffer the extending, curving or squeezing by the external forces such as earthquake, temperature or equipment vibration. In order to ensure the normal operation of the valve, enough strength is essential. Fourthly, the long pipeline ball valve should be resistant to corrosion. Because the natural gas contains the Hydrogen sulfide, which can erode the valve and eat the mechanical device, it is of great importance to select resistance-proof material. Fifthly, it has the automatic function. As we know, the long pipeline ball valve is controlled by the central control room. So in order to control the valve at the long distance immediately, the valve should be controlled automatically. Last but not least, the valve must be light in weight and tight in structure. With this feature, it is convenient to install and repair the valve.
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Find Out About Earthquake Gas Shutoff Valve
A natural gas seismic and an earthquake gas shutoff valve are the same devices. These devices are designed to automatically close the gas supply off to a home in the event of an earthquake of any significant magnitude happens. Some insurance companies require homeowners to install these valves before they will provide insurance on a home. Some municipal governments require you to install these shut-off valves, and some people simply install them for their own peace of mind. For people who do live in areas that are prone to earthquakes, placing one of these valves on the gas line will provide your family with extra safety in the event of an earthquake.
Before you go and purchase one of these valves for your home you need to get a measurement of the circumference on the gas line in your home to make certain that the valve you buy will fit. The majority of homes have a half an inch fitting, but this is not the case in all homes.
If you try to install the wrong size valves it simply will not work. You will have to have the correct valve for your gas line. Almost all the hardware stores in areas that are prone to earthquakes carry these valves, and they will carry both sizes.
Do not confuse these shut-off valves with gas flow valves that are designed to shut the gas off in case of a leakage. You can ask the personnel in the store for assistance in purchasing the correct valve. When you have everything you need assembled you need to shut the gas to your home off at the main.
You will need a pipe wrench to shut the main off. Place the wrench on the ball valve in the main and turn it one quarter of a turn. It does not matter which direction you turn in. If you are uncomfortable with shutting the gas off at your main, you can call your gas company and they will do this for you.
You will need to now tighten your pipe wrench around the union connection that is connecting your house to the gas meter. Loosen this union up and remove it from the pipe. Next you will remove the pipe nipple from the line. Now screw your shut-off valve onto the line on the house side until it is firmly fitted in the pipe, and the on/off indicator switch is perpendicular to the pipe itself. At this stage it is off.
You will now take your pipe nipple and put it back on the pipe on the house side. Then on the house side you will put that union back on the pipe. Now tighten that union where it connects to the gas meter. Apply some pipe compound onto the pipe threads to help seal the connection.
Check for leaks by taking some soapy water and placing it around your new valves and all other connections. Turn the gas back on and watch the soapy areas for bubbles. If you have bubbles you have leaks. No bubbles means you are good to go.
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Discover how an earthquake gas shutoff valve can save your life or the lives of your family now in our insider's review on gas shutoff devices on http://www.draincleaninggenie.com
Sample Pneumatic Components System Fabrication Techniques
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Size and weight do matter with NeSSI. Because our plan is to get the pneumatic equipment by-line (i.e., next to the sampling point), it's important that a system is small and light so that service can be done on a replacement basis. Today we have the ability to fabricate modular miniature systems that should be able to be assembled Lego-style by an unskilled person.
Yet in many cases we build modular systems that haven't been optimized for space or still require custom tubing work. We should aim to tightly integrate the modular system with its enclosure, to reduce size and weight, as well as eliminate custom tubing. Use of graphical indication of the flow paths certainly will overcome reluctance to use a densely populated sampling system.
Sample system design methodology. Software configurator tools available for designing NeSSI systems ultimately will expand to include the heaters, the microclimate enclosure, the wiring interconnections and the applets specified for the SAM. These tools will allow an end user to do a rapid detail design of a sample system based on company best practice and generate a detailed bill of materials and estimate.
Because the NeSSI bus is intrinsically safe, use of pre-certified components allows us to virtually self-certify our system as an entity regardless of where in the world the system is installed. The assembler or integrator now will be able to validate the automated performance and operation of the sample system as part of the check-out procedure by enabling self-checking routines available in the SAM. Contrast that to current designs where much of the detailed design is farmed out and systems are mainly checked only for mechanical operation.
Stream switching norms. For sample and calibration/validation fluid switching, we often use double-block-and-bleed stream-switching valves with bubbler systems to indicate a leak. This mandates maintenance rounds to regularly check if there's a leak at the bubbler. Use of miniature, modular close-coupled systems minimizes upswept voids; the need for double-block-and-bleed valves to reduce dead volume all of sudden becomes less important. Another reason for multiple valves has been to compensate for leaky valves that were standard fare in the "bad old days."
Early stream-select valves were ball valves with poor seating later followed by explosion-proof solenoid valves that probably were even worse. Today we have better valves (see "Streamline Your Sampling System,"
And if they leak smart flow and pressure sensors can monitor valve performance. Use of close-coupled systems and smart sensors allows us to simplify our systems and reduce size and costs by minimizing the need for double-block-and-bleed stream-switching hardware. This also frees us from the burden of providing visual indications of leakage.
Rotameter Replacement: NeSSI-bus-enabled
unit can sense fluid flow, pressure and temperature,
and serve in Division 1/Zone 1 areas.
Photo courtesy of Circor.
Use of visual indication devices such as rotameters and pressure gauges. We're addicted to their usage because we've felt a need to "see" the process fluid. However, as glass rotameters have given way to armored versions with magnetically coupled indicators, what we're getting now is an inferential view of the flow. The new NeSSI-bus-compliant flow devices can transmit flow or pressure signals.
If you have a signal that's available on a graphical user interface you really don't need an indicator. Maybe it's time to remove the windows from our sample system enclosures and get a smaller transmitter in their place. Eliminating the rotameter also does away with an aggravating position constraint that dictates vertical positioning of the sample system.
Use of manual flow and pressure regulators. A rotameter generally comes with a needle valve, allowing manual flow adjustment by analyzer technicians. So, how can we adjust flow without a rotameter? Work is underway to supply a proportional valve coupled to a flow or pressure transmitter to give a real control loop on the sample system. This will allow us to monitor the flow using proportional-integral-derivative (PID) control and also input a set point.
Consider the great strides gas chromatograph manufacturers have made with carrier-gas pressure controls. The days of matching flows using needle valves are history. Thankfully needle valves used in the majority of process gas chromatographs have been consigned to the obsolete parts bin.
Shows a NeSSI-bus-enabled valve control module for actuating sample-system pneumatic valves as well as a NeSSI-bus-enabled pressure/temperature transmitter. The module is rated Division 1/Zone 1 and so can be mounted inside a sample system enclosure. When used with a gas chromatograph it can obviate separate pneumatic tubes between the chromatograph and the sample system. A single cable connection links the gas chromatograph to the valve control module.
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Himfr.com Reports China Might Become Top World Exporter, But Weakness Remains
Algerian President Abdelaziz Bouteflika said here on Sunday that his country is willing to further develop the strategic cooperation relations with China.
During his meeting with visiting Chinese Foreign Minister Yang Jiechi, Bouteflika said Algeria is willing to enhance coordination and cooperation
with China on international affairs and work with China to boost the strategic cooperation relations.
Algeria and China always support each other and boast a special partnership based on mutual trust, the president said, adding that the two nations have witnessed progress in substantial cooperation in all areas and close cooperation on major international issues.
Amid deep evolution of the international situation, both Algeria and China have the political will to further develop bilateral relations, he said.
The China-Africa Cooperation Forum (CACF) and China-Arab States Cooperation Forum (CASCF) are beneficial to boosting China's relations with African countries and with Arab countries respectively, he said.
Algeria would like to help push forward China's relations with Africa and Arab countries, the president said.
Bouteflika also said that Algeria firmly adheres to the one-China policy and supports China in its reunification, noting that Algeria's stand in
this regard will never change.
The Chinese foreign minister said over the 51 years since China and Algeria established diplomatic ties, the two peoples have been supporting,
trusting and cooperating with each other.
Since entering the new century, Chinese President Hu Jintao and President Bouteflika have exchanged visits and established the strategic
cooperation relations, bringing China-Algeria relations to a period of best and quickest development in the history, Yang said.
China highly values Sino-Algerian traditional friendship and is willing to boost friendly communication, expand mutual beneficial cooperation,
enhance discussion and coordination on regional and international affairs and enrich the scope of bilateral relations to push forward the strategic cooperation relations to bear more fruit, Yang said.
He said, in recent years, the two countries have enjoyed frequent exchange of high-ranking visits and growing political mutual trust and have
worked together to safeguard the rights and interests of the developing countries on international affairs such as the climate change.
Moreover, the substantial cooperation in economic and trade and infrastructure construction fields have been deepened continuously, and the
exchange and cooperation within the frameworks of the CACF and CASCF have been expanded, said the top Chinese diplomat.
Also in the day, Yang held talks with his Algerian counterpart Mourad Medelci on bilateral relations as well as on major global and regional issues of common concern. Yang arrived in Algeria on Sunday on a two-day visit.
About the Author:
I am a professional editor from http://www.himfr.com/, and my work is to promote a free online trade platform.
http://www.himfr.com/ contain a great deal of information about Flanged Butterfly Valve,china agent,Illuminated Rectangular Push Button Switches, welc
Selecting A Butterfly Valve For An Application
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Butterfly Valve
Used as a primary control device in fluid transfer applications, butterfly valves are preferred over most other types of valves for different reasons. Firstly, they perform a quarter-turn open/close operation, which is frequent, quick, and at less fluid resistance. Second, they display good flow control for a wide range of liquids, gases, suspended solids, and slurries. Lastly, they are compact, lightweight, and available in a wide range of materials, too.
The wastewater treatment, pharmaceutical, power generation, paper processing, food & beverage, and fine chemical industries utilize butterfly valves extensively. PTFE lined (FEP / PFA) valves are used in high corrosive chemical environments, whereas hygienic valves made from special types of elastomers are used in the food & beverage industry. Butterfly valves also come in fire safe designs to meet the safety requirements of the petrochemical industry.
Typically, butterfly valves come in sizes ranging from 1 to over 200. Their pressure capabilities range from 150 psi to 750 psi. Available in manual and automatically actuated modes, they are used as an on/off as well as controlling/modulating device. The seat material, body style (wafer or lug), and stem- design play crucial roles in selecting a butterfly valve.
Selecting the Right Style:
The most common types of body designs or mounting styles in butterfly valves are the wafer, lug, semi-lugged, and double flanged styles. While the wafer design is cheaper and safer, the lug style helps in removing downstream piping. Wafer styles attribute to the lightweight structure of butterfly valves, which ensures ease of installation.
Selecting Stem Designs:
The stem or shaft of a butterfly valve comes in one-piece or two-piece designs. While selecting a stem design for a high performance application, one must be aware of the fact that they have to be in contact with the fluid media and hence media compatible.
Selecting the Right Seat Material:
Being critical elements, seals, or seat materials, also determine the quality of a butterfly valve. A variety of factors, including chemical compatibility, pressure, temperature, cost, and wear is considered prior to selecting seats. PTFE (Polytetrafluroethylene) and RTFE (Reinforced Polytetrafluroethylene) are two commonly used seat materials known for their abrasion resistant, electrical insulation, and thermal properties. UHMWPE (Ultra-high Molecular Weight Polyethylene) is another popular material with excellent corrosion and chemical resistance used in the tobacco industry. The material is also ideal for low-radiation environments.
If the application involves a highly abrasive environment, inflatable seats that offer high wear resistance are used. Today, many applications require butterfly valves with FDA approved seat materials. Fire-safe, metal-seated butterfly valves are also popular choices today.
Selecting the Right Type of Butterfly Valve:
Butterfly valves are classified into three types based on their construction:
1. Resilient
2. High Performance
3. Tricentric
The resilient type of butterfly valves uses the rubber flexibility and hence used widely in applications that require lowest pressure ratings. They handle temperatures ranging from 25F to 300F. High-pressure applications use high performance types of butterfly valves as these valves provides a wear-free sealing. Temperature ratings for these valves range from 400F to 450F. Tricentric designs feature a metal seat, which can withstand tremendous amount of pressure and temperatures up to 1000F.
Selecting the Right Valve Size:
We can determine the right valve size by calculating the Flow Coefficient (Cv) of the butterfly valve. You can use the below formula to calculate the Cv:
Cv = GPM / √ΔP
Here, GPM is the max flow requirement and P is the maximum pressure drop. The valve size that is equal to the calculated Cv value is the correct size. If the needed Cv value is between two valve sizes, the larger valve size is selected.
About the Author:
Ron Bargman is a regular contributor of manufacturing-theme articles drawing on his decades long experiences first as an owner of an auto-parts supplier and manufacturer, to his present status as the founder and president of Zycon, an internationally recognized search engine for manufacturers. Ron's rich industry history provides insight into manufacturing and engineering news and events that are timely, poignant and relevant.
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