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Last updateFri, 29 Apr 2016 5pm

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Food and Beverage Processing

Food and Beverage Processing

When wandering the grocery store aisles,...

Variable Frequency Drives in Electric Actuators

Variable Frequency Drives in Electric Actuators

Electric actuators are vital for operati...

Braided Packing: An Old Technology with a Modern Twist

Braided Packing: An Old Technology with a Modern Twist

Compression packing is the primary metho...

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Industry Headlines

Rotork Acquires Mastergear from Regal Beloit

2 HOURS AGO  |  Chris Guy

Rotork has acquired the entirety of Mastergear’s business and assets from Regal Beloit Corporation for $25 million on a cash-free and debt-free ...

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Industry Headlines

Rotork Acquires Mastergear from Regal Beloit

2 HOURS AGO

Rotork has acquired the entirety of Mastergear’s business and assets from Regal Beloit Corporation for $25 million on a cash-free and debt-free basis and a value of inventory that will be finalized at the end of a transition service agreement.

Mastergear will become part of Rotork's Gears divis...

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Emerson Opens New Helix Innovation Center

23 HOURS AGO

Emerson announced the launch of its “Helix” initiative, including the opening of The Helix innovation center, an industry-first, $35 million hub dedicated to advancing research and education for the global heating, ventilation, air conditioning and refrigeration (HVACR) industry. The new ...

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Energy Sector Weighs on Construction Starts

23 HOURS AGO

At a seasonally adjusted annual rate of $660.5 billion, new construction starts in March receded 1% from February’s pace, according to Dodge Data & Analytics. Total construction starts had jumped 13% in February, led by a huge gain for the electric utility and gas plant category. The dolla...

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Chevron Investing Billions in The Permian Basin

2 DAYS AGO

At Chevron’s annual security analyst meeting last month, chairman and CEO John Watson said that his company plans on investing billions into oil & gas projects in the Permian Basin.

According to the Hobbs News-Sun , Watson predicted they could be pumping up to 350,000 barrels a day out of West ...

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House Passes Bill To Lower Import Tariffs On Manufacturers

1 DAY AGO

This week, the House voted 415-2 for the American Manufacturing Competitiveness Act of 2016. The bipartisan, bicameral bill reforms the way Congress considers legislation for suspending tariffs on products not made in the U.S., what some are calling, “manufacturing tax breaks.” The legis...

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Texas Manufacturing Index Shrinks More Than Forecast

3 DAYS AGO

Texas factory activity increased for a second month in a row in April, according to business executives responding to the Texas Manufacturing Outlook Survey. The production index, a key measure of state manufacturing conditions, rose from 3.3 to 5.8, suggesting a slight pickup in output growth.

Perce...

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Solenoid Valves

sum11_b2b_solenoid_introSolenoid valves are usually considered an accessory in the process valve industry; however, while there is some truth to this, these accessories are crucial to the proper operation of any system that uses them.

The solenoid valve has many features that need to be considered when creating a specification. Eight specification points should be addressed to correctly choose the right solenoid valve for an application. These specification points are:

  • Type
  • Operation
  • Media
  • Size
  • Pressure
  • Atmosphere
  • Voltage
  • Extras

More information on these eight points is included in this article.


TYPE

sum11_b2b_fig1Figure 1. 2-way solenoid valves used to start and stop the flow of media in a pipe trainThe type of solenoid valve refers to whether that valve is a 2-way, 3-way or 4-way. A 2-way valve (Figure 1) has two port connections-a pressure or input port (port 1) and an outlet port (port 2). These valves are used to stop the flow of a fluid or start the flow of a fluid in a piping configuration. Usually, a 2-way valve is referred to as a 2/2 valve, which means the valve has two ports and two positions. The positions are: 1) on or energized and 2) off or de-energized.

Three-way valves (Figure 2) are those that have three ports-a pressure or inlet port (port 1), a cylinder port (port 2) and an exhaust port (port 3). A 3-way valve’s most common application is for process valve automation. The solenoid valve sends air to a spring return actuator or cylinder, which creates rotational or linear movement to open or close a process valve. In this case, the media is usually compressed air or gas that is creating work, which is where the term “fluid power” is derived. The power of a compressed gas or pressurized liquid is controlled to create mechanical work. Three-way valves are usually referred to as 3/2 valves-they have three ports and two positions.

sum11_b2b_fig2Figure 2. Basic 3- and 4-way valves typically used for process valve automationFour-way valves (Figure 2) can have four or five ports-a pressure or inlet port (port 1), two cylinder ports (ports 2 and 4), and one or two exhaust ports (port 3 and possibly a port 5). The exhaust ports can either have both cylinder ports sharing a common exhaust port or have each cylinder port with its own exhaust port. This valve’s primary use is also for process valve automation. For double-acting or non-spring return actuators and cylinders, a 4-way valve must be used. Air flow in a 4-way valve is more complicated than air flow in some other types. For example:

  • In cases where the valve is de-energized or off: The pressure port to cylinder port 2 is open while cylinder port 4 to exhaust is open.
  • In cases where the valve is energized or on: The pressure port to cylinder port 4 is open while cylinder port 2 to the exhaust is open.

Since the actuator or cylinder does not have a spring on one side, it must rely on fluid power from a 4-way valve to open and close. Four-way valves can be referred to as 4/2 or 5/2 valves, and they can have four or five ports and two positions.

There are other configurations such as the dual solenoid, fail-in-last-position, 3/3, and 5/3 solenoid valves, but explanations are best left for another article.

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