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Last updateThu, 14 Dec 2017 8pm

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Process Instrumentation in Oil and Gas

Process Instrumentation in Oil and Gas

Process instrumentation is an integral p...

Check Valves in LNG Cryogenic Service

Check Valves in LNG Cryogenic Service

Because natural gas is currently conside...

Will Smart Machines Obsolete Human Resources?

Will Smart Machines Obsolete Human Resources?

Is artificial intelligence (AI) going to...

Is Valve Live Loading an Option?

Is Valve Live Loading an Option?

Valves leak. There’s no getting ar...

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Industry Headlines

EIA Forecasts Record U.S. Oil Output in 2018

Thursday, 14 December 2017  |  Chris Guy

The U.S. Energy Information Administration (EIA) estimates that U.S. crude oil production averaged 9.7 million barrels per day (b/d) in November, up 3...

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Construction and Mining: Is 2018 The Year for Growth?

Construction and Mining: Is 2018 The Year for Growth?

Tuesday, 12 December 2017  |  Kate Kunkel

While there is a degree of optimism in the mining industry that hasn’t been seen for some years, much uncertainty still exists in this sector. A...

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Industry Headlines

Setpoint I.S. Honored by Baton Rouge Business Report

11 HOURS AGO

Setpoint Integrated Solutions (Setpoint I.S.) was honored this fall at the Baton Rouge Business Report’s Top 100 Private Companies Luncheon. Celebrating its 35th Anniversary this year, the Baton Rouge Business Report hosts many events in the community.

At the most recent event , the Top 100 Private C...

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Emerson to Modernize Controls for Phoenix-Area Hydro Fleet

1 DAY AGO

Arizona-based Salt River Project (SRP), one of the nation’s largest public power utilities, has selected Emerson to modernize the controls of multiple hydropower units and its central service center. SRP provides electricity to 1 million customers in the metropolitan Phoenix area and is also one...

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EIA Forecasts Record U.S. Oil Output in 2018

7 HOURS AGO

The U.S. Energy Information Administration (EIA) estimates that U.S. crude oil production averaged 9.7 million barrels per day (b/d) in November, up 360,000 b/d from the October level. Most of the increase was in the Gulf of Mexico, where production was 290,000 b/d higher than in October. Higher pro...

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Chemical Industry Growth Rate Surpasses 20-Year Average

1 DAY AGO

The U.S. chemical industry is riding a global wave of growth as the world’s major economies experience an upswing for the first time in a decade. Increased output and accelerating growth rates that surpass the previous twenty-year average will help cement the business of American chemistry as ...

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U.S. Manufacturing Technology Orders Up 6.3%

1 DAY AGO

Orders for manufacturing technology kept their momentum in October 2017, gaining 6.3% over September to a total value of $428.32 million, according to the latest U.S. Manufacturing Technology Orders Report from The Association for Manufacturing Technology (AMT). Year to date, orders are up 7.6% comp...

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NAM Survey: Manufacturers’ Optimism Reaches Record High

2 DAYS AGO

The National Association of Manufacturers (NAM) released the results of the Manufacturers’ Outlook Survey for the fourth quarter of 2017, showing manufacturers’ optimism has risen to unprecedented heights amid the legislative progress made on tax reform. With 94.6% of respondents saying ...

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Actuation in Nuclear Power Plants

vmfall11_nuclear_h

The thousands of actuators used in a nuclear plant face some pretty tough conditions as well as rigorous testing.

Currently, 104 nuclear power-plant reactors are working in the United States, and all of them have operating environments that are extremely challenging. Of those 104 plants, 35 are classified as boiling and 69 as pressurized water reactors.

While the design details vary from plant to plant, each nuclear facility has thousands of valve actuators used in various processes and applications. The newest-generation nuclear plant has more than 13,000 valves.

It’s clear, then, that valve actuators play vital roles in maintaining process safety, efficiency and productivity in a wide range of situations.

This article contains a brief description of some of the special circumstances encountered in challenging nuclear environments and the different styles of actuators used to meet demanding operational and safety requirements.

STRICT GUIDELINES AND REQUIREMENTS

vmfall11_nuclear_electric_actuatorWith O-ring sealed covers in place on this electric actuator, the motor, limit and torque switches, as well as other electrical components, are housed within a pressure-tight enclosure. This keeps out dirt and moisture and prevents breathing from expansion and contraction of the internal air caused by temperature changes.All equipment used in nuclear plants built in the United States is certified under stringent guidelines mandated by the Nuclear Regulatory Commission (NRC). Verification of reactors or equipment to standards from other countries is not acceptable for the 104 working reactors in the U.S.

To understand basic requirements the nuclear power industry faces in this nation, a review of the similarities and differences between nuclear power and fossil power is helpful.

In a fossil power plant, coal might be crushed and mixed with air to boil water, which produces steam to drive a turbine. With nuclear reactions, the process is different, but the operational objective is essentially the same—to heat water to produce steam to drive a turbine. With a coal steam generator, the activity of burning the pulverized coal and producing steam is contained within what is termed the “boiler island.” Because of the strong similarity to what happens in the coal plant, many engineers and technicians in a nuclear plant refer to the area where steam generation occurs as the “nuclear island.”

vmfall11_nuclear_cutawayThis cutaway illustration shows the internal components of a typical electric actuator.Within the nuclear reactor, equipment must meet rigorous standards. Since radiation is very high, the standards require all equipment materials used in this phase of the process to withstand high levels of radiation for the life of the plant. Therefore, materials such as iron or steel are required rather than aluminum. Also, temperatures in this portion of the plant are elevated, which will affect seal materials. The combination of severe environmental conditions determines the various coatings and paints allowed for use in this area, which is known as “inside containment.”

To be suitable for service in a nuclear reactor, an actuator must go through specific testing by outside testing agencies. The test reports produced must then be reviewed not only by the actuator suppliers, but by consulting engineers and the utilities themselves. Many documents also are reviewed by the NRC.

The tests for actuators used “inside containment” apply to all styles. The plants use electric motor operators as well as pneumatic cylinder actuators and hydraulic cylinder actuators. All of these actuators must be tested to ensure they can withstand the environment for their expected lives. Also, in addition to environmental concerns, the actuators must be able to operate during extreme accident conditions such as an earthquake.

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