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Survey Shows Small Business Confidence Increasing

Thursday, 27 April 2017  |  Chris Guy

The second annual Allstate/ Small Business Barometer finds increasing optimism and innovation among small business owners, despite the rising cost of ...

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Industry Headlines

Metso Providing Valves for Oman Petrochemical Complex

20 HOURS AGO

Metso will supply 400 Neles emergency shutdown (ESD) valves for an ethylene cracker as part of the new Liwa Plastics Industrial Complex (LPIC) Project in Sohar, Oman. The new complex will process light ends produced in Orpic's Sohar Refinery and its aromatics plant as well as optimize natural gas li...

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Curtiss-Wright Earns Safety Award for Third Year in a Row

20 HOURS AGO

A Curtiss-Wright facility located in Chanhassen, MN, received a Governor’s Safety Award for superior performance in workplace safety and health as part of the Minnesota Governor’s Safety Awards. The Chanhassen site produces Exlar electric actuators and earned this award by reporting better...

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East Coast Refiners Eye Texas as Alternative to North Dakota

16 HOURS AGO

“Major U.S. East Coast refiners profited from railing hundreds of thousands of barrels of discounted Bakken crude to their plants daily from 2013 until 2015. But as more and more pipelines were built in North Dakota, the discount began to disappear, and so did the rail cars,” Reuters repor...

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Wind Energy Growing Nine Times Faster Than Overall Economy

1 DAY AGO

American wind power added jobs over 9 times faster than the overall economy amid robust growth for another year, according to the American Wind Energy Association (AWEA), which just released its annual report. Installing over 8,000 MW of new wind power for a second straight year, the U.S. industry inv...

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Survey Shows Small Business Confidence Increasing

-1 DAYS AGO

The second annual Allstate/ Small Business Barometer finds increasing optimism and innovation among small business owners, despite the rising cost of doing business. Nine in 10 local entrepreneurs say the benefits of owning a business outweigh the challenges. This year’s Barometer found that, ...

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Durable Goods Orders Up 0.7% in March

-1 DAYS AGO

New orders for manufactured durable goods in March increased $1.6 billion or 0.7% to $238.7 billion, the U.S. Department of Commerce announced today. Economists were anticipating an increase of 1.2%. This March increase , the third consecutive, followed a 2.3% February increase.

Excluding transportatio...

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A Guide to Valve Cleaning and Specifications

Most of the time we only require that valves be free of basic dirt and debris before they are put in service. However, occasionally service requirements dictate that all traces of oil, dust and grease be removed. A prime example is valves to be used with oxygen. In that case, even a small speck of oil in a 100% oxygen environment can create a devastating explosion. One tiny metallic sliver could cause a minute spark, which is all that would be required to trigger the destruction.

 

Other media that require this level of cleanliness include numerous other pure gases, chlorine, paints and some chemicals. What all this means is that a standard, off-the-shelf valve cannot be used in these media unless it has been properly processed before installation. Decades ago, achieving this degree of cleanliness required the use of vapor degreasing machinery filled with a chlorinated solvent such as trichloroethane. These chemicals worked marvelously to clean, but they have been proved to be carcinogens, so their industrial cleaning usage has all but disappeared. In their place, environmentally friendly aqueous-based cleaners, such as Simple Green, have become the norm.


Follow the Specs

Even with the use of the right cleaning agent, however, it takes more than a simple “wash behind the ears” to ensure that a valve is clean enough for intended service. This is where cleaning standards and specifications come in. Fortunately, there are very good specifications to guide valve assemblers and technicians in the cleaning process. In fact, the American Society for Testing and Materials (ASTM) has a committee that works solely on specifications for oxygen service applications: Committee G04. This group produces ASTM G93, “Standard Practice for Material and Equipment Used in Oxygen-Enriched Environments,” which is a very thorough document and an excellent reference for valve cleaning procedures.

The Compressed Gas Association (CGA) publishes another often referenced cleaning standard: document CGA G-4.1, “Cleaning Equipment for Oxygen Service.” Many end-users that don’t have their own specific procedure reference the CGA 4.1 standard. The Manufacturers Standardization Society (MSS) also recently created a valve cleaning standard, MSS SP-138-2009, “Quality Standard for Oxygen Cleaning of Valves & Fittings.” This document is derived from many end-user specifications as well as CGA G-4.1. For chlorine service cleaning, the Chlorine Institute references cleaning procedures in its document: “Piping Systems for Dry Chlorine.”

The common denominator for all the cleaning standards is removal of all traces of oils, grease, dirt and other contaminants. The methods prescribed include scrubbing, ultrasonic cleaning, pressure blasting and sand blasting.


Rust Elimination

One important issue in cleaning is the presence of rust on carbon steel components after cleaning. With any of the prescribed cleaning processes, the protective film or rust preventative on the steel is removed, which exposes the metal to rapid oxidation, a problem that is particularly acute in humid environments. In many cases, a light blush of rust is acceptable, but gross deposits would not be. As a result, cleaning may need to be performed in a non-humid area. Additionally, carbon steel valves and components that have been cleaned require some form of corrosion protection—either desiccant bags inserted in the valve bore or an exterior wrapping with vapor phase inhibitor paper, or both.

After valves have been carefully cleaned and checked for proper cleanliness, they are usually put in protective heavy-gauge plastic bags to ensure they stay clean until installation.

Cleaning of valves is a straight-forward process that requires some diligence and quality control. However, guidance is available from various standards and specifications. Also, since the valves must be disassembled for most cleaning procedures, it’s important that the personnel involved be familiar with proper disassembly and re-assembly of the valves to be cleaned.

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Greg Johnson, a contributing editor to Valve Magazine, is president of United Valve (www.unitedvalve.com), which offers factory-authorized valve modifications and repair from its Houston, TX facility. Reach him at This email address is being protected from spambots. You need JavaScript enabled to view it..

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