- Published on Thursday, 17 April 2014 12:46
- Written by Tim Bremner
In many engineering sectors, application environments for polymer-based materials are expanding into ever higher temperatures, differential pressures and increased corrosive chemical attack. Consequently, end users and material providers must address the need for improved or new materials that will meet these demands, which is no small feat.
In this article, we will consider the generically classified “high-performance polymers” (HPPs) that include such material families as polyaryletherketones, polyphenylene sulphides, polyimides, polyamideimides and polyphenylsulphones. These are all commonly selected as the primary polymer type for components used in highly demanding environments.
- Published on Monday, 31 March 2014 12:05
- Written by Jose Veiga
The continuous improvement of valve packing technology has created a new baseline for the industry to achieve emission levels that previously were possible only with the use of bellows seals. To develop low emission valve packing and bonnet gaskets, it is necessary to have testing devices that simulate the actual service conditions while the critical parameters are monitored. This article summarizes several testing devices available to the help valve manufacturers engineer products that reduce emissions and meet new standards set by EPA consent decrees.
- Published on Monday, 24 March 2014 10:00
- Written by Loren Stewart
While many people might recognize the term “functional safety” and assume they know what it means, for the purposes of standards, the term itself needs explanation. Finding an understanding and complying with functional safety standards play a vital role in everyone’s safety. Breaking down what it is and why it matters are the first steps to full comprehension of functional safety and, ultimately, a safer world.
- Published on Monday, 17 March 2014 11:24
- Written by Blake Coleman
Maximum ethylene production requires several conditions: a highly saturated feedstock, high coil outlet temperature, low hydrocarbon partial pressure, short residence time in the radiant coil, and rapid quenching of the cracked gases. Out of these, cracked gas quenching is the only condition occurring downstream of the furnace, and is one of several steps that must occur before hydrocarbon fractionation occurs.
- Published on Monday, 10 March 2014 22:40
- Written by Kate Kunkel
The theme of VMA’s 2014 Technical Seminar and Exhibition event was “Valve Emissions for Compliance, Standards and Technology” and the presenters covered the subject from every angle. Keynote speaker Ken Garing is with the U.S. Environmental Protection Agency – NEIC – and opened the event with a comprehensive report on why it is so important to monitor and reduce fugitive emissions.
- Published on Monday, 24 February 2014 10:53
- Written by Leon Berckenhoff
With the rapid development of unconventional shale plays throughout the U.S. has come the challenge of transporting product to refiners and markets. The large number of wells and the high volume of natural gas being produced has led to an increase in the size and number of gathering and other midstream pipelines.
- Published on Monday, 10 February 2014 11:05
- Written by Roy Stevenson
Through-wall leakers in cast valve bodies often can be the end result of undetected defective areas created during the metal casting process. Such failures in service are extremely undesirable for valve manufacturer as well as the end user and in many cases such failures could pose significant health and safety concerns.
This article details the challenging nature of defect detection as related to through-wall leakers in typical cast pressure containing units. A discussion of common casting defects and the limitations of common defect detection methods or nondestructive evaluation (NDE) is provided. Finally, casting process simulation is described and presented as a means of detecting and eliminating the casting defects that commonly lead to the failure of valve castings.
- Published on Monday, 13 January 2014 20:00
- Written by Blake Coleman
Olefin production plants use a variety of feedstocks. The type of feedstock used will impact the type of recovery technology used, but no matter the feedstock, control valve performance is an essential part of plant operations.
In this, the first of a three part series, critical control valve applications in the furnace section will be discussed. There are alternative product recovery configurations, which include front-end de-ethanizer for plants utilizing light feedstocks and front-end de-propanizer for plants using heavier feedstocks, but the focus in this article is on the front end de-methanizer configuration because of its ability to allow for a variety of feedstocks.
- Published on Monday, 06 January 2014 13:43
- Written by Bob Caldwell
Specifying and consulting engineers, engineering houses, original equipment manufacturers (OEMs) and end users depend on valves to control the flow of compressed air or other fluids and on cylinders to control motion. But the cold truth is that low temperatures can cause problems for these fluid automation devices all along the line—from selection and delivery to operation and maintenance.
- Published on Monday, 16 December 2013 13:43
- Written by Loyd Hilliard
The relatively recent rise in demand for liquefied natural gas, or LNG, has fueled a boom with regards to the construction of import and export terminals. Since the early 1990’s the number of LNG exporting/importing countries has increased from 16 to 43. Couple this with the fact that large natural gas deposits are rarely located next to the huge arenas that consume them and you have the perfect storm that is the current LNG market.
- Published on Monday, 02 December 2013 10:42
- Written by Nathan Smith
All water distribution systems have one thing in common: It takes energy to move water from one location to another. The energy required to move the water can come from gravity or from pumps, both of which convert the water’s potential energy into kinetic energy. In a typical water distribution system, control valves are used at some point to manage this built-up energy, otherwise known as flow and pressure.
As water travels through a control valve, energy within the water is simply ‘burned off’ in the forms of noise, heat and vibration. Conduit hydropower installations aim to recover this lost energy by converting it into electricity while still regulating flow and pressure in a distribution system.