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Ninety percent of survey respondents expect to buy these products in the next 12 months, and they’re looking for high reliability and ease of maintenance, says Mark Hoske.
Market for control valve actuators is growing, with 90% expecting to buy the same or more such products in the next 12 months as in the past year, according to research from Control Engineering andReed Corporate Research.
For users of control valve actuators, reliability, repeatability, and low maintenance are the most important features, the research showed, no doubt because the majority of the work is done in house when actuators need repair or service. Electric and pneumatic actuators are used about equally, at just over 40% of respondent locations. Primary applications for control valve actuators are food and beverage; chemical; industrial and other machinery; and other manufacturing and processes. Pharmaceutical and petroleum/refining applicationsalso make the list.
Among those specifying, recommending, and/or buying control valve actuators, 79% do so for inplant requirements and 34% buy for OEM needs. Broken down to reflect combined use, 13% buy both for OEM and in-plant use, 21% purchase only forOEM use, and 66% only for in-plant use.
The combination of continuous and batch manufacturing is the most prominent application (46%) of control valve actuators at respondents’ locations. “Continuous manufacturing only” is applied at 22% of locations.“Batch manufacturingonly” is used at 16%.Respondents mentionliquids as the media mosthandled by control valves,62%; air/gases 31%;slurries 4%; and powder3%.
Electric and pneumatic type actuators are used about equally at respondent locations, 42% and 41% respectfully, with manual about 16%. Also, the predominant choice is to have the actuator integrated with the valve (one assembly) at 76%, with the remaining 24% adding the actuator separately.
Among a variety of control valve types, pneumatic type actuators were used most often, 76%. Manual and electric type actuators were used less than pneumatics with all valve types. For most valve types, electric actuators were used more than manual. selling the most control valve actuators to respondents over the last 12 months. Purchases from the remaining manufacturers are split among numerous companies, with a dozen in double-digit percentages (see products from leading companies below).
Areas of growth
An ARC Advisory Group (www.arcweb. com) survey supports Control Engineering subscribers’ prediction of growth. The September 2006 study, Control Valve Worldwide Outlook, also covering actuators and positioners, estimates global growth in control valve shipments, from $3.5 billion in 2005 to more than $4.5 billion in 2010. ARC noted, “Hardware revenues are resurgent, fueled by the explosive growth in new projects, particularly in Asia. Growth is also strong in the oil & gas industryespecially with growing thirst for energy.”
Spring-returned diaphragmactuators
Emerson’s Fisher springreturned line of diaphragm actuators for control valves provides dependable on-off or throttling operation for many applications. Configurable spring rates, travel stops, and manual operators are available for most control valve uses. A molded diaphragm is said to have excellent linearity between loading pressure and resulting travel and yield high thrust output. The actuators exhibit a high degree of dynamic stability and frequency response in providing accurate, quick-acting valve control. Featuring rugged thick-wall cast iron and steel construction, they provide increased stability, corrosion protection, and protection against deformation should over-pressurization occur. They come in direct or reverse acting configurations and are suited to a variety of sliding stem and rotary valves.
www.fisher.com
Emerson Process Management
Don’t service this actuatorfor 10 years
ABB’s Contrac electric actuator provides 
intelligent or “smart” modulating action to position the control valve precisely within its operating range in response to a 4-20 mA dc control signal. Different-sized models are available for torque requirements ranging from 80 to 12,000 ft lb. Start-up torque is 1.2 times rated with “break-away” torque being twice the rated torque. These actuators can have fast stroke speeds that provide fast response to needed changes in valve position. Speeds are expressed in seconds for a 90° travel of the actuator lever arm. The actuator has oil-lubricated spur gearing in a sealed, dust-tight enclosure for high operating efficiency, high torque outputs with lower electric motor horsepower, and a 10-year maintenance cycle for an oil change.
www.abb.com/instrumentation
ABB
Remote operationintelligent positioner
The Foxboro SRD991 Intelligent Positioner, from Invensys Process Systems, is said to provide easy configuration and operation of pneumatic valve actuators from local and remote locations. Available with multiple communications protocols, including HART, FOUNDATION fieldbus, or Profibus-PA, the SRD991 is certified for installations involving explosive atmospheres and can be mounted on rotary or linear actuators. It operates from control systems, controllers, or PC-based configuration and operation tools – including FDT software. Available for single or double acting applications, it offers IP65 and NEMA 4X protection, is approved for SIL applications, and is intrinsically safe according to ATEX and FM/CSA.
www.foxboro.com/instrumentation
Invensys/Foxboro
Positioner reduces compressed air use
A unique feature of Sipart PS2 valve positioner from Siemens is its extremely low air consumption. When balanced, the PS2 consumes virtually no air, reducingelectricity costs by $120 per year per valve when compared to conventional designs, bydecreasing compressed air use. Sipart PS2controls the final element of pneumatic linearor part-turn actuators, where the positionermoves the actuator to a valve positioncorresponding to the setpoint. Additionalfunction inputs can be used to block thevalve or set a safety position. A binary inputis present as standard in the basic device forthis purpose. PS2 communicates througheither Profibus PA or HART protocols andcan also be operated through a MicrosoftWindows-based HMI (human machineinterface) with simple PC software.
www.automation.siemens.com
Siemens Automation & Drives
Electronic valve position sensor
The IND dual proximity switch from ifm electronic provides direct signalling of process valve open/closed status without the need for cumbersome and expensive switch boxes. In addition to simpler installation and adjustment, the new switch offers improved reliability, better environmentaltolerance, and installation cost savings.
The switch comprises two independent proximity sensors adjacently mounted in a single package. The sensors, one of which detects valve open, the other valve closed, are operated by small target discs fitted directly to the actuator shaft. This means that the cams, brackets and wear-prone electromechanical switches previously associated with valve position sensing are eliminated.
To allow existing plant to be easily upgraded, the IND switches have fixing holes spaced at 30mm, the same as the majority of switch boxes. In most cases, conversion to high-reliability, completely electronic sensing takes only a few minutes for each valve.
www.ifm-electronic.com
IFM Electronic
