Valve actuation in extreme conditions

Flow of both oil and gas requires precise actuation of valves under extreme conditions – very high, very low temperatures, in arid or high rainfall environments, in remote situations in deserts or arctic tundra, while rebuffing the corrosive effects of high humidity or salinity for extended periods. Operating in explosive atmospheres, even with the potential to require fireproof operation. 

Pipeline operations depend for their fundamental functions on a high degree of valve automation. The complex processes in compressor stations, in pumping stations or on filtration skids require valve positioning to be accurate and extremely reliable.

Control of liquids and gas valves

Actuators have to control flow of both gas and liquids. Typically, ball or butterfly valve actuation requires part-turn actuators providing a swivel movement. Gate valves, on the other hand, typically need multi-turn actuators providing several complete actuator turns to operate the valve from open to close and vice versa. 

Open/close and modulating actuation

Both open-close and modulating actuation is required. Actuators for open-close duty are typically required to infrequently open or close shut-off valves, usually ball or butterfly types, in block line valve stations or scraping stations, for example. Pipeline applications often involve opening and closing large valves with, consequently, very high torque requirements. AUMA actuators address this with a portfolio of gearboxes, achieving torques of up to 675,000 Nm.

Modulating actuators provide enhanced positioning accuracy for control valves in order to precisely control the flow within pipelines. E.g., in gas receiving terminals in gas pipelines, pressure control valves have to operate frequently and precisely to reduce the gas pressure.

AUMA’s modular actuator concept meets varied demands with a set of standard components, reducing inventory requirements. A broad range of multi-turn and part-turn actuators are available for different torque ranges, for different power supply sources, different valve attachments, etc. A choice between basic or intelligent actuator controls provide cost-efficient solutions for both simple and the most complex process control tasks. Flexible actuator geometry allows easy on-site adjustment of mounting positions so that operating elements such as local controls and display are always easily accessible, even if space is scarce.

Actuator protection in corrosive and explosive environments

Especially important for pipeline situations exposed to highly saline atmospheres, AUMA employ a powder coating process for the individual housing parts. AUMA actuators meet the requirements of EN ISO 12944-6 for corrosivity categories C5-M long (marine, coastal and offshore areas).

Electric actuators to be used in oil and gas pipelines must be certified for use in potentially explosive atmospheres. The oil & gas industry is a global market with varied certification depending on the country or region, for example ATEX (Europe), IECEx, FM (USA), EAC (Russian Federation) or NEPSI (China). Additional requirements can call for actuators in fireproof versions that reliably maintain all functionality, even under the direct impact of fire. AUMA actuators can be equipped with a fireproof enclosure that meets the requirements of UL 1709 that absorbs the heat and ensures reliable actuator operation at ambient temperatures up to 1,100 °C for 30 minutes, preventing spread of fire by closing the valve.

Industrial Internet of Things (IIoT) and the intelligent actuator

The actuator also forms the crucial interface between the process and the distributed control system (DCS). And, as IIoT gains momentum, electric actuators provide direct access to a wide variety of both process and diagnostics data. AUMA's AC .2 controls can significantly save money at the system design stage by converting and transmitting data to the DCS, including from other sensors so wiring can be simplified.

IIoT and big data means that flow of oil and gas, the processes along the pipeline, will all be expressed as data with ever increasing granularity. Where there is data, that data can be used and manipulated, and new ways of using that data will emerge. Actuators, because they are present throughout any distributed flow process, will be key enablers in the data revolution to come.