Issue link: https://geospatial.trimble.com/en/resources/i/1415432
Spring 2019 75 7 V alve actuators are critical to the safe and effi cient operation of tank farms, as they are to almost every other part of the hydrocarbon supply chain. Actuators must perform reliably and accurately at all times, often in demanding environments, so it pays to choose them with care. This article explains how modern electric actuators meet the needs of fl ammable liquids storage. On tank farms, valve actuators are primarily used for controlling hydrocarbon streams for storage and blending. However, tank farm applications for electric actuators also include fi re protection systems, wastewater treatment and site utilities. Over the last decades, electric valve actuators have proven to be a reliable and effi cient solution for automating the valves needed in all of these applications. First of all, electric actuators are easy to install as they need only an electrical supply to operate. Unlike pneumatic or hydraulic systems, the actuator is virtually maintenance-free. Low operational and maintenance costs are clearly important in tank farms, which often have several hundred actuators (Figure 1), and electric actuators have the advantage of a comparatively low total cost of ownership. Electric actuators are typically equipped with powerful built-in electronics as well as interfaces to communicate with plant control systems. They also provide intelligent diagnostics that facilitate effi cient asset management. Actuators are available that meet safety standards for hazardous atmospheres, and often provide functional safety and fi re safety too. Their robust design and effective corrosion protection allow them to withstand very high or very low temperatures, high humidity, and the often highly saline atmospheres found in tank farms located close to the sea. Reliable flow control Most tank farm operators are service providers that do not own the crude oil or fuel they store. Only by delivering the required service within the time constraints can they make a profi t. Individual transfers involve complex sequences of pump and valve operations, with no time for mistakes or Joachim Toffolo, AUMA, Germany, explores how electric actuators in tank farms can take valve automation to the next level.