TPi January 2018

Valves , f i t t ings , f langes & connectors

Keeping plant control systems informed of manual valve positions

Refinery operators have a pressing requirement to improve the efficiency of flow control in their plants and they want to know from the distributed control system (DCS) if valves are open or closed. In a typical refinery, ten per cent of valves are actuated and 90 per cent are manually operated. This poses a problem for end-users if the DCS does not accurately know how many manual valves are opened or closed, which limits the efficiency of their business operations. To meet this challenge, Rotork Gears has introduced the SPI smart position indicator, designed to provide an improved, robust, reliable and accurate solution compared to previously available equipment. With an SPI installed, the control centre is able to monitor any of the valves in the refinery, so operational control is more accurate. The innovative solution has led a Spanish end-user to place an order for approximately 900 units. The SPI has a large dial display to show the valve position locally, and one or two internal switches or sensors for remote indication. The fully sealed aluminium enclosure provides an accurate and reliable valve position signal. For larger valves that are operated with a gearbox, the SPI is mounted to the gearbox input flange. For smaller valves it can be mounted directly on the valve, and an optional thrust base is available

The Rotork Gears SPI smart position indicator provides an accurate and reliable valve position signal for remote indication

available. The SPI is easy to maintain, and in case of failure the valve remains available. In addition to chemical and petrochemical plants, typical areas of application for the SPI include power stations, public infrastructures, airports and fire hydrant systems. Rotork plc – UK information@rotork.com www.rotork.com

for rising stem applications. The SPI uses the same ISO 5210 valve adaption as used for electric actuation, which is more robust than alternative ‘arm’ methods. Environmentally sealed to IP67, the SPI is available in two IECEx/ATEX Ex certified variants for hazardous areas: an Ex e ‘increased safety’ version for gas and dust applications, and an Ex i ‘intrinsic safety’ version for gas only. A non-certified safe area version is also

Protecting equipment and the environment Alfa Laval has introduced the spring- loaded Safety Valve, designed to protect both equipment and people. In a potentially dangerous situation, the valve will open at a pre-determined pressure. The compressed spring force keeping the valve closed is forced open when pressure builds up at the inlet of the safety valve. As these forces balance out, the valve will discharge and decrease pressure, ultimately reclosing as the system returns to normal. Key features include dedicated and reliable protection against accidents; calibration to the desired pressure set point, sealed and delivered with a PED certificate; and a hygienic design that eliminates unsanitary leaks and overflow during and after pressure peaks. The company has also introduced a range of Alfa Laval Scandi Brew anti-vacuum and overpressure valves. These safety valves protect against overpressure in tanks and pipelines, eg from overfilling or fermentation processes. They also protect against implosion, for example due to a vacuum caused by cold rinsing after hot cleaning, or blocking of gas supply during emptying. Alfa Laval – Sweden info@alfalaval.com www.alfalaval.com

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January 2018 TUBE PRODUCTS INTERNATIONAL