11/6/2015

With over 200 years' experience in supplying fluid handling equipment, SPX's Plenty brand provides a wide portfolio of products including leading simplex, duplex, backwashing and self cleaning strainers. These strainers are widely used in many industries including the power industry. The Plenty brand is synonymous with highly reliable, robust, long-lasting products. Once installed, a Plenty strainer will work reliably for many years and is designed to minimise maintenance costs while offering exceptional performance.
Plenty simplex and duplex strainers are widely used by the power industry in areas such as on raw water intake, cooling water lines and lube oil systems to protect turbines, heat exchangers, pumps and other valuable equipment from damage caused by unwanted debris. Both types of strainers are available with quick release covers that do not require additional tools and have large cross-sectional basket areas to minimise maintenance frequency. As well as increasing the running time between cleaning, the large basket area also lowers the pressure drop across the strainer, reducing pump effort required. The baskets are designed in two pieces with a replaceable insert, enabling easy change of mesh size and hence the level of filtration. To ensure operations continue to run smoothly and to optimise maintenance, the strainers can also be fitted with differential pressure gauges or switches for local operator indication or for signalling to wider control systems to alert when the vessel is getting near to blinding. Reinforced support baskets are also available to withstand high differential pressures.
Plenty duplex strainers have two filtration chambers with an integral flow changeover valve, enabling baskets to be cleaned and replaced without any interruption to flow and ensuring that one of the chambers is always in operation for continuous service. A wide range of models is available to suit differing flows and pressures with standard sizes from 1" to 36". The range offers many different features and options including automatic valve changeover operation. The Plenty H-Type duplex strainer can further be cast or fabricated for higher working pressures.
SPX Plenty strainers can be expertly customised and fabricated to exact application requirements in a wide choice of materials including stainless steel, duplex and super duplex. The need for high flows, bespoke flanges or covers, fabricated baskets, special differential pressure connections or paint systems can all be supplied.
Designed specifically for water applications the Plenty Q15 fully automatic backflushing strainer can be installed in any power plant using river, lake, canal, well or seawater for cooling, descaling, spraying, quenching, boiler feed or similar purposes.
The Plenty backflushing strainer is cleaned automatically, without interruption of the liquid flow, by utilizing the pressure within the system. An independent supply of clean water is not required.
In operation raw water enters the strainer inlet and passes through the holes in the tube plate into the tubular wedge-wire strainer elements where all contaminate larger than the element slot openings is retained inside the tubes. This continues until either the timer initiates the regular cleaning cycle or sufficient contaminate has accumulated inside the strainer tubes to restrict the flow passage causing an increase in the differential pressure. When the D.P. reaches a pre-set figure the automatic cleaning mechanism is actuated (over-riding timer) and a sliding seal plate connected to the backwash outlet effectively blanks off each strainer element in turn from the raw water supply. Pressure within the strainer body being higher than the pressure in the backwash outlet pipe induces a flow of clean water in the reverse direction through the isolated element effectively flushing away all accumulated debris to atmosphere and thus to waste.
This whole operation is controlled automatically by an adjustable timer with a differential pressure switch over-ride. When all the strainer tubes have been cleaned the backflush cycle stops and the strainer of actions in the normal way until either the D.P. switch or the timer actuates the cleaning cycle again. The exceptionally large filtration area provided by the nests of strainer tubes reduces the frequency of the cleaning cycle and as the V-slots in the tubes easily release the accumulated debris the quantity of water needed for backflushing is very small.
SPX has decades of experience in supply to the power industry and an in-depth understanding of its challenges and requirements. Its Plenty filtration products are proven to be safe, robust and reliable in harsh environments and expert customised engineering enables the most exacting of requirements to be met. Offering high performance, reliable protection of valuable equipment and low maintenance, SPX Plenty strainers are a product of choice for critical power plants.