DESMI PUMPING TECHNOLOGY A/S P a g e | - 48 -Tagholm 19400 Nørresundby - DenmarkPhone.: +45 96 32 81 11Fax : +45 98 17 54 99E-mail: desmi@desmi.comwww.desmi.comAny change to the pump’s operating pressure must be followed by a change to thevalve’s setting - the working pressure must however not exceed the maximumallowable pressure of the pump/valve - see Figure 52.If the valve is not reset, this will mean either that the valve’s safety function fails so that there is a risk of pressure accumulation or that the valve remains open permanently, creating a significant heating up of the pumpand pump liquid – which must not last for a long period of timeThe liquid volume may not circulate through the bypass valve for a long period oftimeCirculation over a long period of time through the bypass valve causes a significantheating up of the pump and pump liquid, and this can create a risk of explosionThe liquid volume may not circulate through the bypass valve for a long period oftime.Recirculation through the bypass valve over a long period of time can causedestruction of the pump.Never set or adjust the bypass valve in operation on account of the danger ofsquirting cold, hot, etching or poisonous liquids under pressureWhenever the valve is set or readjusted, the regulating screw must be repacked withthread tape.14. Pump liquids14.1 Hot liquidsWhen pumping hot liquids at high temperatures, suitable procedures must be drawn up toprevent any danger of injury caused by touching or standing close to the pump.Check daily that the max. allowed temperature is observedThe pump must be shielded when pumping hot liquids that create a surfacetemperature on the pump of more than +80°CA warning sign must be displayed in a clearly visible location!When pumping hot liquids, the pipes must be fitted with compensators to preventtensions in the pump casingThere are various maximum temperatures for ROTAN pumps, depending on the pump type andthe type of elastomer used, see Figure 31 and Figure 32.ATEX
