DESMI PUMPING TECHNOLOGY A/S P a g e | - 31 -Tagholm 19400 Nørresundby - DenmarkPhone.: +45 96 32 81 11Fax : +45 98 17 54 99E-mail: desmi@desmi.comwww.desmi.com10.7.3 Threaded couplingThreaded couplings must always be made by skilled professionalsConnecting a pump with an internal thread to a pipe with a conical thread can causethe pump casing to burst if the coupling is over-tightened.We recommend that you connect pumps with an internal thread to pipes with a cylindricalthread.10.8 Dry runningThe pump should be secured against dry running as otherwise it will result in unnecessary wearor destruction. Dry running results in heat development and potential spark formation at pumpcasing, bearings and shaft sealings.Pump supplied for potentially explosive environments must therefore always be secured againstdry running as otherwise there is a risk of explosion on account of overheating and sparkformation.Pumps for potentially explosive environments must be secured against dry running either bymeans of fitting a Liquiphant™ or other comparable devices with at least the same safety effect.The Liquiphant™ should be fitted to the inlet pipe according to the manufacturer’s installationinstructions.The Liquiphant™ may normally be used for liquids up to 10,000 cSt and a pressure up to 64bar. However, the manufacturer’s technical data shall apply if they deviate from what ismentioned.See the supplier’s technical data!For pumps used for pumping of liquids with a higher viscosity and/or operating under a higherpressure than mentioned – such as pump types HD, PD, CD – another device comparable tothe Liquiphant™ should be used. Dry running may for example be secured in the pipeconstruction, at the inlet on the suction side of the pump so that it is ensured that there isalways liquid in the pump, and at the same time it may be secured that the system’s liquid tankon the suction side does not run dry for liquid.All pump types and pump sizes must always be protected against dry running eitherby means of a Liquiphant™ or other comparable devicesATEX
