Watson-Marlow 521VI/RELC, 521I/RELC, 521F/RELC, 521FX/RELC: 0-2 bar IP55 pumps fitted with LoadSure low-pressure element pumpheads 521 close coupled pumps offer IP55 ingress protection for light industrial environments. They offer rugged, industrial pumping, with all the pumphead features of cased drives, but at the lowest whole-life cost.520REL low-pressure LoadSure element pumphead features large swept volume with sprung rollers for high accuracyChemically-resistant polyphenylene sulphide track and rotor, and stainless steel rollers and bearingsLow rotational speeds greatly increase tube life and system reliabilityClutched rotor for rapid, effortless tube loadingRugged, tool-unlockable guard521VI Varmeca close coupled drives bring 10:1 speed control, constant torque output and total reliability to the industrial environment. The drive offers 230V and 400V three-phase power options, plus 110V and 230V single-phase. Control is by a large speed knob and forward/reverse switching.Varmeca integral inverter offering 10:1 control ratio: 63 rpm, 220 rpm and 275 rpm maximum speedsStop/forward/reverse control and analogue or digital remote control. There is a PROFIBUS option521F Fixed speed drives are three-phase poweredThere is a choice of speeds: 60 rpm, 213 rpm and 291 rpmFlow rates from 2.5 ml/min to 4,600 ml/minOther speeds are available on request521FX Duplex fixed speed drives have twin pumpheads allowing two channel pumping.There is a choice of speeds: 55 rpm and 183 rpmFlow rates to 860 ml/min from each channelTwin 520R2C pumpheads for balanced flow in two channels521I Inverter-controlled, variable speed drives include a stand-alone Siemens inverter to control pump speed.Inverter can be mounted beside the pump or remotelyThree speed ranges: 6-60 rpm; 21-213 rpm; 29-291 rpmFlow rates to 4,600ml/min