Nessie® Pressure Relief Valve Type VRH 30 VRH 60 and ... - Danfoss

Data sheet Nessie® Pressure Relief Valve type VRH 30, VRH 60 and VRH 120Technical data(continued)Max. flow: 120 l/minPressure setting range: 25 to 80 bar (I), alt. 80 to 140 bar (II)P/QcharacteristicMountingThe valve is mounted in-line and fixed by meansof the system’s piping or fastened (only VRH 120)by means of the two ∅8.5 mm holes in the valve.It is important that valve is bleed to avoid noiseand therefore must the valve be mounted in thecorrect position please see drawing.xxxStarting upTo insure stable working conditions for the valveis it very important to bleed the valve duringstarting up.Noise levelSince the valve typically is mounted inline or ona frame, the noise level can only be determinedfor the complete system. It is therefore veryimportant that the valve is mounted correctly ona frame to minimize vibrations and noise.The noise level is influenced by:• Mounting position of the valve is important toinsure a good bleeding of the valve.• Sufficient Bleeding of the valve.• High pressure generates more noise than lowpressure.• Rigid mounting of the valve generates morenoise than flexible mounting.• Pipe mounting direct to the valve increasesthe noise level compared to a flexible hoseconnection.Corrosion and antifreeze protectionIf the valve is exposed to temperatures belowfreezing, it must be protected against freezing.Danfoss recommends DOWCAL N or Zitrec FCantifreezes both being biologically degradableMono Propylene Glycol (MPG)DOWCAL N is produced by DOW.Zitrec FC is produced by Total / Chevron Texaco.Producers of DOWCAL N and Zitrec FC recommenda mixture ratio of min. 30 % DOWCALN / Zitrec FC to prevent biofilm occurrence in thesystem due to DOWCAL N and Zitrec FC beingbiologically de-gradable.DKCFN.PD.040.A6.02 521B0841 3

Data sheet Nessie® Pressure Relief Valve type VRH 30, VRH 60 and VRH 120Code numbersValve size Comments Code no.VRH 30 Pressure range 25 to 140 bar 180G0030VRH 30 Pressure range 10 to 40 bar 180G0029VRH 30 Pressure range 45 to 210 bar 180G0031VRH 60 Pressure range 10 to 40 bar 180G0001VRH 60 Pressure range 25 to 80 bar 180G0002VRH 60 Pressure range 80 to 140 bar 180G0003VRH 120 Pressure range 25 to 80 bar 180G0020VRH 120 Pressure range 80 to 140 bar 180G0021Dimensions4 DKCFN.PD.040.A6.02 521B0841 Produced by Danfoss Industri Service - Advertising 06.05 LN/Bi.E