Membrane Level Switch - Kobold

Membrane Level Switchfor Bulk Mediameasuring•monitoring•analyzingNMFPressure: max. 14.5 psiTemperature: max. 390 °FDensity: min. 3.2 lb/ft 3Easy to installSelf-cleaningHandles a wide range of bulkmaterialsMembrane Material: NBR,FKM, or Stainless steel12- 2012KOBOLD companies worldwide:ARGENTINA, AUSTRIA, BELGIUM, BULGARIA, CANADA, CHILE, CHINA, COLUMBIA, CZECH REPUBLIC,EGYPT, FRANCE, GERMANY, GREAT BRITAIN, HUNGARY, INDIA, INDONESIA, ITALY, MALAYSIA, MEXICO,NETHERLANDS, PERU, POLAND, ROMANIA, SINGAPORE, SOUTH KOREA, SPAIN, SWITZER-LAND, TAIWAN,THAILAND, TUNISIA, USA, VIETNAMKOBOLD Instruments, Inc.1801 Parkway View DrivePittsburgh, PA 15205Main Office:+1.412.788.2830+1.412.788.4890info@koboldusa.comwww.koboldusa.com1

Membrane Level Swich Model NMFAreas of ApplicationMembrane level switches allow economic level monitoring of bulkmedia in storage vessels. They may be used to indicate full andempty states and load demand for dusty, powdery, granulated, andgrainy bulk solids. They are suitable for use with bulk materials (19 to144 lb/ft 3 ) and particle sizes up to 30 mm.The devices will operate properly provided the bulk media fl owseasily and does not pile up at a sharp angle. Only such materialsexert suffi cient operating pressure on the detector fi tted in the wallof the silo.Method of OperationThe housing made of cast aluminium or glass reinforced plasticcarries the membrane retained by a screwed on ring.With its own weight, the bulk material presses against the membranewhich is prestressed with a spring through to the support. A plungerfi xed to the membrane transfers the pressure directly to a microswitchwith SPDT contact. If the bulk material subsides, the membrane isrelieved and the contact is switched back.The sensitivity can be adjusted with a spring. The switch can thus beoptimized for the type of fi ll and the installation conditions.Installation with very coarse and/or sharp-edged bulk media:The installation of a guard is recommended for very large grainedand/or sharp-edged materials with high bulk density.A proposal for such a guard is shown in the sketch below. The guardmounted over the level switch protects sensor and membrane fromdamage from dropping bulk material. The curtain (made of rubberor plastic, for instance) protects the membrane from excessive wearby hanging against the membrane as the amount of bulk materialincreases. Make sure that the switch is not in the path of the infl owing material, as otherwise the switch and membrane could bedestroyed very quickly.For use with bulk goodsfor example:AlumBauxiteCeramicsDolomitePeas, peanutsFish mealGravelOats, hazelnutsInsulating materialsCoffee beansLong grain riceCorn, almondsNutsFruitPearliteQuartz sandRiceSand, slagClayVarious granulatesWheatMiscellaneous grainSugarTechnical DetailsInstallation position: VerticalMaintenance:NoneCable entry fi tting: M20 x 1.5Contact loading capacity: 4 A at 250 V AC fl oating SPDT contactWiring DiagramPType codesModel:Membrane material:N = NBRV = FKME = Stainless steelNMF - E N ENC NO C2 1Retaining ring material:N = Galvanized steelE = Stainless steelA = Cast aluminium2 www.koboldusa.comNo responsibility taken for errors;subject to change without prior notice.12- 2012

Membrane Level Switch Model NMFModel NMF-E... most economicModel NMF-F... for greater wall thicknessesM20x1,5M20x1,5Ø 128Ø 124Ø 128Ø 12477142614261543,5154204938Materials:Membrane - NBR or FKMretaining ring - galvanized steelor stainless steel 1.4324housing - glass reinforced plastic GRPWeight:480 gSensitivity:Adjustable between 60 g and 200 gProtection:IP 40 screwed fi tting bottomIP 53 screwed fi tting topContact loading: max. 4 A at 250 V ACTemperature range: -4... 140 °FPressure:Vented, max. 14.5 psiCable entry: M20 x 1.5 fi ttingMounting:VerticalMaterials:Membrane - NBR or FKMretaining ring - galvanized steelor stainless steel 1.4324housing - glass reinforced plastic GRPWeight:530 gSensitivity:Adjustable between 60 g and 200 gProtection:IP 40 screwed fi tting bottomIP 53 screwed fi tting topContact loading: max. 4 A at 250 V ACTemperature range: -4... 140 °FPressure: Vented, max. 14.5Cable entry: M20 x 1.5 fi ttingMounting:VerticalOrder Details (Example: NMF-ENN)Membrane Retaining ring Order NumberOrder Details (Example: NMF-FNN)Membrane Retaining ring Order NumberNBRGalvanized steelSt. steel 1.4324NMF-ENNNMF-ENENBRGalvanized steelSt. steel 1.4324NMF-FNNNMF-FNEFKMGalvanized steelSt. steel 1.4324NMF-EVNNMF-EVEFKMGalvanized steelSt. steel 1.4324NMF-FVNNMF-FVE12 - 2012No responsibility taken for errors;subject to change without prior notice.www.koboldusa.com3

Membrane Level Switch Model NMFModel NMF-D... with double-membraneModel NMF-B... for higher temperatures5 x 72M20x1,5Ø 187154Ø 128Ø 12471421543.5254978020021441482M20x1,5Materials:Membrane - NBR or FKMretaining ring - galvanized steel orstainless steel 1.4324housing - glass reinforced plastic GRPWeight:750 gSensitivity:Adjustable between 60 g and 200 gProtection: IP 65Contact loading: max. 4 A at 250 V ACTemperature range: -4... 158 °FPressure:Vented, max. 14.5 psiCable entry: M20 x 1.5 fi ttingMounting:VerticalOrder Details (Example: NMF-DNN)Membrane Retaining ring Order NumberNBRFKMGalvanized steelSt. steel 1.4324Galvanized steelSt. steel 1.4324NMF-DNNNMF-DNENMF-DVNNMF-DVEMaterials:Membrane - NBR, FKM or stainless steel1.4301retaining ring - cast aluminiumhousing - cast aluminiumWeight:1700 gSensitivity:Adjustable between 100 g and 200 g(NMF-BNA, NMF-BVA)adjustable between 200 g and 500 g(NMF-BEA)Protection:IP 40 screwed fi tting topIP 53 screwed fi tting bottomContact loading: max. 4 A at 250 V ACTemperature range: Membrane NBR -4... 175 °FFKM -4... 300 °FSt. steel -4... 390 °FPressure:Vented, max. 14.5 psiCable entry: M20 x 1.5 fi ttingMounting:VerticalOrder Details (Example: NMF-BNA)Membrane Retaining ring Order NumberNBR Cast aluminium NMF-BNAFKM Cast aluminium NMF-BVAStainless Steel Cast aluminium NMF-BEA4 www.koboldusa.comNo responsibility taken for errors;subject to change without prior notice.12- 2012