Konten Lembar Data
[{"filename":"NV_en.pdf","text":"NV\n\n Needle valves\n 1/4”… 2”\n\n\n\n\ndelta-elektrogas.com EE189 -0425\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\n\nNV\nNeedle valves\n\n\nContents\n Description ………………………………………….. 2\n Features ……..……………………………..……….. 2\n Functioning and application .………………………. 3\n Technical specifications .………………….……….. 4\n Flow chart (pressure drop) ……........…………….. 5\n Ordering information …..…………………………… 7\n Standards and approvals ………………………….. 7\n\n\n\n\nDescription NV type valves are designed for fine-adjusting of gas flow and air flow in industrial combustion\n processes.\n\n\n\n\nFeatures Valves are made of aluminum, with wide range of threaded connections.\n Suitable for use with air and non-aggressive gases according to EN 437. Special versions for\n critical media are available.\n Valves are operated manually using an Allen key to set the precise fire rate of the burner.\n All components are designed to withstand any mechanical, chemical, thermal condition occurring\n during typical service. Effective impregnation and surface treatments have been used to improve\n mechanical sturdiness, sealing and resistance to corrosion of the components.\n\n\n\n\n WARNING\n This control must be installed in compliance with the rules in force.\n\n\n\n 2-7\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\nFunctioning and\napplication\n\n\n\n\n Fig.1\n\n\n The valve is provided with a taper plunger that can be adjusted sensitively with an Allen wrench,\n turning the screw counterclockwise increases flow, then a locking nut allows to hold the regulation.\n A plastic cap hides the adjustment to avoid tampering with the setting.\n\n\n\n\n NV\n\n\n\n\n Fig. 2\n\n\n Example: in case of combustion process being regulated by combustion air modulation, the\n required lambda value can be set using the fine-adjusting valve NV and an air adjusting cock\n installed as close as possible to the burner.\n\n\n\n WARNING\n NV type valves are not designed for shutting off gas. Use an approved ball valve, plug\n valve or cock to this purpose.\n\n\n\n 3-7\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\nTechnical\nspecifications Tab. 1\n Connections Threaded from Rp1/4 to Rp2\n according to EN 10226-1 or NPT ANSI-ASME B1.20\n Flanged ISO 7005 PN16 from DN40 to DN50\n ANSI-ASA-ASME B16.5 class 150 - 2”\n Ambient temperature -15°C / +60°C\n Media type Air and non-aggressive gases according EN 437\n (special versions for Aggressive Gases and Hydrogen)\n Media temperature +60°C max.\n (special version for air up to +200°C)\n Max. Operating pressure 500 mbar (50 kPa)\n 6 bar (600 kPa)\n Flow rate See diagram\n Materials in contact Aluminium alloy\n with fluid Stainless steel\n Nitrile rubber (NBR)\n Fluoroelastomer (FPM)\n Brass (only 1/4”)\n\n\n\n\n Fig.3\n\n\n Tab. 2\n Connections Overall dimensions Weight Kvs\n [mm] [Kg] [m3/h]\n\n A B C D\n Rp 1/4 25 46 60 90 0,10 0,55\n Rp 3/8 66 76 106 136 0,35 3\n Rp 1/2 66 76 106 136 0,35 5\n Rp 3/4 82 95 124 160 0,57 9\n Rp 1 82 95 124 160 0,57 11\n Rp 1¼ 115 152 159 200 1,50 20\n Rp 1½ 115 152 159 200 1,50 26\n Rp 2 105 156 170 210 1,78 32\n DN 40 165 196 207 247 3,18 32\n DN 50 165 196 207 247 3,18 32\n\n\n 4-7\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\n\n\nFlow chart\n\n\n\n\n Fig.4\n\n\nFormula of conversion\nfrom air to other gases Tab. 3\n\n Gas type Density\n ρ\nVGAS = k∙VAIR [Kg/m³]\n (1) Natural gas 0,80\n (2) LPG 2,00\n ρAIR (3) Air 1,225\nk =√\n ρGAS 15°C, 1013 mbar, dry\n\n\n\n\n 5-7\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\n\n\nWhen the flow read on the diagram is referred to operating pressure instead of standard\nconditions, the pressure drop ∆p read on the diagram must be multiplied for the factor:\n(1+ relative pressure in bar)\n\nExample:\n\nIn the 3/4” needle valve with NG flow of 30 m3/h at standard conditions, there is a pressure drop\n∆p = 10 mbar.\nIf we consider that 30 m3/h is the flow at 200 mbar of inlet pressure, then the pressure drop to be\nconsider is:\n\n∆p = 10x(1+0,2) = 12 mbar\n\n\n\n\nNormally, pressure drop and flow rate for the valves are read from the gas flow diagram.\nHowever, the valves can also be chosen in accordance with the characteristic ”Kvs value” which\nis shown in table 2.\nThe selection of the valve requires the calculation of the Kv under the operating conditions.\n\nConsidering only subcritical pressure drops:\n\n p1\np \n 2\n\nKv can be calculated with the formula:\n\n Vn ρ(t+273)\nKv= √\n 514 Δp⋅p2\n\nwhere\n\nVn = flow rate at standard conditions [m3/h]\nKv = flow factor [m3/h]\nρ = density [Kg/m3]\np1 = absolute inlet pressure [bar]\np2 = absolute outlet pressure [bar]\n∆p = differential pressure p1-p2 [bar]\nt = media temperature [°C]\n\n\nThe valve with the next higher Kvs value should be selected.\n\n\n\n\n 6-7\n\f ELEKTROGAS – Technical Sheet EE189 - 0425\n\n\nOrdering\nInformation\n\n NV 1 -6 N .J\nValve type\n\nSize\n01OTN 1/4”\n0 3/8\"\n1 1/2\"\n2 3/4\"\n3 1\"\n35 1\"¼\n4 1\"½\n6 2\"\n\nMax. Operating pressure\nnone 500 mbar\n-6 6 bar\n\nVariants\nnone Rp threads\nF Flanged connections (only for 1”½ - 2”)\nN NPT threads\n\nSpecial versions\nJ Biogas\nHF Hydrogen\nR Temperature up to 200°C\nZ Anodization of housing and external aluminum parts\nZ1 Epoxy body coating and anodization of inner aluminum parts\n\n\n\n Tab.4\n\nStandards and\napprovals\n NV valves are designed according to EN13611 when applicable.\n\n\n\n Quality Management System certified according to UNI EN ISO 9001.\n\n\n\n\n Elektrogas is a brand name of:\n\n\n Elettromeccanica Delta S.p.A.\n Via Trieste 132\n 31030 Arcade (TV) – ITALY\n\n The information in this document contains general Phone +39 0422 874 068\n descriptions of technical options available and based on www.delta-elektrogas.com\n current specifications. info@delta-elektrogas.com\n The company reserves the right to make changes in\n specifications and models as design improvements are Copyright © 2025\n introduced, without prior notice. All rights reserved\n Visit Elektrogas website for updates and further details.\n\n\n\n\n 7-7"}]
