DUNGS MB-VEF 415-425 B01, Gas-air-ratio control

[{"filename":"mb-vef-415-425-b01_datasheet_en_225658.pdf","text":"GasMultiBloc\n Combined regulation and\n safety valve\n Infinitely variable air/gas\n ratio control mode\n\n MB-VEF 415 - 425 B01\n\n 7.28\n\n\n\n\n Flange, line sockets, pulse lines and screw unions are not contained in the scope of supply\n\n\n Technical description The modular system permits individual solu-\n The DUNGS GasMultiBloc MB-VEF…B01 in- tions using valve proving system, min./max.\n tegrates filter, gas-air ratio controls, valves and pressure switch, pressure limiter.\n pressure switches in one compact fitting:\n Application\n - Dirt trap The gas-air ratio control enables the opti-\n MB-VEF 415/420: pre-mount filter mum mixture formation for forced air burn-\n (microfilter) ers and premix burners; this applies to the\n MB-VEF 425: sieve modulating and two-stage variable operat-\n - Solenoid valves up to 360 mbar (36 kPa) ing modes. Suitable for gases of families 1,\n as per DIN EN 161 Class A Group 2 2, 3 and other neutral gaseous media.\n\n\n\n\n Printed in Germany • Edition 04.19 • Nr. 225 658\n - Sensitive adjustment of gas and air pres-\n sure ratio Approvals\n - Servo pressure regulator as per DIN EU type testing certificate as per:\n EN 88-1 Class A Group 2; EN 12067-1 • EU-Gas Appliances Regulation\n - High flow values at low pressure drop • EU-Pressure Equipment Directive\n - Ratio V = pBr / pL 0.75 : 1 ... 3 : 1 Approvals in other important gas consum-\n - Zero point correction N possible ing countries.\n - External pulse lines, pulse flange\n - Interference degree N possible\n - Flange connections with pipe threads as\n per ISO 7/1\n1…8\n\fFunctional description Block diagram MB-VEF\nGas flow\n1. If the valves V1 and V2 are closed,\n chamber a is under input pressure\n up to the double seat of valve V1.\n2. A hole in the filter housing of\n MB-...415/420 connects min. pres-\n sure switch with chamber a. If the\n input pressure applied to the pres-\n sure switch exceeds the incoming\n reference value, it switches through\n to the automatic burner control.\n3. After release by the automatic burner\n control, valves V1 and V2 open.\n The gas flow through chambers\n a, b and c of the MultiBloc is then\n released.\n V1 Main valve 1 a, b, c Pressure chambers in\n V2 Main valve 2 flow direction\nOperating method of valve-regulator\n V3 Control valve 3 pBr Burner pressure\ncombination on valve V1 V4 Control valve 4 pF Firing chamber pressure\nA regulator compensated for residual pamb Ambient pressure\npressure is integrated in valve V1 (pres- M Working diaphragm pL Blower pressure\n D Throttling point\nsure regulating part).\n 1, 2, 3, 4, 5 G 1/8 screw plug\nAnchor V1 is not connected with the V Ratio setting 9 test nipples\nvalve plate unit. When it opens, the N Zero point correction 6, 7, 8 Pulse lines pL, pF, pBr\nanchor pretensions the pressure spring\nand releases the valve plate unit. Pressure taps, gas train diagram\nWhen the valve closes, the anchor acts\ndirectly on the valve plate unit. MB-VEF 415/420\nValves V1 and V2 are released at the\nsame time.\nIn closed position valve V3 blocks the\npressure chamber under working dia-\nphragm M against input pressure Pe in\nchamber a.\n\nThe pressure under working diaphragm\nM is defined by a variable flow cross-\n 2 3 4\nsection D.The comparison diaphragms MB-VEF 425 p p p\n\nfor burner pressure pBr and blower\npressure pL are interconnected via a\nrod. Moving the bearing point sets the\nratio V.\nZero point correction N acts on this rod.\nThe ambient pressure pamb or the firing\nchamber pressure pF must be applied\nto the opposite side of the comparison\ndiaphragms. Firing chamber pressure\nhas a reducing effect on the burner\npressure at a ratio of V > 1.\nChanges2p resulting 3from\n p\n the\n 4\n p\n force\nequilibrium lead to a modification of\nthe flow cross-section D downstream\nof valve V4. Pressure under the work-\ning diaphragm is re-adjusted and the\nvalve plate unit V1 changes the free\ncross-section.\n\nOperating method of valve V2\nThe anchor of valve V2 is connected Valve V4 is activated by valve V2. In Closing function\nwith the valve plate unit.When it opens, closed position, valve V4 blocks the If the supply voltage to the solenoid\nthe anchor pretensions the pressure chamber under the working diaphragm coils is interrupted, the pressure spring\nspring. M from the burner pressure. closes the main valves within < 1 s.\nValve V2 opens completely and without\ndelay.\n\n 2…8\n\f Specifications\n\n Nominal diameters MB-VEF 415 B01, MB-VEF 420 B01 MB-VEF 425 B01\n Flange with pipe threads as per Rp 1, 1 1/4, 1 1/2, 2\t\t\t Rp 2\n ISO 7/1 (DIN 2999) and their combinations\t\t\n\n Max. operating pressure 360 mbar\n Input pressure ranges MB-…VEF S10/12 pe : 5 mbar to 100 mbar\n MB-…VEF S30/32 pe : 100 mbar to 360 mbar\n Guiding range pL : 0.4 to 100 mbar\n Burner pressure range pBr: 0.5 to 100 mbar\n\n Media Gases of families 1, 2, 3 and other neutral gaseous media\n\n Ambient temperature -15 °C to +70 °C (Do not operate MB-VEF below 0 °C in liquid gas systems. Only\n suitable for gaseous liquid gas, liquid hydrocarbons destroy sealing materials)\n\n Dirt trap unit Suitable gas filter must be installed upstream for safety reasons. Filter housing\n with microfilter, for MB-VEF 415/420. For MB-VEF 425, insert gas filter, e.g. type\n GF 520/1. Datasheet pre-mount filter\n\n Pressure switch Types GW…A5, ÜB…A2 / NB…A2 to DIN EN 1854 may be attached.\n For further information, refer to Datasheets 5.02 and 5.07 “Pressure Switches\n for DUNGS Multiple Actuators”\n\n Servo pressure regulator Pressure regulator compensated for residual pressure, leakproof seal when\n switched off by means of valve V1 as per DIN EN 88-1 Class A and EN 12067-\n 1. Gas-air ratio control with adjustable ratio V as well as zero point correction N\n and firing chamber pressure connection.\n\n Ratio setting range V Ratio V = pBr / pL 0.75 : 1 ... 3 : 1; other ratios on request\n\n Zero point correction N Possible\n\n Solenoid valve V1 Valve as per DIN EN 161 Class A Group 2, fast closing, fast opening\n Solenoid valve V2 Valve as per DIN EN 161 Class A Group 2, fast closing, fast opening\n\n Measuring G 1/8 DIN ISO 228, on inlet and outlet flange, on both sides downstream of\n dirt trap, on both sides between valves (pressure switch mounting can partly\n exclude measuring)\n\n Burner pressure monitor pBr Downstream of valve V2, pressure switch mountable laterally to adapter\n Pressure tap on outlet flange\n\n Pulse and connection lines G 1/8 connection as specified to DIN ISO 228 for burner pressure (pBr; GAS), blower\n pressure (pL; AIR), firing chamber pressure (pF ; combustion, atmosphere)\n Pulse and connection lines must be made of steel to PN1, DN4. Conden-\n sate of pulse and connection lines must not enter into fitting. Strictly\n follow the operating and mounting instructions.\n\n Voltage/frequency MB-VEF 415/420 B01: 50 - 60 Hz, 230 V AC, -15% +10 %\n MB-VEF 425 B01: \t\t 50 - 60 Hz, 230 V AC, -15% +10 %\n\n\n Electrical connection Plug connection as per DIN EN 175301-803 for valves and pressure switches\n\n Rating/power consumption see type overview\n Switch-on duration 100 %\n Protection type/interference…