DUNGS MB-VEF 407-412 B01, Gas-air-ratio control

[{"filename":"mb-vef-407-412-b01_datasheet_en_219543.pdf","text":"GasMultiBloc\n Combined regulating\n and safety valve\n Infinitely variable air/gas\n ratio control mode\n\n MB-VEF 407 - 412 B01\n\n 7.27\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 tions using valve proving system, min./max.\n integrates filter, gas-air ratio controls, valves pressure switch, pressure limiter.\n and pressure switches in one compact\n fitting: Application\n The gas-air ratio control enables the\n - Dirt trap: Fine mesh-sieve optimum mixture formation for forced air\n - Solenoid valves up to 360 mbar (36 kPa) burners and premix burners; this applies\n as per DIN EN 161 Class A Group 2 for modulating and two-stage variable\n - Sensitive adjustment of gas and air pres- operating modes.\n sure ratio Suitable for gases of families 1, 2, 3 and\n - Servo pressure regulator as per DIN EN other neutral gaseous media.\n 88-1 Class A Group 2; EN 12067-1\n - High flow values at low pressure drop Approvals\n - Ratio V = pBr / pL 0.75 : 1 ... 3 : 1 EU type testing certificate as per:\n - Zero point correction N possible • EU-Gas Appliances Regulation\n\n\n\n\n Edition 04.19 • Nr. 219 543\n - External pulse lines • EU-Pressure Equipment Directive\n - Interference degree N Approvals in other important gas consum-\n - Flange connections with pipe threads as ing countries.\n per ISO 7/1\n\n\n1…8\n\fFunctional description\n Block diagram MB-VEF\nGas flow\n1.If the valves V1 and V2 are closed,\n chamber a is under input pressure V1 V2\n up to the double seat of valve V1.\n2.A hole in the filter housing of MB\n 407/412 connects min. pressure\n switch with chamber a. If the input\n pressure applied to the pressure a b c\n 3 4 5\n switch exceeds the incoming refer-\n ence value, it switches through to the\n automatic burner control.\n3.After release by the automatic burner\n M\n control, valves V1 and V2 open. V3 V4\n The gas flow through chambers D\n a, b and c of the MultiBloc is then 9\n released. pBr\nOperating method of valve-regula-\n 8 pF\ntor combination on valve V1 V N pamb\nA regulator compensated for residual Gas-air ratio control part\npressure is integrated in valve V1 (pres- 7\nsure regulating part). pL\nAnchor V1 is not connected with the V1\t\tMain valve 1 pBr\t\tBurner pressure\nvalve plate unit. When it opens, the V2\t\tMain valve 2 pF\t\tFiring chamber pressure\nanchor pretensions the pressure spring V3\t\tControl valve 3 pamb\t\tAmbient pressure\n V4\t\tControl valve 4 pL\t\tBlower pressure\nand releases the valve plate unit.\nWhen the valve closes, the anchor acts M\t\tWorking diaphragm 1, 3, 4, 5\t\tG 1/8 screw plug\ndirectly on the valve plate unit. D\t\tThrottling point 2\t\tTest nipples\nValves V1 and V2 are released at the 6,7,8\t\tPulse lines pL, pF, pBr\n V\t\tRatio setting\nsame time. N\t\tZero point correction\nIn closed position valve V3 blocks the a, b, c\t\tPressure chambers in flow\npressure chamber under working dia- \t\tdirection\nphragm M against input pressure pe in Pressure taps, gas train diagram\nchamber a.\n 2 2\nThe pressure under working diaphragm\nM is defined by a variable flow cross-\nsection D.The comparison diaphragms\nfor burner pressure pBr and blower\npressure pL are interconnected via a 1 5 1\nrod. Moving the bearing point sets the\nratio V.\nZero point correction N acts on this rod.\nThe ambient pressure pamb or the firing 8\nchamber pressure pF must be applied 6 4 3 7 4 3 6\nto the opposite side of the comparison\ndiaphragms. Firing chamber pressure 3\n p\n 4\n p\nhas a reducing effect on the burner 2 e a\n\npressure at a ratio of V > 1.\nChanges resulting from the force 2 5\n min. 5 x DN\nequilibrium lead to a modification of\n 1\nthe flow cross-section D downstream\nof valve V4. Pressure under the work-\ning diaphragm is re-adjusted and the pBr, extern\n PN1, DN 4\nvalve plate unit V1 changes the free 3 4 8\n p p\ncross-section. e a p\n L\n pF\n 6 7\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 When the supply voltage of the main\nthe anchor pretensions the pressure chamber under the working diaphragm valve solenoid coils is interrupted, the\nspring. Valve V2 opens completely and M from the burner pressure. valves are closed within < 1 s by the\nwithout delay. compression springs.\n\n\n 2…8\n\f Specifications\n\n Nominal diameters MB-VEF 407 B01\t\t\t\t MB-VEF 412 B01\n Flange with pipe threads as per Rp 1/2, 3/4\t\t\t\t\t Rp 1, 1 1/4\n ISO 7/1 (DIN 2999) and their combinations\t\t\t and their combinations\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 Fine mesh-sieve.\n Dirt trap unit Replacement only possible by dismounting the fitting.\n\n Types GW…A5, ÜB…A2 / NB…A2 to DIN EN 1854 may be attached.\n Pressure switch For further information, refer to Datasheets 5.02 and 5.07 “Pressure Switches\n for DUNGS Multiple Actuators”\n\n Pressure regulator compensated for residual pressure, leakproof seal when switched\n Servo pressure regulator off by means of valve V1 as per DIN EN 88-1 Class A, Group 2; EN 12067-1\n 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 :…