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Technical product information

Pressure reducer RMG 219 (119a)

rmg regel + messtechnik gmbh

pressure reducer rmg 219 (119a) Application, properties, technical specifications

Application • For industrial and process application • Suitable for gases accor. to DVGW Worksheet G 260 and neutral, non-aggressive gases: Other gases: on enquiry. Characteristics


• Single-stage pressure reducer • Bubble-tight sealing at zero flow • Integrated safety relief valve • Easy operation and monitoring

1. Technical data

Technical data Max. admissible pressure

PS = 50 bar

Max. inlet pressure

pumax up to 50 bar

Set range Optional, depending on measuring unit

Wd = 8 mbar to 8 bar

Valve diameter and KG value

Type of connection

Valve Ø (mm)

KG value (m3/h⋅bar)

2 3.7 5.5 8

4,5 15 35 65

Inlet: • G3/4a (up to pumax 50 bar) • Screw connections accor. to DIN EN ISO 8434-1 (DIN 2353) for external pipe diameters 10 mm, 12 mm and 16 mm Outlet: • G3/4a


Valve body: AL alloy Internal parts: St, Ms, Al, Niro Diaphragm: Perbunan

CE registration according to PED

Temperature range

–15 °C to +60 °C

All mechanical components of this device are without ignition sources. They are not subject to ATEX 95 (94/9/EC). The electrical components used with this device fulfil the ATEX requirements.

pressure reducer rmg 219 (119a) Suitable measuring units and pressure valves for RMG 219 (119a)

Suitable measuring units and pressure valves for RMG 219 (119A)

SUITABLE MEASURING UNITS AND PRESSURE VALVES FOR RMG 219 (119A) Measuring unit – ­description and size Ø (mm)

G 190

V 112

Pressure valves Set range Wd

Wire Ø (mm)


8 to 12 mbar 10 to 40 mbar 30 to 100 mbar 30 to 250 mbar 50 to 500 mbar

2.5 3 4 4.5 6

F1 F2 F3 F4 F5

0.1 to1 bar 0.2 to 1.8 bar 0.3 to 2 bar

6.5 8 9

F6 F7 F8

0.1 to 1 bar 0.2 to 2 bar 0.4 to 4 bar 0.7 to 7 bar 0.8 to 8 bar

4.5 6 6.5 8 9

F4 F5 F6 F7 F8

Description / Ø (mm)

pu max. (bar)

F2 F3.7 F5.5 F8

50 50 50 50

F2 F3.7 F5.5 F8

50 50 50 50


pressure reducer rmg 219 (119a) Load dependence

Load dependence in mbar for measuring units Load dependence in mbar for measuring units Jet Ă˜ (mm) Measuring units

Spring Jet 2

Jet 3.7

Jet 5.5

Jet 8


F1 F2 F3 F4 F5 F6 F7 F8

0.6 mbar 1.4 mbar 4.8 mbar 9.2 mbar 21 mbar 35 mbar 68 mbar 112 mbar

1.1 mbar 2.4 mbar 8.1 mbar 15.6 mbar 35 mbar 60 mbar 115 mbar 190 mbar

1.5 mbar 3.4 mbar 11.5 mbar 22 mbar 50 mbar 84 mbar 163 mbar 267 mbar

2.1 mbar 4.8 mbar 16.3 mbar 31 mbar 70.5 mbar 119 mbar 231 mbar 380 mbar


F4 F5 F6 F7 F8

0.036 bar 0.088 bar 0.13 bar 0.23 bar 0.38 bar

0.062 bar 0.11 bar 0.22 bar 0.4 bar 0.64 bar

0.087 bar 0.16 bar 0.31 bar 0.56 bar 0.9 bar

0.12 bar 0.23 bar 0.44 bar 0.79 bar 1.27 bar


Values are given in mbar or bar and apply to a fully open jet. If the flow rate required (Qreq) at fully open jet is smaller than the max. flow rate (Qmax), the load dependence will fall according to values of the table. Example: Qreq = 50 % of Qmax of the jet. That means load dependence is 50 % of the table value as well.

pressure reducer rmg 219 (119a) Load dependence

Devices with measuring unit V are used whenever the inlet pressure range bpu and flow rate qn are relatively small. Devices with bigger measuring units G are for greater inlet pressure ranges bpu, greater flow rates qn and relatively small setpoint values. The purpose of the table is to determine load dependences.



• smallest inlet pressure pu = 15 bar • highest inlet pressure pu = 30 bar • measuring unit G • regulating jet F 5,5 • setpoint of outlet value pd = 30 mbar Setpoint deviation due to inlet pressure changing from 15 to 30 bar. Calculation of setpoint deviation: Differential pressure pu = 15 bar Correction factor = 0.8 Setpoint deviation of 12 mbar (15 x 0.8 mbar) accor. to the table. The setpoint must be adjusted to the medium inlet pressure! That means the device works as follows: at 15 bar inlet pressure 30 – 6 = 24 mbar at 22.5 bar inlet pressure = 30 mbar at 30 bar inlet pressure 30 + 6 = 36 mbar

Correction values for adjusting the setpoint value Correction values for adjusting the setpoint value Setpoint change (mbar / 1 bar – inlet pressure pu) Measuring units Jet Ø

F2 F3.7 F5.5 F8



0.5 1.5 3.5 7

0.1 0.4 0.8 1.8

pressure reducer rmg 219 (119a) Construction and mode of operation

Construction and mode of operation


The measuring unit consists of the measuring diaphragm of the setpoint spring and the screw for adjusting the setpoint value w. Multiplying the outlet pressure pd by the working surface of the diaphragm reveals the force acting against the force of the setpoint spring. Usually, the two forces will be in balance, thus keeping the working piston and preceding jet in the open position. However, if the outlet pressure pd should decrease under the setpoint value, the force of the setpoint spring will prevail, actuating the lever and thus the final control element. When the control element opens, the gas finds a greater orifice to flow through. With the flow rate increased, the actual value will approach the setpoint value again until both the forces generated by the outlet pressure pd and the setpoint spring are in balance again. (The regulating accuracy is thus determined by the surface of the measuring diaphragm, the diameter of the jet and the lever transmission.) Multiplying the actual inlet pressure pu by the working surface of the piston will reveal the force pushing the jet in the “open“ direction. The purpose of the lever system is to reduce the force acting on the piston in order to diminish the influence of the inlet pressure. An alternative would be to use bigger measuring units that would have the same effect. A bigger measuring unit would generate a bigger force acting on the lever system at the same outlet pressure pd, thanks to the larger diaphragm surface. The effect would be that the influence of the inlet pressure is reduced to a minimum. It is therefore necessary to correct the setpoint value w for a given range of the inlet pressure increase. The table “Correction values for adjusting setpoint values” contains the correction values (inlet pressure influences) for the various measuring units and regulating jets.

setpoint adjuster setpoint spring diaphragm final control element

vent line lever system

pressure reducer rmg 219 (119a) Dimensions Dimensions

Ø 112

Ø 190

G 3/4 a

G 3/4 a





Device with measuring unit G

Device description (example)

Device with measuring unit V

RMG 219 - G3/4a / G3/4a - F3.7 - G - F3 Type Inlet Outlet Valve Ø Measuring unit Spring

For pressure reducer RMG 219 with inlet and outlet connections G3/4a; diameter of valve: 3.7 mm. Measuring unit G with spring F3 for set range Wd from 30 to 100 mbar.

serving the gas industry worldwide

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Germany RMG Regel + Messtechnik GmbH Osterholzstrasse 45 D-34123 Kassel, Germany Phone +49 (0)561 5007-0 Fax +49 (0)561 5007-107

WÄGA Wärme-Gastechnik GmbH Osterholzstrasse 45 D-34123 Kassel, Germany Phone +49 (0)561 5007-0 Fax +49 (0)561 5007-207

RMG Messtechnik GmbH Otto-Hahn-Strasse 5 D-35510 Butzbach, Germany Phone +49 (0)6033 897-0 Fax +49 (0)6033 897-130

RMG Gaselan Regel + Messtechnik GmbH Julius-Pintsch-Ring D-15517 Fürstenwalde, Germany Phone +49 (0)3361 356-60 Fax +49 (0)3361 356-836



Bryan Donkin RMG Gas Controls Ltd. Enterprise Drive, Holmewood Chesterfield S42 5UZ, England Fon +44 (0)12 46 501-501 Fax +44 (0)12 46 501-500

Bryan Donkin RMG Canada Ltd. 50 Clarke Street South, Woodstock Ontario N4S 7Y5, Canada Phone +1 (0)519 53 98 531 Fax +1 (0)519 53 73 339



Gazomet Sp. z o.o. ul. Sarnowska 2 63-900 Rawicz, Poland Phone +48 (0)65 546 24 01 Fax +48 (0)65 546 24 08

Mercury Instruments LLC 3940 Virginia Avenue Cincinnati, Ohio 45227 Phone +1 513 272-1111 Fax +1 513 272-0211

Technical modifications reserved

Last update: 03/2009

Pressure reducer RMG 219