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Gas pressure reducer RMG 214 (D144a)

Technical Description

214.00 Edition 02/2001

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Gas pressure reducer RMG 214 (D144a) Application ● Units for industrial and process technology systems ● Suitable for natural gas and all non-aggressive gas media

Characteristics ● one-stage pressure reducer ● Tight sealing at zero flow ● Design with safety relief valve ● Easy operation and maintenance ● Optionally as backflow-proof version

1. Technical data max. inlet pressure

pemax 350 bar

setpoint range optional dependent on measuring unit

Wh 1 to 75 bar (see table on p.03)

valve diameter and KG value

valve dia. [mm]

20 40 75

6 8 11

connection type

inlet: -R 1" i outlet: -R 1" i

material

housing internal parts diaphragm

temperature range class 2

-20 C to +60 C

function and strength

to DIN 3380

2

KG value [m3/h]

Al alloy St, Ms, Al, Niro NBR

Gas pressure reducer RMG 214 (D144a) 2. Setpoint range

pemax in bar

50

100

150

220

250

300

350

Setpoint range Wh in bar for valve seat dia. in mm

spring

8

6 F1 F2 F3

1 to 5 3 to 20 5 to 45

1 to 4.5 3 to 20 5 to 45

11 2 to 3.5 3 to 20 5 to 45

F1 F2 F3 F4

1 3 5 10

to 4.4 to 20 to 55 to 75

1 3 5 10

to 3.4 to 20 to 55 to 75

3 to 20 5 to 55 10 to 75

F1 F2 F3 F4

1 3 5 10

to 3.5 to 20 to 55 to 75

1 2 5 10

to 2.5 to 20 to 55 to 75

3 to 20 5 to 55 10 to 75

F1 F2 F3 F4

1 to 2.8 2.5 to 20 5 to 55 10 to 75

F1 F2 F3 F4

1.5 to 2.5 2 to 20 5 to 55 10 to 75

F1 F2 F3 F4

1.5 to 1.9 1.5 to 20 5 to 55 10 to 75

F2 F3 F4

3 to 20 5 to 55 10 to 75

3 to 20 5 to 55 10 to 75

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Gas pressure reducer RMG 214 (D144a) 3. Design and operation The gas pressure reducer RMG 214 reduces the variable inlet pressure pe of gas media to the outlet pressure pa, which is adjustable within the setpoint range Wh . The outlet pressure pa is set via spring load onto the measuring diaphragm. The pressure reducer works perfectly from 3 % to 100 % of the maximum flow achievable with the integrated control nozzle. Below 3% the closing pressure range starts with the inevitable increase in pa.

The units seal tight when gas consumption reduces to zero. The outlet side contains a safety relief valve (SBV), which opens when the set response pressure (approx. 30 % above the maximum outlet pressure) is exceeded and can vent any gas leaks.

The housing features a vent connection for the safety relief valve for 9 mm inside diameter. This allows for vented gas to be directed to the outside. The units feature screwed-in inlet and outlet pressure gauges. The pressure reducers are also available with integrated backflow-protection. This only operates when the inlet pressure falls below the outlet pressure. The housing and cover of the standard design are made of brass. The housing can also be fabricated from normal steel. For the functional elements materials resistant against the gas medium will be used.

The pressure reducers are suitable for pressure reduction with gases under high inlet pressure at relatively high flow rates. It is recommended to fit a gas filter in front in order to prevent dirt reaching the internal components.

Where a particularly high flow (outlet flow rate c > approx. 50-60 m/s) is required for the unit, it will be necessary to separate the measuring and flow chambers (intermediate base). This separation prevents undesired dynamic effects resulting from a high-pressure gas stream hitting the measuring and working diaphragm. The separation further leads to improved control accuracy as the outlet pressure required for the measuring chamber will then be read at a location of steady flow within the regulating line.

piston control nozzle guide piece intermediate base measuring diaphragm setpoint spring setpoint adjuster

inlet pressure outlet pressure atmosphere

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Gas pressure reducer RMG 214 (D144a) The measuring unit for the outlet pressure consists of the diaphragm with counter-flow spring loading for setting the outlet pressure. The guide piece forms the connection between the diaphragm and the piston. Changes in outlet pressure compared to the setpoint change the position of the diaphragm and thus the position of the piston in relation to the control nozzle behind it. The sealing face between the piston and the control nozzle is fitted with a plastic seal. Thus the flow path will be sealed off completely, should the gas consumption drop to zero. The spring supports the closing action. The measuring system is balanced, i.e. the position of the piston in relation to the control nozzle is determined by the change of the outlet pressure compared to the preset setpoint value. The intermediate base with measuring connection for attaching a measuring line to the outlet pressure line separates the measuring chamber from the flow chamber. Increases in gas consumption are met by falling outlet pressures.

Load sensitivity is achieved through the effective surface of the working diaphragm, the corresponding setpoint pressure spring, and the opening diameter of the control nozzle. The load sensitivity can be calculated using the table "load sensitivity in bar for setpoint spring" below.

As the gas flow acts on the piston in the closing direction, changes in inlet pressure are transferred in the reverse sense onto the outlet pressure. The setpoint adjustment must be corrected for a given inlet pressure change range (see example below).

The correction values (inlet pressure variations) for the control nozzles to be used can be found in the table below.

Correction values for inlet pressure variations onto the outlet pressure outlet pressure change in bar at 10 bar inlet pressure change for the control nozzles dia. 6 mm

dia. 8 mm

dia. 10 mm

0.12

0.21

0.4

With an inlet pressure rise of 10 bar the outlet pressure reduces by the correction value for the control nozzle. With an inlet pressure drop of 10 bar the outlet presssure rises as per the table values.

Example: Lowest inlet pressure 150 bar, highest inlet pressure 170 bar control nozzle dia. 8 mm, required outlet pressure 50 bar

load sensitivity in bar for setpoint springs nozzle

F1

F2

F3

F4

6 8 11

0.5 0.9 1.3

3.1 5 7.3

12.9 21.2 37

30 48.7 70

The values apply to the fully opened nozzle. Is the required through-flow Qrequ lower than the maximum through-flow Qmax, the load sensitivity shown in the table reduces accordingly.

Example: Qrequ = 50 % of Qmax of the nozzle, then the load sensitivity is also only 50 % of the table values.

Outlet pressure shift by inlet pressure change of 20 bar =

20 x 0,21 = 0,42 bar 10

(value as per table above)

The outlet pressure must be set at middle inlet pressure. The outlet pressure shift must therefore be halved.

The unit then operates as follows: at 150 bar inlet pressure with 50 + 0.21 = 50,21 bar at 160 bar inlet pressure with 50 bar at 170 bar inlet pressure with 50 - 0.21 = 49,79 bar

5

Gas pressure reducer RMG 214 (D144a) 4. Dimensions in mm

appr. 232

appr. 360

appr.152

6

140

/

R1" -

8 -

F3 spring

R1"

valve dia.

-

inlet

RMG 214 type

5. Type description (example)

outlet

Gas pressure reducer RMG 214 (D144a)

For a gas pressure reducer RMG 214 with inlet and outlet connection R1", a valve diameter of 8 mm, and the spring F3 for the setpoint range Wh from 5 to 55 bar.

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We supply products for gas pressure regulation: RMG REGEL + MESSTECHNIK GMBH Osterholzstrasse 45, D-34123 Kassel, Germany Telephone (++49) 561 5007-0 • Fax (++44) 561 5007-107 Gas pressure regulators and safety devices

RMG-GASELAN Regel + Meßtechnik GmbH Julius-Pintsch-Ring 3, D-15517 Fürstenwalde, Germany Telephone (++49) 3361 356-60 • Fax (++49) 3361 356-836 Gas pressure regulators, displacement meters, and complete systems

Bryan Donkin RMG Gas Controls Ltd. Enterprise Drive, Holmewood, Chesterfield S42 5UZ, England Telephone (++44) 1246 501-501 • Fax (++44) 1246 501-500 Gas pressure regulators, safety devices, complete stations

Bryan Donkin RMG Canada Ltd. 50 Clarke Street South, Woodstock, Ontario N4S 7Y5, Canada Telephone (++1) 519 5398531 • Fax (++1) 519 5373339 Domestic pressure regulators and safety devices

other companies of the RMG Group: RMG Messtechnik GmbH Otto-Hahn-Strasse 5, D-35510 Butzbach, Germany Telephone (++49) 6033 897-0 • Fax (++49) 6033 897-130 Turbine meters, vortex meters, correctors, flow computers

Karl Wieser GmbH Anzinger Strasse 14, D-85560 Ebersberg, Germany Telephone (++49) 8092 2097-0 • Fax (++49) 08092 2097-10

works Beindersheim Heinrich-Lanz-Strasse 9, D-67259 Beindersheim, Germany Telephone (++49) 6233 3762-0 • Fax (++49) 6233 3762-40 Data logging, monitor systems, danger alarm systems

WÄGA Wärme-Gastechnik GmbH Osterholzstrasse 45, D-34123 Kassel, Germany Telephone (++49) 561 5007-0 • Fax (++49) 561 5007-207 Design and assembly of gas pressure regulating and metering stations

The RMG Group on the internet: http://www.rmg.de

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Serving the gas industry - WORLDWIDE

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