KST – KROMSCHRÖDER SYSTEMcTECHNOLOGY
5.2.2.4 Gas pressure regulator
A gas pressure regulator shall be incorporated where this is necessary for control of the pressure and the flow rate.
Gas pressure regulators, when fitted, shall comply, with EN 88 or with EN 334 as appropriate.
If the outlet side of the gas pressure regulator and/or the following line section with equipment up to the burner is/are not designed for the maximum supply pressure (inlet upstream pressure to the gas pressure regulator under fault conditions) the following measures shall be applied shutting off the gas supply before an excessively high pressure occurs:
- an over pressure cut off device [1] shall be applied upstream of the gas pressure regulator. This device shall comply with EN 14382;
- the over pressure cut off device shall be designed via an overpressure switch according EN 1854 combined with a safety shut-off valve of EN 161;
- if an over pressure cut-off device is installed a small capacity relief valve shall always be applied downstream of the gas pressure regulator to vent small leakages of the high pressure cut-off.
Pressure adjustment on the gas pressure regulator shall only be possible with a special tool provided for the task.
The following chapters are printed with the permission of the DIN Deutsches Institut für Normung e.V. (German Institute for Standardization). For the implementation of the DIN Standard, the version with the most recent issue date is deemed authoritative. This is available from Beuth Verlag GmbH, Burggrafenstrasse 6, 10787 Berlin, Germany.
Our note on this Standard:
1) We recommend the use of a mechanical safety shut-off valve (SSV), e.g. type JSAV.
The following must be noted if an electrical SSV is used by way of alternative:
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The electrical valve must be installed upstream of the pressure regulator. It does not take the place of the (second) main shut-off valve (5.2.2.3),
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since a valve proving system would have to span different pressure ratings. The test pressure cannot be defined.
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An additional pressure switch must be positioned downstream of the regulator. It issues a signal to the process control system which is required to close the valve safely.
System with mechanical SSV
System with electrical SSV
