Metering and Regulating Station (MRS) whose function is to reduce and regulate the pressure 4 bar of gas supplied from the PE network into the Downstream network as per customer required pressure. MRS used in Industrial/commercial customer . The principal components of a typical MRS are described as follows:
The MRS have available in Single
Stream / Twin stream.
Pressure relief valves : A pressure relief valve limits pressure buildup (i.e, prevents over pressure) at its location in a pressure system. The relief valve opens to prevent a rise of inlet pressure in excess of a specified value. The pressure at which the relief valve begins to open pressure is the relief pressure setting. Pressure relief valves can be direct-operated or pilot- operated.
Filtration: The filtration
of incoming gas is through the filter of a rating adequate for the
types of equipment installed downstream such as pressure regulators,
relief valves, slams etc.
SlamShut-off: Upstream
of the pressure regulator is fitted the Over pressure shut off
(OPSO) valves with the aim of shutting of the Gas flow in the event the
outlet pressure exceeds the set values. OPSO protects the facilities &
equipment downstream of the MRS. MRS is also fitted with Under pressure slam
shut off (UPSO) valves to protect the system in case the pressure drops
to extremely low values (lower than the predefined values i.e. outside the
safe operating envelope)
Pressure
Regulating:
Two pressure regulators are installed in series forming the “Monitor
& Active” configuration with the one taking over the other in case of
malfunction. This system ensures uninterrupted supply of Gas by automatic
switching between the two regulators in the event of the “Active”
suffering a malfunction. The models & ratings of both the regulators are
the same with only a required variation in their pressure settings.
1.
Direct-operated (Self- operated)
2.
Pilot-operated
Creep Relief valve : A creep Relief
Valve is installed Downstream of the regulator for relieving of excess
pressure build ups caused by the such things as the regulator valves not fully
sealing at lockup, sudden drop of consumption or any other fluctuations
causing an upsurge in pressure.
Gas Metering System : Gas metering is very important for transmission and
distribution system and metering station. Through out gas measurement utilizes two basic principles
to measure gas volumes, positive displacement meter and inferential
meters. Positive displacement meters comprise the large majority of
measurement devices in use while inferential meters are used primarily for
large volume measurement.
