Low pressure regulator Type NDR 0515 and Type NDR 0516
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ADVANTAGES AND EQUIPMENT
Safety overpressure shut-off valve OPSO
The OPSO - (Over-Pressure Shut Off) is an automatic safety device that protects connected
devices against excessive high pressure. The outlet pressure is monitored constantly. If the
outlet pressure is exceeded, the OPSO responds and the gas feed is interrupted. The visual
display switches from
GREEN
to
RED
.
When it has responded, the OPSO must be opened manually. If the OPSO responds, the
gas feed can be restarted again by following the steps in "Restarting the safety overpressure
shut-off valve OPSO / UPSO". If an OPSO is installed, the pressure regulator is also marked
"OPSO" on the type label.
Under-pressure shut-off device (UPSO) option
The under-pressure shut-off device (UPSO) is a safety device that closes the gas feed if there
is an unusual pressure drop. This can be caused, for example, by the following events:
•
Gas flow > 110% of the nominal flow rate of the double-stage tank regulator, e.g.
because several gas appliances are connected
•
Burst pipe on the outlet side
•
Low pressure on the inlet side (e.g. gas tank is empty)
The gas flow is restored manually when the conditions that triggered the safety device are no
longer present.
If the
UPSO
responds, the gas feed can be restored again by following the steps in
"Restarting the OPSO / UPSO with visual indicator".
The UPSO is marked on the type label of the pressure regulator with “UPSO”.
Pressure relief valve (PRV) option
The pressure relief valve (PRV) is an automatic safety device with limited flow that is installed
in the pressure regulator to protect connected devices against inadmissible high pressures. If
there is inadmissible high pressure at the outlet side, for example due to high temperatures,
the PRV opens and relieves the excess pressure through the breather. When the pressure
falls, the PRV closes again automatically.
A connection to the open air must be created if a pressure regulator with PRV is to be
operated indoors, inside a housing or in any other areas that could be at risk.
"PRV" is marked on the type label of the pressure regulator.
Risk of asphyxiation from gas leaks in enclosed spaces.
High concentrations of gas can cause difficulty in breathing and lead to unconsciousness.
A discharge line must be connected from the breather on the product to outdoors.
GS excess flow valve option
The GS excess flow valve blocks the flow of gas if the volumetric flow rate exceeds a
specified value.
Only a small volume of gas can escape through a small overflow opening.
The GS excess flow valve remains closed until the gas pressure is normal again.
The GS excess flow valve is open when the system is in operation.
If the nominal flow is exceeded by the closing factor, the gas flow is cut off.
This can happen, for example, if opening a screw connection or removing a plug causes the
pressure to drop.
Please refer to the German Technical Rules for LPG (TRF) for information about
dimensioning excess flow valves.
