Gardner Denver Reavell H5000 Series, Руководство оператора

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ANCILLARY PARTS
PAGE 88
13.7 PRESSURE GAUGES – APP070
PRESSURE GAUGES
GENERAL
The pressure gauge should be installed such as to avoid exposure to heat and vibration and to enable easy
observation of the dial indication.
IMPORTANT
It is common practise to install the pressure gauge without an isolating device, so to facilitate calibration or
replacement the system must be de pressurised before any work is carried out.
The pressure gauge is liquid filled to provide better damping from pulsation’s.
INSTALLATION & COMMISSIONING
The tightening and loosening of torque applied to the connection should be by means of the spanner flats
provided on the stem and should not be by means of grasping the case as this may damage the gauge.
No pressure higher than indicated by the working pressure symbol
W
must be applied to the gauge during
hydrostatic pressure testing of the system. Otherwise the gauge must be isolated or removed during this
operation.
No attempt should be made to remove a pressurised gauge. The pressure system must be totally relieved if
the gauge can not be isolated otherwise.
The remainder of the pressure medium contained in the element may be hazardous or toxic. This should be
considered when handling and storing the removed pressure gauge.
PRESSURE GAUGES IN SERVICE.
Always open isolating devices always gently and never abruptly, as this may generate sudden pressure
surges that may damage the gauge.
The maximum working pressure for which the gauge is suitable, or also the minimum working pressure in
cases of vacuum, is indicated on the dial by corresponding marks
W
. Fluctuating pressure always reduces
the maximum working pressure of the gauge.
Correct zeroing may be inspected by closing the isolating valve and relieving the gauge from pressure. The
pointer must fall within the thickened portion of the zero mark. Unless the gauge temperature is considerably
higher or lower than 20°C, a pointer not returning to zero may indicate serious damage to the gauge.
On-site testing of the pressure gauge is feasible by means of special isolating devices enabling connection
of a test gauge together with a suitable pressure source.