(if possible), pumps should be brought up to
power slowly, and valves opened slowly. To
avoid damage from both fluid hammer and
surges, a surge chamber should be installed.
Symptoms of fluid hammer and surge’s dam-
aging effects:
• Digital Gauge exhibits large zero offset.
• Digital Gauge pressure display remains
constant regardless of pressure
• Error code is displayed on screen.
FREEZING:
Prohibit freezing of media in pressure port.
Unit should be drained. (Mount in vertical po-
sition to prevent possible overpressure
damage from frozen media.)
3. INSTALLATION:
This procedure requires the use of a 1
1
⁄
16
˝
(27mm) hex wrench for tightening the in-
strument to the process connection. Apply
Teflon tape or a suitable sealing compound
to NPT threads of the gauge. Take using the
wrench, tighten 1 turn beyond hand-tight
or until a leak-proof seal has been
achieved.
Caution:
Tightening the product by
grasping or putting a tool on the plastic
housing can cause permanent damage to
the product.
3
WARNING! READ BEFORE INSTALLATION
1. GENERAL:
A failure resulting in injury or damage may be
caused by excessive overpressure, excessive
vibration or pressure pulsation, excessive in-
strument temperature, corrosion of the pres-
sure containing parts, or other misuse.
Consult Ashcroft Inc. Stratford, Connecticut,
USA before installing if there are any ques-
tions or concerns.
2. OVERPRESSURE:
Pressure spikes in excess of the rated over-
pressure capability of the gauge may cause
irreversible electrical and/or mechanical
damage to the pressure measuring and con-
taining elements. Fluid hammer and surges
can destroy any pressure transducer and
must always be avoided. A pressure snubber
should be installed to eliminate the damaging
hammer effects. Fluid hammer occurs when
a liquid flow is suddenly stopped, as with
quick closing solenoid valves. Surges occur
when flow is suddenly begun, as when a
pump is turned on at full power or a valve is
quickly opened.
PRESSURE SURGES:
Surges are particularly damaging to pressure
gauges if the pipe is originally empty. To avoid
pressure surges, fluid lines should remain full
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Summary of Contents for DG25
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