UFC 4-390-01
23 July 2003
or hydrostatic testing. DOT and ASME flasks should be inspected
and hydrostatically tested in accordance with DOT or ASME
requirements.
B.8.2.1.8 System Pressure Gages. The need for accurate,
reliable, readable pressure gages in unmanned pressure test
facilities cannot be overstated. Sufficient gages should be
located throughout the system so that operators are able to
monitor pressures at all times. Location of gages at the
following points in a system is essential:
a)
Gas manifolds
b)
Volume tanks
c)
H.P. bank manifold
d)
Upstream and downstream of reducing valves
e)
On each compressor stage and at outlet
The prudent designer will locate pressure gages at other
locations throughout the system as operating needs, configuration
or layout may require. Gage operating ranges should be selected
so that system minimum and maximum operating pressure fall
between one-fourth and three-fourths of full scale. Pressure
gages in the system should be accurate to within "1% of full
scale.
Unless specifically exempted by the SCA, each gage should be
provided with a gage isolation valve that is readily accessible
and may be closed to isolate a defective gage from the system.
Valves that act as both isolation valve and calibration
connection port are recommended.
All gages must be securely mounted in a location that permits
easy reading of the dial and access for removal. Gages must be
protected from mechanical vibration, shock and inadvertent
mechanical damage. Care must be taken when mounting gages not to
obstruct or block the operation of the "blow-out" plug.
When a gage is calibrated, a calibration data sheet should be
prepared and retained as part of the certification documentation.
A calibration sticker showing the date of calibration and the
next calibration due date should be affixed to the gage dial or
housing. Calibration should be accomplished only by a qualified
calibration activity. The accuracy of helical-type Bourdon-tube
gages may be verified by performing a comparison check with a
gage that has been calibrated to a national standard. Gage
comparison checks may be performed by qualified personnel within
the command, however, those gages requiring adjustments must be
forwarded to a qualified calibration activity. The dates and
results of comparison checks should be documented and retained.
All gage calibration and comparison should be performed in
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