Jerguson
Welding Pad Gages are used where conventional gage and valve
construction is impractical because of (1) solid matter in
suspension, (2) under conditions where the thermal error caused
by piping to a gage glass cannot be tolerated, or (3) where
space requirements suggest their
use. Included are applications involving high vibration,
highly viscous liquids or liquids with considerable amounts
of solids, Jerguson offers end users a flat or radius
weld pad gage. Because there is no nipples through which the
process liquid enters the gage, clogging potential is eliminated.
Jerguson
Welding Pad Gages are made in both Reflex and Transparent
types ... in most Jerguson
standard sizes. Reflex gages are used where liquid level
reading only is required. Transparent gages are usually
used where installation is made on each side of the vessel
to give see-through visibility. See
Picture
Standard
Welding Pad Gages
Design
and Installation: Standard Jerguson welding pad gages follow
other Jerguson flat glass gages in general design and materials,
except for the method of attaching to the tank or vessel.
The chamber of the welding pad gage consists of a bar stock pad, which is welded to the tank after cutting a slot in the
tank wall equal in dimension to the vision slot of the gage.
Alternately, for maximum vessel strength without further reinforcement,
two holes may be drilled in the tank wall with diameters equal
to the width of the vision slot of the gage located at the
top and the bottom of the visible range. For best
results the tank wall behind a reflex gauge should provide
a dark background. The holes, in lieu of of the slot method,
can be used with a transparent type when there's sufficient
visual contrast between the tank wall in the liquid to permit
liquid level interface observation. See
Picture
Pressure
loads:
Where
it is necessary to slot the tank because of the nature of
the liquid or there is need to observe the color or interface
of the liquid, the following facts must be considered:
Standard and welding pad gages will
withstand a loading due to the pressure within the gage itself,
but they are not designed to replace the tank strength lost
with tank wall is cut. The gage manufacturer has no control
over the loading in which the pressure vessel will impose
on the pad. It is therefore impossible to rate welding pad
gages. The tank fabricator must provide suitable tank wall
reinforcement to prevent the pad from being distorted during
welding or while under hot operating condition.
Materials
and construction:
Jerguson
welding pad gages are engineered and build to Jerguson's high
standards, using materials found by test to be the best for
the particular application. The welding pad than in may be
made of any material desired to withstand corrosive or other
conditions.
To prevent distortion and during welding,
welding pad gages may be furnished with a cold rolled steel
space or to replace glass and gaskets.
Isolable
Welding Pad Gages
Jerguson
Isolable Welding Pad gages with control valves follow
the general design of standard Jerguson welding pad gages
but offer the additional advantages of integral valves. Larger
Image
Because the gauge can
be isolated from the vessel by the valves, gaskets or glass
can be replaced without lowering the level of liquid below
the gage inlet or relieving pressure from the vessel.
Isolable gages are installed
by matching valve inlets with holes drilled in the vessel
in making a 100 percent for fillet Weld between the vessel
wall and valve inlets. The gauge chamber is tack welded to
the vessel.