QUALITY WELD PAD GAUGES
SERIES QRW & QTW
The Quality Series QRW-20 and QTW-20 are designed so that they can be welded directly on to a pressure vessel. Weld pad gauges are used where regular gauge and valve construction is impractical, due to space constraints, solid matter in the suspension and/or thermal stresses on the gauge glass from the associated piping. Included are applications involving high vibration, highly viscous liquids or liquids with considerable amounts of solids.
Quality Weld Pad Gauges are available in both reflex and transparent versions. These gauges are designed to take pressure within the gauge itself. These gauges are not designed to replace the tank strength lost due to slotting the pressure vessel. It is therefore impossible to give a pressure rating to the weld pad gauge.
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Standard Welding Pad Gauges Design and Installation:Standard Quality weld pad gauges follow other Quality flat glass gauges in general design and materials, except for the method of attaching to the tank or vessel. The chamber of the welding pad gauge 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 gauge. 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 gauge 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. 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 gauges will withstand a loading due to the pressure within the gauge itself, but they are not designed to replace the tank strength lost with tank wall is cut. The gauge 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 gauges. 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: Quality weld pad gauges are engineered and built to Quality’s highest 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 gauges may be furnished with a cold rolled steel space or to replace glass and gaskets. Isolable Welding Pad Gauges Quality Isolable Welding Pad gauges, with control valves, follow the general design of standard Quality welding pad gauges but offer the additional advantages of integral valves. Gaskets and glass can be replaced without lowering the level of liquid below the gauge inlet or relieving pressure from the vessel because the gauge can be isolated from the vessel by the valves. Isolable gauges are installed by matching valve inlets with holes drilled in the vessel and the installer making a 100 percent fillet weld between the vessel wall and valve inlets. The gauge chamber is then tack welded to the vessel.
Series QRW & QTW Gauge and Support Files |
