Kenco Engineering Flat Glass Level Gauge - Manual (Page 2)

Page 2
GAUGE CONSTRUCTION
BEFORE YOU INSTALL THE GAUGE
Consider the following:
• To avoid imposing piping strains on the gauge chamber, connect and mount the gauge so that it does not support
the piping.
• Differential thermal expansions between the vessel and gauge can impose severe mechanical loads on the
gauge, especially if the vessel contains hot or cryogenic liquids. To prevent these, install an expansion loop
between the gauge and vessel, or use a reasonably long run of piping.
•
Support brackets should be considered for gauges over four feet in length or over 100 pounds in weight,
especially when the gauge is exposed to vibration. These support brackets will prevent overloading the
connecting valves and piping and prevent damage to the gauge from excessive vibration.
•
Always provide shutoff valves between the gauge and vessel. Kenco automatic ball check valves are
recommended to provide protection against physical injury and loss of product if glass breakage should occur.
These valves also provide a means to isolate the gauge for maintenance.
•
Bolt torque is vital to the proper operation of a flat glass gauge. Because gaskets compress over time, bolt torque
should be checked before the gauge is installed (see MAINTENANCE). Bolt torque should also be checked after
the first few hours of operation.
OPERATION
Always warm up the gauge slowly when it is used with a vessel containing a hot fluid. Slowly open the shutoff valves
carefully, and wait until the gauge is fully warmed up before completely opening the valves. Kenco Gauges use tempered
glass, designed to withstand thermal shock. However, additional loads that you cannot measure are imposed on the
glass during installation. Resistance to thermal shock is reduced accordingly. This procedure also applies to cold fluids.
During system shutdown, it is best to leave the shutoff valves open so that as the gauge cools it depressurizes along with
the rest of the system. Keeping valves closed during shutdown can trap high pressure liquid in the gauge. For high
pressure / temperature applications a viewing system of mirrors should be used to protect personnel from physical injury
in the event of glass breakage.
Gauges should be isolated periodically and bolt torque checked to prevent leaks. This is especially important on gauges
used in intermittent operation, or varying service conditions. When putting a gauge into service always check for leaks
and be certain the shutoff valves are fully open with all vents and drains closed before leaving the site.
Glass
Cover
Chamber
Reflex Gauge (Model KMR & KHR)
Gasket
Cushion
Transparent Gauge (Model KMT & KHT)
Chamber
Gasket Cushion
Cover
Glass
Cover
Glass
CAUTION – Gauges should always be isolated from the process system by closing the upper and lower
isolation valves, and draining the gauge to relieve pressure before doing any torque or
maintenance checks.
CAUTION – Rapid opening of connecting valves can cause glass breakage and / or possible injury to
personnel. Gauges should be brought into service slowly.