Babbitt Liquid Level Gauge - Manual (Page 2)

Detailed Description
The LG Series Level Gage consists of a glass (or polycarbonate) indicator and float chamber,
which is mounted directly to the process vessel. Standard gages are normally flanged or coupled
to the process vessel, but a variety of mounting styles are available to suit most any vessel or
piping requirements. (See Table 1 of the brochure for more details.)
Gages are manufactured to meet the exact specifications of the process such as operating
pressure, temperature, specific gravity, etc. Standard materials are stainless steel, however most
any non-magnetic material may be used including PVC, Kynar, Hastelloy, Monel, Alloy 20, and
many others. A magnetized float is contained inside the chamber, which is designed to meet the
requirements of the process conditions. (For this reason, floats are not interchangeable unless
process conditions are identical.) The float moves freely inside the gage chamber as level rises
and falls. Under normal conditions, the float should be about 70% submerged in the process fluid,
but it is important to note that the position of the float in the fluid will vary with different process
conditions.
STANDARD INDICATION
The scale assembly used for indicating level consists of the clear indicator tube with the red
magnetic follower or “bird” and a graduated scale marked with feet and inches (special scales are
available, ie: metric, gallons, 0-100%, etc.) The scale is mounted parallel and immediately next to
the indicator tube. The tube is hermetically sealed to prevent moisture and dirt accumulation. A
rubber “bumper” is sealed inside the bottom of the tube to cushion the impact of the “bird” against
the glass. The bright red bird provides maximum visibility (even at night), however light kits for
illuminating gages are available. A black reference line around the bird allows the operator to
match the graduated scale with the actual level of the process fluid. Positive zero indication is
provided by a nameplate at the lower end of the scale. If the bird is de-coupled from the float, the
bird will fall down behind this nameplate and will not be visible. Thus, when the vessel is empty, the
level gage will read zero and the bird is still visible float. To prevent the float from losing magnetic
coupling with the bird, a spring or stop plate is mounted into the top and bottom of the gage
chamber. This cushions the impact of the float against the chamber when the process vessel is
completely full or empty.
FLIPPER/ROLLER INDICATION (OPTIONAL)
Babbitt offers a flipper/roller style indicator as an option to the standard tube/follower indicator.
“Flippers” are industrial grade indicators, which consist of a series of metal flags, silver on one side
and red on the other. As the magnetic float moves up and down with the level, each flag will rotate
180° to show the other color.
Babbitt flippers are housed in a rugged, hermetically sealed
aluminum housing with a recessed glass window. Each flag rotates on a ceramic and stainless
steel bearing surface, which eliminates “sticking” or hanging up. Flipper assemblies are built to the
length of the level gage in one continuous piece up to 20 feet with no joints or blind spots.