PUMP CONSTRUCTION
Little Giant tube pumps consist of a cylidrical aluminum housing
that accepts a flexible tube radially against the inside and an
impeller assembly consisting of ball bearings rotates in the cylinder.
As the impeller rotates, it squeezes tubing which will create a
suction on the intake side and draw fluid through the tubing, creating
a pumping action. Fluid being pumped never touches any pump
parts except for the tubing.
TUBING
Selection of proper tubing or each application is extremely impor-
tant. Tubing selected must be chemically inert to the materials
being pumped. Three types of tubing are most commonly used.
They are: rubber, Tygon R3602 and neoprene. All three types are
sufficiently flexible and can be squeezed shut and then rapidly
regain their shape after the rollers pass over them. Tubing with
the hardness of 60 durometer gives good performance. The wall
thickness for any tubing used should be 1/8". The LG-100 series
accepts 3/16" x 7/16" to 1/4" x 1/2" tubing. The LG-300 series
accepts 3/8" x 5/8" to 1/2" x 3/4" tubing. Do not use tubing with
wall thickness over 1/8".
PUMP DRIVE
Little Giant tube pumps work well at any speed up to 800 RPMs.
The pump is supplied with a 6" pulley. When combined with a
2-1/2" motor pulley and a 1,725 RPM motor, pump speed will be
appoximately 700 RPMs.
NOTE:
Motor, motor pulley and V-belt are not included with the
LG-100 series and LG-300 series Tube Pumps.
Recommended motor for either pump series is a 1/3 HP, 60
hertz, 1,725 RPM NEMA 48 frame motor with rigid cradle base,
sleeve bearings, thermal protection, 40°C rise, 1.35 service factor,
and insulation class A. Suggested motors are Dayton 6K490,
General Electric 5XBH024, or Marathon Q48S17D596. The motor
pulley should be 2-1/2" OD for type A (or 4L) V-belt for 1/2" shaft
(Grainger 3X900 or equivalent). The belt should be a 4L width.
Belt length using Little Giant base should be 30" (Grainger 4L-300
or equivalent).
TUBING INSTALLATION
Remove the pump housing cover by removing the three cover
thumb screws. Position the impeller parallel to the pump’s base.
Place the tubing in one of the grooves in the pump housing and
rotate the impeller while placing the tubing in the position behind
the turning impeller. Seat the tubing fully up against the back of
the housing. Be sure the impeller bearings press the tubing evenly
against the housing and does not overhang the bearings as they
turn. Improper positioning of the tubing will cause wear and tubing
will be cut by the impeller bearings. Silicon lubricant on the tubing
where the impeller bearings rub will increase the tubing life. When
replacing the cover, adjust the tubing clamps until they hold the
tubing tight enough so that it cannot be pulled through the pump
when the cover is installed. For 3/4" O.D. tubing, use the #10-24
x 1/2" screws installed at the factory. For 5/8" O.D. tubing, remove
the clamp screws (2) and install the #10-24 x 5/8" screws which
are supplied with the pump in a seperate plastic bag. If the clamps
are too tight, the flow will be restricted.
OPERATION AND SERVICE
Do not restrict the pump’s output any more than necessary. The
pump can build up high pressures that could exceed the tubing’s
strength.
Some pulsating in the discharge is unavoidable because of the
peristaltic action and can be reduced by putting an expansion
tank in the discharge line. Using 1/8" wall thickness tubing, the
pump is self-priming.
Maintenance must be performed regularly. The roller’s constant
squeezing and releasing the tubing wears the tubing out. Silicon
lubricant on the tubing lengthens tubing life. If possible, install
tubing longer than is required and periodically loosen the cover
plate and slide the tubing through the pump approximately 1' to
allow the roller to wear on new sections of the tubing. Tubing
must be periodically replaced. All pump bearings are sealed and
require no maintenance.
1
LG-100 SERIES
LG-300 SERIES
MODEL
LENGTH
HEIGHT
WIDTH
GALLONS PER MINUTE @ TUBING SIZE
R.P.M.
WEIGHT
3/16 x 7/16 1/4 x 1/2
3/8 x 5/8
1/2 x 3/4
LG-10 0
6"
6 1/2"
4 7/8"
.6
1
—
—
575
4.6
LG-101
15"
9 3/8"
9 5/8"
.6
1
—
—
575
25.2
LG-300
6 1/8"
6 1/2"
5 1/2"
—
—
2.8
4.8
575
6.6
LG-301
15"
9 3/8"
9 5/8"
—
—
2.8
4.8
575
26.12
The above G.P.M. remains almost constant at any pressure from 1-20 P.S.I.
Franklin Electric Co., Inc.
P. O. Box 12010
Oklahoma City, OK 73157-2010
405.947.2511 • Fax: 405.947.8720
www.LittleGiantPump.com
