User's Manual

LTL-400Thrif-T Luber Low-Pressure Orifi ce Lubrication System
SYSTEM DESIGN & COMPONENT SOLUTION
Plumbing —
Lubricant fl ow velocity within this system is relatively low. To
assure accurate proportioning through the various orifi ces in
the system, it’s important that velocity remain low. Signifi cant
pressure drop through long delivery lines may affect the volume
of oil delivered by the orifi ce fi tting at the end of that line. For
general application, 4 mm (5/32 in.) tubing is recommended.
Where applicable this tubing may be:
• 4 mm (5/32 in.) dia. x .64 mm (.025 in.) wall nylon
(where fl exibility is required)
• 4 mm (5/32 in.) dia. x .51 mm (.020 in.) wall steel tubing
• 4 mm (5/32 in.) dia. x .64 mm (.025 in.) wall copper
tubing (where ease of installation is required)
• 3.18 mm (1/8 in.) dia. hose (where movement and
fl exibility are required.
Automatic (Electric Pump) Systems —
The selection of the tubing for the main line may affect the
orifi ce selection in an automatic cyclic system which is in- tended
to operate with a pump pressure between 20 and 150 psi. Main
line pressure drop may affect the orifi ce proportioning if the fl uid
viscosity exceeds 3,000 SUS at operating temperature. Main
line pressure drop (psi) should not exceed 15 percent of system
pressure. Main line pressure drop may be calculated by fi rst
determining the Q value of the line with the following formula:
Q = 53,192,000 xd
4
where: d = inside diameter of the
main line
L L = the length of line
(in inches)
For 5/32-in. tubing with
025-in. wall, the formula is: Q = 560 ÷ length of line
(in feet)
The pressure drop of the line
can be determined
by: P = F x V where: P = line pressure drop
Q F = pump fl ow rate (.40 for
the Thrif-T Luber
Electric Pump)
V = viscosity of fl uid at
operating temperature
Q = the fl ow value of the
tubing (see preceding)
When the main line exceeds 10 feet, or the fl uid viscosity exceeds
5,000 SUS at operating temperature, consult the factory.
Prefi lling the System —
The system and all of its delivery lines must be fi lled with oil
prior to initial operation of the equipment to be lubricated. Also,
the system should be fi lled after a substantial machine shutdown
period. This assures immediate lube supply to the bearings. The
prefi ll volume may be as little as 1.0 cubic inch or as much as 3.0
cubic inches in larger systems.
In Thrif-T Luber Electric Pump supplied
systems...
Prepriming may require several minutes of pump operation for
small systems. Larger systems may require six to eight minutes of
pump operation. The manual run button may be used to override
the normal pump setting.
The system can be considered adequately preprimed when oil
fl ow is observed at the most remote point of the system, or (if
pump has gauge accessory) when gauge pressure reaches the
planned pressure level.
In Thrif-T Luber Manual Pump supplied
systems...
Prefi lling may require several operations of the pump handle. The
system is adequately preprimed when the pump handle recedes
slowly.
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