Torsion Spring-Balance Units
788 and 789 Series
Considered the “workhorse” of the industry,
the OPW Engineered Systems 788 and 789 Series Torsion Spring-Balance Units
are designed for precise, automatic control. These robust units are available
in four sizes, depending on the load to be lifted. Each unit consists of
a torsion spring made from high tensile alloy steel with excellent fatigue-resistant
properties. The spring winds tight as the arm is lowered, providing a counter
torque, which balances the arm. The units are available in right-hand or
left-hand versions. The turning radius range is a minimum of 15" on
a 2" arm; and a maximum of 25" on a 6" arm.
Key Design Features
- Torsion springs constructed of specialty treated, high
tension alloy steel
- Each assembly is fully adjustable within its operating
range
- Major parts are cast in high strength ductile iron:
Includes spring housing and other structural components
- Oil-impregnated bronze bearing carries spring load:
Eliminates ferrous-to-ferrous contact, minimizes wear, ensures smooth operation
- Lifting lever pivots at each end on stainless steel
pins: Prevents corrosion build up and allows arm to move freely
- Special adjustment prevents excessive downward travel
of loading arm
- Seven separate adjustment positions limit upward travel
of loading arm: Operator sets at desired position to prevent arm from hitting
overhead obstructions
- Protective, unbreakable plastic cover keeps dirt and
foreign objects from main spring: Prevents tampering and allows for ease
of inspection/adjustment
- Lockdown unit, (788-L and 788-LLH) secures arm in down
position during loading: This optional unit prevents jetting of liquid
when drop tube is lifted from tank. Locks in any of three positions between
horizontal and 15-degree below horizontal
788 Torsion Spring-Balance Unit
The 788 Torsion Spring-Balance Unit is designed for lighter
lifting applications such as drum filling. This compact, yet strong unit
is ideal for smaller diameter pipe and can be used to support hoses, especially
lightweight vapor type. While the 788 is designed for lighter duty, it is
still manufactured of the same high quality, long-lasting components as the
789. It has the treated, high tension alloy steel spring, bronze bearings
and ductile iron housing. Built to handle a wide range of light duty lifting.
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OPW 788
Torsion Spring-Balance Unit |
OPW 789
Torsion Spring-Balance Unit
(Cover Removed) |
789 Torsion Spring-Balance Unit
The 789 is available in a model “A”, “B”,
and “C” depending on the lift and balance requirements. Designed
for precise automatic control, the 789 has seven separate adjustment positions.
The lockdown unit secures the arm in the down position in three positions
between horizontal and 15 degrees below horizontal.
