Westco 16-25, Product Manual, Page: 5 / 49

Functions
The Westco Model 16 casing tong is a hydraulic motor-driven tong capable of running pipe or casing from 2-3/8 to 16
inches in diameter. With a 32 inch (813mm) handle, the tong can produce up to 25,000 lb.ft. (33,895 Nm) in low gear
forward or reverse operation.
An exclusive latch-around (gated), positive-lock jaw system provides sure pipe grip, dynamic balance and safety for
personnel and equipment.
The casing tong incorporates a single or tandem gear-type, fixed-displacement, hydraulic motor to provide drive power
through a gear box and power train. The heart of the unit is a jaw-closing system that forces the jaws together and rotates
them by means of a cam-type rotary gear. The rotary gear is driven by the tow-speed gear train.
In operation, the tong is suspended over the wellbore on a cable. A backup line restrains the tong from moving around
the pipe as torque is applied.
Figure 1-2: Schematic diagram of hydraulic system
Hydraulic Drive System Figure 1-2 is a schematic drawing of the hydraulic drive system. Hydraulic pressure
from a separate power unit is applied through the hose connectors. To prevent cross-
connection of the hoses, the pressure hose is designed to mate with a 1 inch connector
and the return hose with a 1-1/4 inch connector.
The throttle handle controls the throttle valve for the unit. Pushing the handle applies
pressure to drive the motor forward (for make-up operation) and pulling the handle
applies pressure in a reverse direction (for breakout operation). While the handle is in a
neutral position, fluid circulates freely through the valve and back to the return line.
The hydraulic motor and other hydraulic components are mounted on the tong case
top plate.
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Gear Train and Clutch
Closure and rotation of the pipe-gripping jaws is accomplished by a large rotary gear.
Mechanical power is transmitted from the hydraulic motor to turn the rotary gear in
either direction.