Model PCU-1 Upstrain Unloader is
designed to equalize tubing and annulus pressures above a PC-1 Retrievable
Cementer Packer or other makes of upstrain actuated tools that are compatible
in operation with that of the Unloader.
The Unloader is made up directly
above the PC-1 Cementer Packer and is usually run in the hole in the open
position to allow fluid bypass through PC-1 and into the annulus. Torque is
transmitted through the unloader to the PC-1 by a key located in a key-slot of
the unloader body. Applying upstrain to set the PC-1 will close the Unloader
and setting down weight will open it.