Sub-Surface Springs
Multi sub-surface or ‘down hole’ springs
are used to absorb the impact of a falling plunger,
preventing damage to the seating device.
The use of a spring is the only way to ensure that the
down hole equipment fishing head profiles will be maintained
at their original specifications. (Note: Normal wire
line methods can only be used to retrieve this equipment
provided the fishing heads are not damaged.)
The sub-surface springs are made in a modular form to
allow for changes of the bottom assemblies at the end
of the tubing. The modular spring assembly is retrievable
and supported by a sliding sleeve in the spring to protect
it from damage during removal.
Free Standing Spring
The Free Standing Spring includes a NO GO, or bottom
that is larger in diameter than the seating nipple yet
smaller than the ID of the tubing. This allows easy
entry into the tubing, yet allows it to stop on the
seating nipple. The bottom can also be used for standing
valves and either collar or tubing stops.
Latch Down Assembly
The Latch Down Assembly for the bottom of the springs
is a collet device that contains a latch to expand over
the fishing head of the device below it and compress
around it. (Note: the tops of all springs contain the
fishing head to make them retrievable.)
Cup Seat Standing Valve (CSSV)
The CSSV is available for installation in the seating
nipple. This bottom assembly requires a wire line to
seat the device into the nipple. The unit also contains
a series of cups that are oversized to compress in the
seating nipple and allow flow to pass through the inside
of the spring. Finally, the seat ensures that the spring
will always remain at the seating nipple.
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A. Modular Spring
The Modular Spring consists of a Base Unit to which
various options are threaded onto.
B. Base Unit shown with Latch
Down Option
C.
Latch Down Option
D. Cup Seat or Cup Seat Standing
Valve
E. Free Standing Option for
Modular Spring
F. Economy Free Standing Spring
The Economy Free Standing spring is used where a seating
device exists. This unit sits on a seating nipple.
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