MAJOR BENEFITS OF USING HydroSwage®
Tube Expansion Issues and Methods White Paper by Mark Bloodworth
THE INTENSIFIER
HydroSwage® systems utilize an intensifier to achieve swage pressure.This method has strong advantages over systems that depend on a single pump to generate the high pressure needed for tube expansion.
• The dampening effect of the intensifier results in smooth, uniformpressure curves for each
expansion cycle.
• Our intensifier contain a valve that senses when the intensified pressure reaches
approximately 95% of the swage pressure setting, at which point the swage timer is
triggered insuring that the pre-set expansion pressure is maintained throughout each
timed swage cycle.
• The intensifier acts as a valve to hold and release the expansion pressuremaking high
pressure cycling more reliable.
• The systempump is not required to supply expansion pressure resulting in longer life to
pressure seals.
• The portability of the intensifier, along with the 20 ft umbilical, aids with expanding in
limited access conditions such as boilers or mud drums.
ACCURACY
The degree of expansion is directly proportional to the pre-set hydraulic pressure.
REPEATABILITY
Each tube is expanded by the same pressure which is held to within an approximate 2% tolerance of ±1000 psi {69 bars}.
QUALITY CONTROL
Expansion history can be stored for download to an Excel spreadsheet. Analog connections are also available for strip chart recorders.
SAFETY
No adverse torque reaction on the operator. Swaging pressure is confined within the tube and tube-sheet. Automatic shutoff if tubemandrel seal is lost
EASE OF OPERATION
Go/No-Go lights alert operator as to the swaged condition of each tube. Since success is determined by pressure, not feel, training time is minimized to a great degree compared to mechanical methods.
FAST
Even the thickest tube sheets are swaged in one step in just seconds. As the tool does all the work, no additional operator is needed to pin tubes to prevent its movement.
VERSATILE
One basic system handles all sizes. Interchangeablemandrels accommodate any tube diameter (1/4" to 2”) and gauge, and any tube-sheet thickness.
ENDS CHASING LEAKS
Even in partial re-tubing operations. the accuracy of the HydroSwage® process minimizes disturbing the seal of adjacent tubes.
NO TUBEWALL REDUCTION
Wall thickness or tube length does not change after contact is made with tube-sheet. Therefore, the seating of the tube is not disturbed as swage pressure is increased nor are theremetallurgical changes.
STRESS CORROSION
Stress corrosion, work hardening and other metallurgical changes areminimized, prolonging tube service life.
REDUCED CREVICE
Reduces crevice corrosion due to accurate control of tube to tube-sheet crevice.
ACCOMODATES DISTORTED HOLES
This is no problemwith theHydroSwage process (within allowable tolerances). Uniformhydraulic pressure swages the tube to each hole's configuration.
FULL PRODUCT LINE
In a shop, in the field, aboard a ship, complete or partial re-tubing, new fabrication, tube setting prior to welding or sleeving, there is a HydroSwage' System for every application.