Repair sleeves

Over the past years, there have been many attempts to copy the Clock Spring technology in manufacture
of repair sleeves. These attempts continue today, however, these copies are inferior to the original Clock Spring sleeves in all characteristics.

The unique Clock Spring sleeves are used for repair of:

• Pipeline with external damage (corrosive or mechanical)
  with defect depth up to 80% of pipe wall thickness.
• Dents of depth up to 6% of pipe diameter.
• Corrosive defects in girth weld area (two/three sleeves
  are used).

When defect depth is no more than 50% of wall thickness, the repair may be conducted without reducing pressure.

pipe to be repaired with Clock Spring sleeve

This is the state of the art method of restoring the carrying capacity of all diameter pipelines. It is becoming increasingly widespread due to its simplicity and exceptional reliability.

The Clock Spring method is highly cost–effective, due to the fact that repair is carried out without decommissioning the pipeline, does not require additional equipment, and is done directly in the pit.

• Installation takes 30 minutes and the system reaches full strength in 2 hours.
• The sleeve’s unique coil–shaped configuration creates a matrix memory, which allows the Clock Spring to wrap tightly around pipe of virtually any size with practically no additional pressure on the walls.
• Longitudinal flexibility of the sleeve eases repair of the deformed pipe, and transverse rigidity guarantees reliability, quality and longevity.
• During installation of the sleeve, no welding is necessary,
  thus all the dangers of burn through, metal embrittlement,
  and cracking in the weld zone are completely eliminated.
• No environmental risks.

installation of Clock Spring sleeve

The Clock Spring System consist of:

1. a patented, high–strength, unidirectional composite structure,
2. a patenent, fast–curing, high–performance two–part adhesive system,
3. an extremely high compressive strength, proprietary load transferring component.

Once installed, the three elements bond together to form
an extraodinarily strong, durable repair.

Clock Spring sleeve schematics

Sleeve installation consists of four simple stages:

Clock Spring sleeves allow repair of bends, as shown.

applying Clock Spring sleeves
to curved pipe

repaired bend

Clock Spring is the only technology that guarantees a service life of over 50 years after the repair.

This technology has been extensively tested both in laboratories and in the field for:

• Extensive Burst Tests
• Stress Rupture Testing
• Lap Shear Testing
• Compression Testing
• Strain Gauge Analysis
• Cathodic disbondment – Cathodic Shield

pipe segment repaired using Clock Spring sleeves

Besides serving purely repair functions, Clock Spring sleeves halt ductile axial crack propagation and contain cascading ruptures that would occur during bursting.

For low–pressure pipelines, this technology can be used for repair of flaws and other through–wall defects
(Clock Spring Snap Wrap and Clock Spring Leak Stop).

Clock Spring SW (Snap Wrap^TM) — is a high strength corrosion resistant fiberglass composite sleeve, a high performance adhesive and filler material It's designed to repair/reinforce dammaged or corroded section of small diameter pipe operating up to 500 psi with less than 90% thru–wall loss.

The composite split sleeves (8) shaped and sized to wrap around pipe diameters of 3/4" and lager. The individual layers are bonded together and to the pipe surface to fully restore serviceability.

Snap Wrap^TM sleeve

Clock Spring LS (Leak Stop^TM) — is a repair/reinforce technique
for leaking section of pipelines operating up to 350 psi.

Clock Spring LS provides multiple sealing barriers:

1. the defect area is dressed and cleaned,

2. a plug is used to seal the leak and epoxy putty used to provide
a secondary seal,

3. a gasket seal forms the third barrier.

Split–sleeve composite technology is used to compress the sealing barriers and reinforce the leaking area.

Leak Stop^TM sleeve

If the structure and type of defects do not permit the use of Clock Spring sleeves, metal sleeves and patches
are used. With or without filling material, they are either welded or bolted onto the pipeline.