Clock Spring - World Leader In Pipeline Repair Solutions

Clock Spring specifications show its design to repair/reinforce damaged or corroded sections of pipe with up to 80% wall loss. Standard Clock Spring contains e-glass continuous strand fibre all aligned in hoop direction and held within a polyester resin matrix. 20,000 hour tests completed (2.3 years duration) which are more representative of long term behaviour than the 1000 hour (42 days tests) required by ISO and ASME. In-service monitoring of repairs, subsequent removal and testing for durations up to 7 years completed and reported.20 ksi (138 MPa) long-term allowable stress derived for 50 year life.

The following report is a pictorial and text account of procedures and operational techniques employed for the export riser repairs. The report is not meant as a technical report but serves as a QA/QC document for the installation of the Clock Spring system.

The defect is external corrosion with wall loss of 40%. Tees are located both before and after the defect. A 3” pipe hangs above the repair section with a tight clearance of only 3 inches.

Extensive external corrosion up to 82% wall loss covering circumferential area, especially at the mean sea level (splash zone).
Offshore Riser Repair with Clock Spring reinforcement sleeve with marine type chemicals utilised. These chemicals have been tested for sub-sea application and will cure even when submerged. The total length of riser being repaired is 5.2 meters. Installation was completed within 9 hours, spanning 1 ½ days. The splash zone section of the riser was repaired within one hour as the crew only had a one hour window at low tide.

Field report from West Malaysia of Clock Spring corrosion repair completed in area of tight clearance. The piping located at cellar deck with wall loss of 50% at 6 o’clock position. The length of the defect is approximately 200mm long. The repair section of the piping is located in close proximity to another 12” pipe.

Clock Spring reinforcement sleeve was used as a repair method using the hand spool technique.

Field report featuring major rehabilitation project (over 654 locations) in process plant to correct pipe corrosion at support contact points. Project utilized repairs at over 654 pipe support locations. Each repair installed <15 minutes.

Field Report of offshore leak repair in West Africa. 6” inlet pipe on discharge pump with small pin hole leaks close to “tee” girth weld. Repair required temporary shut down of the pump whilst area manually cleaned and pin hole sealed with leak sealing compound. Clock Spring Contour application over the complete complex tee geometry and all affected girth welds. Repair designed in accordance to ISO TS24817.

30” main oil export line
70 bar operating pressure
+70°C operating temperature
Repair Application:
Field report exploring repair of a girth weld repair on a high temperature oil export line in West Africa. Defects featured general external corrosion at girth welds due to poor application of field joint coatings. Standard girth weld bridging technique utilised with high temperature Clock Spring system, suitable for up to 120°C service temperature.

Field report of pipe support installation in Luxembourg on new pipeline fitted during line construction to prevent all future problems associated with crevice, galvanic corrosion and erosion.

Field report of offshore structural repair in Middle East featuring 8 metre repair length with severe external corrosion (up to 80%) metal loss on 14″ heavy wall structural cross member designed to hold riser support clamps. Solution features engineered heavy wall composite sleeve, extensive filler application and molding to rebuild pipe surface, more…