WORK REPORT FOUNDATION REPAIR AND REGROUT NUOVO-PIGNONE 6HE COMPRESSOR ENAGÁS BARCELONA PORT. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 1

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1 WORK REPORT FOUNDATION REPAIR AND REGROUT NUOVO-PIGNONE 6HE COMPRESSOR ENAGÁS BARCELONA PORT REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 1

2 Customer: Location: Project: Equipment: Pignone Española Global Services S A /Enagás S A Barcelona Gasification Plant, Barcelona Port, Spain Foundation repair and regrouting of C-2002-A. Nuovo Pignone 6HE reciprocating compressor, driven by a Siemens electric motor of 2,974 kw at 375 rpm Work Period: Mobilization 16 July 2001 Completion 03 August Project Summary 1.1 This compressor, originally installed in 1978, had been suffering from vibration and misalignment problems for several years. In an attempt to correct these problems, some partial regrouting had been carried out, but with cement-based products. 1.2 Alphatec Engineering, together with Pignone Española, offered a complete and comprehensive repair of the foundation by the pressure injection of epoxy adhesives and high tensile strength steel reinforcement, removal of the existing grout under both compressor and motor, support of the compressor in its existing position, re-alignment of the compressor with jacking screws, and placement of epoxy grout to properly support the compressor base, and motor bedplate. 1.3 When the motor was removed for overhaul, it became apparent that considerable corrosion of the baseplate had taken place, which exacerbated the alignment problems. Since a complete regrout of the baseplate was not feasible, the grout was chipped out to about 50 mm from the inside edge, to allow for seal grouting all round. Corrosion inhibitors were injected to stabilize the position of the bedplate. 1.4 Corrosion of the rebar in the vicinity of the high tension cabling to the motor was also discovered, and rectified with a corrosion inhibiting repair system. 1.5 Confirmation of the compressor alignment, and final alignment of the motor to the compressor, was carried out by Pignone Española. 1.6 The alignment of the compresor should now be close to original specifications, and the epoxy grout can be expected to maintain the position of the bedplate, and thus the alignment, for 15 to 20 years. 1.7 Cracks and cold joints in the foundation were repaired by epoxy injection. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 2

3 1. This compressor is a Nuovo Pignone 6HE gas compressor in natural gas service at Energas Barcelona Gasification Plant. 2. The original cement grout was in bad condition,and some repairs had been carried out in the past, using cementitious materials again. 3. The compressor was taken out of service on 14 July 2001 for mechanical overhaul, regrouting, and foundation rehabilitation. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 3

4 4. The motor foundation was in poor condition, with evidence of corrosion induced damage on all surfaces. 5. Corrosion rates around large electrical machinery are often exaggerated by the stray currents and induced currents in the concrete. Here, the expansion forces resulting from the rebar corrosion have been sufficient to shear the surrounding concrete conpletely. 6. The motor was removed from its baseplate, and taken away for overhaul in a separate facility. Alphatec Engineering work commenced on 17 July, and the first job was to chip away the cement grout embedding the baseplate. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 4

5 7. The chipping work revealed some areas of considerable corrosion under the baseplate, but it was decided that no remedial action was required, other than sealing the base to ensure no further corrosion activity. 8. At the same time, 50 mm ø holes 4 m deep were drilled each side of the baseplate. The objective of these holes is to gain access to the interior of the foundation for injection of the epoxy resin, and to create a space in which a high-tensile strength reinforcing bar can be placed. 9. The damaged concrete around the outside of the motor plinth was also chipped out by pneumatic chippers. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 5

6 10. After drilling the motor plinth injection holes, similar holes were drilled through the centre of the cylinder head support plinths, to a depth of approximately 3.5 m. 11. Removal of the main grout around the compressor crankcase commenced on 24 July. 12. Once the anchor bolts had been loosened, removal of the grout under the crossheads and crankcase flanges commenced. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 6

7 13. As the grout was removed in any area, small epoxy pads were prepared, and cylindrical jacking screw support blocks set in place to provide proper support for the equipment. Once the compressor was completely supported on the jacking screws, the alignment was checked and adjusted. 14. After all injection holes were completed, the high-tensile strength rebar was cut to size, injection and vent tubing attached, and the bar set in place in each hole. 15. Each hole was sealed using Alphatec 800 epoxy grout to give pressure resitance of up to 300 bar. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 7

8 16. Pressure injection was carried out on 30 July. The compressor block was injected first, followed by the motor foundation, and then the cylinder head support plinths. 17. Several cracks in the upper area of the compressor block showed satisfactory resin flow-out, but the cold joints showed little or no flow-out. This simply indicates that the internal conditions were so bad that substantial pressure could not be built up. 18. This crack was in the first stage cylinder head support plinth, coupling end, and extended virtually completely around the plinth. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 8

9 19. Formwork was prepared to contain the new epoxy grout, braced firmly, and sealed inside to prevent resin leakage. 20. A broken anchor bolt on the 1st stage cylinder head support plate, free end, was chipped out, and a replacement supplied by Pignone. Note the isolation around the upper part of the bolt, to allow for proper tightening and bolt extension. 21. While the formwork was being set in place, the compressor crankcase mechanical overhaul was proceeding. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 9

10 22. Grout containing forms were set in place around the inside of the motor basseplate, as well as the outside. 23. Grout materials were carried up to the working platform, to allow for mixing close to the place of pouring. 24. The grout was mixed and poured to embed the various bases up to the optimum level. This photo shows some injection tubing that was used to pump a corrosion inhibitor around the motor base frame. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 10

11 25. After an overnight cure the forms were removed, and sharp edges removed. 26. The cylinder head support bases were grouted up to their top surfaces. 27. The motor was returned and remounted a few days after the grout had been poured. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 11

12 28. Due to the large mass of grout, and to the stress risers provided by the anchor bolts going through the grout, 3 cracks appeared in the cured grout. This is a stress-relieving mechanism, an once repaired, is as strong as the original material. 29. The repair process consists of drilling a small hole (16 mm ø) across the crack, inserting a mechanical packer, and injecting Alphatec 800 resins. 30. Finally, a coat of epoxy paint was applied all around the upper part of the foundation, and a coat of acrylic paint applied to the remainder. REPORT NO: V-011 DATE: 6 August 2001 PAGE NO: 12

13 ALPHATEC ENGINEERING HISPANIA SL PO BOX 58 PUZOL 46530, VALENCIA, SPAIN Tel:(34) Fax: (34) Customer: Project: Location: Item: Date: Drawn by: Pignone/Enagas C-2002-A regrout Barcelona Plant Foundation repair, pressure injection, & regrout proposal 11 July 2001 GDG

14 Alphatec Engineering Hispania SL CUSTOMER: Pignone Española Global Services SA PROPOSAL: 0107/103 END-USER: Enagas EQUIPMENT: C-2002 A Natural Gas Compressor LOCATION: Barcelona Port SCOPE: Regrout & Foundation Repair DATE 17-Jul 18-Jul 19-Jul 20-Jul 21-Jul 22-Jul 23-Jul 24-Jul 25-Jul 26-Jul 27-Jul 28-Jul 29-Jul 30-Jul 31-Jul 1-Aug 2-Aug 3-Aug 4-Aug DAYS Description Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat Sun Mon Tue Wed Thu Fri Sat 1 mobilization & safety training 2 diamond core drilling 3 chip & drill around motor baseplate 4 chip 4 corners main foundation & motor baseplate 5 epoxy pads for jacking screws 6 chip centre area of foundation & cylinder supports 7 epoxy pads for jacking screws & Alphapads 8 pressure injection 9 alignment & formwork construction 10 1st pour epoxy grout 11 2nd pour epoxy grout 12 remove forms 13 remove jacking screws & fasten anchor bolts 14 demobilization DAYS DATE 17-Jul 18-Jul 19-Jul 20-Jul 21-Jul 22-Jul 23-Jul 24-Jul 25-Jul 26-Jul 27-Jul 28-Jul 29-Jul 30-Jul 31-Jul 1-Aug 2-Aug 3-Aug 4-Aug Date: 09 Jul 2001