JOH-KGN001-20071212-JvW-X1 FABRICATION OF FLOW CONTROL VALVES FOR OLKARIA I GEOTHERMAL POWER PLANT Fredrick Olwal - Snr Technician and Joseph Odhiambo - Snr Foreman G2G Innovation Seminar, PrideInn Paradise Beach Hotel 18th – 22nd JUNE 2018

FREDRICK O. OLWAL Technician - Olkaria Qualifications: JOH-KGN001-20071212-JvW-X1 FREDRICK O. OLWAL Technician - Olkaria Qualifications: - Diploma in mechanical engineering Responsibilities: His main focus is designing, installation and maintenance of water line system and water pumping units in the whole geothermal area. Key milestones/achievements include: Designed and installed of brine pump station at Olkaria I Designed and installed mobile pump stations example; OW-915, OW-919, OW-914 Overhaul of a ten stage centrifugal pump for Eburru pump station Overhaul of a four-stage centrifugal pump for Olkaria pump station

Presentation Outline INTRODUCTION CURRENT SITUATION DEVELOPED SOLUTION JOH-KGN001-20071212-JvW-X1 Presentation Outline INTRODUCTION CURRENT SITUATION DEVELOPED SOLUTION COST BENEFIT ANALYSIS CONCLUSION & RECOMMENDATIONS 1 2 3 4 5

INTRODUCTION Process improvement done at Olkaria I power station JOH-KGN001-20071212-JvW-X1 INTRODUCTION Process improvement done at Olkaria I power station Fabrication of distribution valves at the cooling towers At this time of this project, the installed valves were worn out due poor quality iron(cast iron) This resulted to: low efficiency of the CT Frequent CT failure Increased temperature of auxiliary cooling water Main objective was to ensure elimination of down time caused by valve failure

Steam flow schematic diagram Pressure 4.2 bars Temperature 159ºC Cooled water temp~24ºC back to condenser Distribution Valves are located on top of CT Distribution Valves

CURRENT SITUATION. GRP pipe Flow control valve

CURRENT SITUATION Cont’ Worn out valve Worn out valve flange

CURRENT SITUATION Cont’ On site attempt to repair Dilapidated valve using Fibreglass repairs. The original valve had a rubber lining to protect the bare metal- Cast Iron from corrosion and erosion due to the acidic geothermal liquid (condensate)

DEVELOPED SOLUTIONS Reference drawing

DEVELOPED SOLUTION Cont’ This is a new valve made of cast iron. Fabricated one was made from stainless steel The cylindrical stainless steel used were left pipes from completed projects

DEVELOPED SOLUTION The KenGen acquired a new laser/ Plasma cutting machine. Made it easy to cut different shapes. It also shortened the time taken for the fabrication. Left over pipes obtained from Olk. 4 and 1AU projects.

DEVELOPED SOLUTION Cont’ Work in progress Cut flanges from exploded part

DEVELOPED SOLUTION Cont’ Valve body and flanges welded together

DEVELOPED SOLUTION Cont’ Completed valves awaiting transportation to site

Final installation’ From this To this Installed fabricated valve as it appears in its working position.

COST BENEFIT ANALYSIS ITEM COST Cost of a new valve from original Equipment manufacture before importing KES 720,000 Cost of procuring the valve locally in the country with lead time of 3 months KES324,800   Cost of internally fabricating Welding rods 10kg , grinding and cutting discs 5 pieces each 6,500 Labour for two technicians for seven days 147,500 Total 153,500 Typical loss on plant during valve failure for one day (24hrs)for one unit, Cost per unit KES 2.37 Net output units 13,000 kw/h Hourly cost (2.37*13000) KES 30,810 Total revenue lost in a day (30, 810*24) for one valve KES 739,440. Incase six vaves are worn out Total revenue lost for six valves Kes 739,440*6 KES 4,436,640

These valves to be fabricated within the company’s RECOMMENDATIONS These valves to be fabricated within the company’s workshops where possible It is also recommended that such process improvements be encouraged and staff empowered to explore and initiate such processes. Company to encourage effective use of left over materials from completed projects instead of taking them to scrap .  

CONCLUSION The internally fabricated valves are cheaper It takes shorter time to fabricate They are less susceptible to corrosion hence long lasting Made of stainless steel.

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