1. JOH-KGN 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

2. FREDRICK O. OLWAL Technician - Olkaria Qualifications:
JOH-KGN 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

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

4. INTRODUCTION Process improvement done at Olkaria I power station
JOH-KGN 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

5. 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

6. CURRENT SITUATION.
GRP pipe
Flow control valve

7. CURRENT SITUATION Cont’
Worn out valve
Worn out valve flange

8. 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)

9. DEVELOPED SOLUTIONS
Reference drawing

10. 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

11. 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.

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

13. DEVELOPED SOLUTION Cont’
Valve body and flanges welded together

14. DEVELOPED SOLUTION Cont’
Completed valves awaiting transportation
to site

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

16. 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
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

17. 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 .

18. 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.

19. THE END