18.+Maintenance

Authors: Clark Beach, Zac Jones, Laura Medina, Cristina Rodriguez

=**"A living cell requires energy not only for all its functions, but also for the maintenance of its structure." Albert Szent-Gyorgyi ** =

=18.1 Chapter Goal =

Discuss the importance of maintenance and why there is an essential need for it.

=18.2 Introduction =

This chapter addresses maintenance in sustainable infrastructures. In order to really understand the analysis of maintenance, an in depth explanation of infrastructure and sustainability is required, and not to mention, what is the importance of maintenance is. Infrastructures are defined as the set of interconnected structural elements that provide framework supporting an entire structure of development [1]. It refers to the technical structures that support a society; some examples include: roads, water supply, telecommunications, and electrical grids. Sustainability is not eassily defined but it can be defined as the capacity to endure. A useful tool to have controled maintenance is through a Life-Cycle Cost Analysis which is a method of calculating a building project's expected operating, maintenance and replacement costs. In this report the maintenance of transportation, hydroelectric power, wind power and pipes will be addressed.

Maintenance is required to effectively reduce waste and run an efficient, continuous manufacturing operation or service operation. The cost of regular maintenance is very small when it is compared to the cost of a major breakdown at which time there is no service. In this chapter we will follow the outline on the previous page to address the ins and outs of this major part of any project. An example of how a great damage could have been avoided with proper maintenance was when in 2005 New Orleans was flooded becuase of the lack of maintenance on their Levee system with the effects of hurricane Katrina, category 3.Back in 2002 there had been a plan designed to reduce damages caused by possible floods and hurricanes. This strategy called for $14 billion in the construction or strengthening of levees around the city [2]. Despite the threat of floods, the Bush administration approved a budget of only $2 billion dollars for the program, using as pretexts the costs of the war in Iraq and homeland security. In consecuense, 80% of New Orleans was flooded, almost 6,000 people were injured and the amount committed to Katrina relief by the federal government was of $85 billion.Regarding infrastructure, the number of housing units damaged, destroyed, or inaccessible was of 850,791. If proper maintenance had been completed lives would have been saved and billions of dollars could have been used elsewhere.

The infrastructure in the US got an overall grade of "D" and would need $2.2 trillion in repairs and upgrades over the next five years to meet adequate conditions, according to the 2009 Report Card for America’s Infrastructure released by the American Society of Civil Engineers (ASCE) [3]. They claim that, "Decades of underfunding and inattention have endangered the nation's infrastructure." The highest grade received was a C+ for solid waste because of how hazardous waste is still being managed today. The condition of the nation's bridges receives the next highest grade, a C, while two categories, rail and public parks and recreation scored a C-. All other infrastructure categories were graded D or D-, including: aviation, dams, hazardous waste, inland waterways, levees, roads, schools, transit and wastewater. This report is created every 4 years and compared to the report in 2005 little progress has been made.

=18.3 Examples of infrastructure and their required maintenance =

**18.3.1 Transportation **


According to [|ASCE], there is a clear and existing need for an increased focus on transportation operations, and management at all levels – federal, state, regional, and local.
 * The need for more maintenance is shown in the aging transportation infrastructure is the result in the escalation of replacement costs. There is a growing congestion followed by a high number of accidents which are degrading the performance of the transportation systems in many areas of the country. Because of capacity limitations and costs of new constructions, maintenance and improvement of the existing transportation system are receiving more importance; not to mention that proper levels of maintenance ensure its continued service and reliability. Some key elements that would make the transportation systems more reliable and effective could include the following:


 * Maintaining systems in a state of good repair.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Routine traffic and transit operations.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Public safety response.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Asset management.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Work zone management.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Incident management.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Network and facility management.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Freight management operation.

In Costa Rica (CR), the maintenance of their transportation systems is run by the University of CR and [|LANAMME](//L//aboratorio Nacional de Materiales y Modelos Estructurales; which translates to Nacional Laboratory of Materials and Structural Models). Their goals include the stabilization and maintenance of roadways along with the creation of a set of paving guidelines specific to the country's climate. CR has been following the United State's guidelines, ASHTO, but the weather that the U.S. experiences is quite different from all of the rain and heat that Costa Rica experiences.

<span style="font-family: Arial,Helvetica,sans-serif;">18.3.2 Hydroelectric Power
"Operation and Maintenance of hydro power stations must aim at reducing failure rate by ensuring smooth operational level of the power utility. This can be done by adopting a timely preventive maintenance schedule regarding all vital areas of the power project. Engineers are well -advised here to follow the well-known dictum: Prevention is better than the cure."

<span style="font-family: Arial,Helvetica,sans-serif;">According to Best Practices in Operation & Maintenance of Hydro Power Stations [6], Hydroelectric power facilities should have regular inspections consisting of technical maintenance management in diagnostics, troubleshooting, O&M, hydroelectric power plant control, automation, and incident investigations. Key practices that should be regularly done are the preventive maintenance schedules covering all vital areas and plants, the detailed daily, weekly, monthly, quarterly, annually and capital maintenance sheets should be maintained, monitored and recorded properly. Regular structural maintenance should be done on the main parts of the plant; which are the water conductor system, turbine and the generator.

<span style="font-family: Arial,Helvetica,sans-serif;">Water storage and water conductor system comprising of intake, head race tunnel, surge shaft, emergency valves & pressure shafts, penstock, main inlet valves are a extremely vital part for the correct functioning of a hydro power plant.Due sudden changes in water flow, it is essential to attend to these plant & equipment very carefully by regularly testing the operation of the system/equipment i.e. intake gates, butterfly valves, excess flow device, surge equipment etc. Periodic physical inspection of water conductor system from inside as well as outside to know its condition, silt deposition, rusting/erosion of conduit system is very much essential to find out various changes due to aging factor, stresses developed due to water hammer etc. <span style="font-family: Arial,Helvetica,sans-serif;">Some of the additional points as mentioned below also need to be considered:
 * <span style="font-family: Arial,Helvetica,sans-serif;">Check for cavitation and erosion at top portion due to rushing of air during fill up.
 * <span style="font-family: Arial,Helvetica,sans-serif;">The inspection schedule for the durability of anticorrosive paints used.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Replacement schedule for various vulnerable parts such as bends, open conduits etc.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Due to humidity open conduit deteriorates from outside. Such inspection and cleaning should be carried out at regular intervals.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Timely operation and maintenance of the cranes and hoists.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Healthiness of control and protection for isolating gates/valves and for cranes/hoists.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Maintenance of trash-rack/intake gate filter.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Maintenance of communication systems, availability of power supply, equipment for emergency operations, approach roads etc.

<span style="font-family: Arial,Helvetica,sans-serif;">Due to cavitation there may be huge damages to turbine wheel causing adverse effect on performance and consequently efficiency; therefore regular inspection should be carried out and recorded. Desired purity level of hydraulic oil is to be maintained to give trouble free operations,and the history of each important part should be maintained. Other maintenance that should also be performed are:
 * <span style="font-family: Arial,Helvetica,sans-serif;">Polishing of the various under water parts of the turbines once in a year to minimize the white pitting.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Inspection and testing of the runners from experts to decide residual life so as to initiate action for procurement of runners for replacement.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Inspection of labyrinth seals in case of reaction turbines.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Painting of runner housing with anticorrosive I tar based paints.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Applying anti-erosion coating to the runner.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Checking of brake jet operation in power stations having turbines once in three months.

<span style="font-family: Arial,Helvetica,sans-serif;">The main parts of a generator are the stator and rotor winding, bearings and excitation system; these should be properly maintained. It is important that a cooling system is maintained to limit the rise in temperatures and consequently increase the life of the generator. Other maintenance that should also be performed are:
 * <span style="font-family: Arial,Helvetica,sans-serif;">Periodic checking of the foundations, tightening the bolts. Filling the foundations with epoxy.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Checking the vibrations periodically and history of the recorded readings gives guidelines for realignment, looseness if any, unbalanced electrical components, increase in bearing gaps, coupling misalignment, uneven stator -rotor air gap etc.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Periodic cleaning or replacement of the generator air coolers and bearing oil coolers to improve performance of the generator.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Testing of the protection system for its healthiness and correct operation.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Inspection for over heating, temperature rise etc.
 * <span style="font-family: Arial,Helvetica,sans-serif;">Inspection of circuits for protection, control circuits and mock trials of the fire fighting system along with evacuation system. Checking weight loss of the CO2 cylinders and replenish as per manual recommendations.

80% of electricity produced by [|ICE] (Instituto Constariquense de Electricidad; which translates to the Costarican Institute of Electricity) is originated by hydroelectric power [7]. This puts a great importance on these systems making its maintenance crucial. Once a year, one by one each generator will be turned off to have maintenance performed on it; insuring its efficiency and life-span.

18.3.3 Wind Power


As a result of highly variable weather and operational conditions, there is high mechanical stress on wind turbines. There is a costly need for maintenance required to provide a safe, cost effective and reliable power output with a good equipment life. Since the equiptment is so costly compared to other types of energy production the costs associated with its maintenance should really be looked at as an investment that will prevent its failure.

Wind power constitutes 4% of energy production in CR. Which may not be as significant when compared to hydroelectric power but it actually complements hydro power since the strongest winds are during dry season; when hydroelectric is not producing as much energy [9].

**18.3.4 Pipes**


<span style="font-family: Arial,Helvetica,sans-serif;">Maintenance is required in order to provide, transfer and process fluids in the vast network of pipelines in a safe and effective way.Pipelines are susceptible to attack by internal and external corrosion, cracking, third party damage and manufacturing defects. Unfortunately, they do not give out any audible warnings; therefore it is imperative that periodic inspections are carried out to prevent damage. These inspections are useful to evaluate the integrity of the piping and joints. Some inspection methods include visual, magnetic particle, radiography, and ultrasonic [11]. <span style="font-family: Arial,Helvetica,sans-serif;">A check list for such operation is shown below in Table 1.

<span style="font-family: Arial,Helvetica,sans-serif;">Table 1- Preventive maintenance check list [12]
 * ** Item ** || ** Frequency of Inspection ** || ** Mode of Inspection ** ||
 * 1. Stop valve/isolation valve glands || Every week during weekly shut down || Visual ||
 * 2. Flow control valves glands || Daily || Visual ||
 * 3. Safety valves || Weekly || Visual ||
 * 4. Pressure reducing valves || Weekly || Visual ||
 * 5. Steam traps || Daily || Visual ||
 * 6. Threaded and flanged joints (connected with vibrating machines) || Daily || Check bolts for tightness ||
 * 7. Clamps and brackets: (connected with vibrating machines) || Every shut-down || Check bolts for tightness ||
 * 8. Clamps and brackets: (in general) || Quarterly || Check bolts for tightness ||
 * 9. Hoses fixd to vibrating machines || Every shift || Check clamps for tightness and visual examination for external damage ||
 * 10. Hoses fixed to stationary machines || During each shut-down || Check clamps for tightness and visual examination for external damage ||
 * 11. All indoor pipes (overhead) || Quarterly || Visual examinations and cleaning of external surface ||
 * 12. All indoor pipes (in trenches, tunnels, etc.) || Quarterly || Visual examination for external damage and corrosion ||
 * 13. All outdoor pipes (overhead) || Half-yearly || Visual examination for external damage and corrosion ||
 * 14. All outdoor pipes (underground) || Every five years or so || Sample test: Visual examination after excavating certain portion to check the condition of caotings provided to measure the pipe wall thickness ||

=18.4 Conclusion=

<span style="font-family: Arial,Helvetica,sans-serif;">The importance of an effective maintenance program cannot be overlooked because it plays such an important role in the effectiveness of a system. <span style="font-family: Arial,Helvetica,sans-serif;">The cost of regular maintenance is very small when it is compared to the cost of a major breakdown at which time there is no production. It is crucial to have scheduled maintenance specific to every type of infrastructure.

=<span style="font-family: Arial,Helvetica,sans-serif;">18.5 References =

[1] Jack R. Benjamin & Associates (2010). Civil Infrastructure Management [Online] Available: <span style="background-attachment: initial; background-clip: initial; background-color: initial; background-origin: initial; background-position: 100% 50%; background-repeat: no-repeat no-repeat; cursor: pointer; padding-right: 10px;">[].

[2] Discovery Channel (2012). Facts About Katrina [Online] Available: http://dsc.discovery.com/convergence/katrina/facts/facts.html

[3] American Society Of Civil Engineers (2009). Report Card for America's Infrastructure [Online] Available: http://www.infrastructurereportcard.org/

[4] Transportation (2009). Photo: Transportation [Online] Available: http://www.mtho.webs.com/

[5] Times Union (2010). Photo: Closing up the Canal [Online] Available: http://www.timesunion.com/local/article/Photos-Closing-up-the-canal-805352.php

[6] Central Electricity Authority (2010). Best Practices in Operation & Maintenance of Hydro Power Stations [Online] Available: http://www.cea.nic.in/reports/hydro/best_practises/chapter-6.pdf

[7] & [9] Notes from personal CR journal

[8] Northern Development (2010). Photo: Wind Power [Online] Available:

http://www.northerndevelopment.bc.ca/explore-our-region/success-stories/northern-lights-college-training-tower-powers-wind-turbine-maintenance-program/

[10] KHL group (2012). Photo: Pipe Maintenance [Online] Available: http://www.khl.com

[11] John Van Rijn Development (2012). Maintaining Sewer Systems [Online] Available: http://www.indevelopment.nl/PDFfiles/maintainingSewerSystems.pdf

[12] New Age International (2012). Pipework Maintenance [Online] Available: http://www.newagepublishers.com/samplechapter/000347.pdf