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Steam Trap Inspection vs. Monitoring Comparing Preventative and Predictive Maintenance Approaches

Prepared by Embedded Energy Technology

August 15, 2014 Pittsburgh, PA

Contents Executive Summary .............................................................................................................................................. 2

Overview ............................................................................................................................................................... 3

Steam Trap Basics ............................................................................................................................................ 3

Failure Modes – Closed or Open .................................................................................................................. 3

Failed-Open Selected as the Basis for Comparison ...................................................................................... 3

Maintenance Approaches .................................................................................................................................. 3

Input Parameters and Assumptions ....................................................................................................................... 5

Inputs ................................................................................................................................................................ 5

Exclusions ......................................................................................................................................................... 7

Formulas for Calculated Values........................................................................................................................ 8

Results for Low Pressure Systems (<15 psig) ...................................................................................................... 9

Results for Medium Pressure Systems (15-125 psig) ......................................................................................... 10

Results for High Pressure Systems (>125 psig) .................................................................................................. 11

Sources ................................................................................................................................................................ 12

Appendix 1: Input Tables .................................................................................................................................. 13

Energy and Costs ........................................................................................................................................ 13

Steam Trap Failure Rates ............................................................................................................................ 13

Appendix 2: Detailed Cost Results Tables ........................................................................................................ 14

EmbeddedEnergyTechnology.com

Page 1

Executive Summary

Steam traps play an essential role in steam systems and must be routinely maintained to minimize energy losses, system damage, and personnel risks. This analysis provides the overall cost per trap associated with various maintenance approaches over a 12 year period and compares them with the losses of an unmaintained system to help determine the most cost effective approach for low, medium, and high pressure applications.

The maintenance programs selected include periodic system wide steam trap replacements (1, 3,or 6 years), periodic inspections (Monthly, Bi-Monthly, and Annually), and electronic monitoring. Results are provided for low pressure (<15 psig), medium pressure (15-125 psig), and high pressure systems (125-200 psig).

The cost of an unmaintained trap in a low pressure system is estimated at $152 per year and the findings suggest that a six-year replacement program is optimal, providing an estimated annual savings of $79 per trap including a 60 Therm reduction in fuel consumption.

The cost of an unmaintained trap in a medium pressure system is estimated at $681 per year. For these systems, either a three-year replacement program or a monitoring solution can provide savings of over $500 per trap annually, including over 300 Therms in energy savings alone.

The cost of an unmaintained trap in a high pressure system is estimated at $1,450 per year. A monitoring solution is the most cost effective option, providing an estimated savings of $1,265 annually including a 792 Therm reduction in fuel consumption.

Regardless of the system type, the findings show that in all cases almost any type of steam trap maintenance program will pay for itself by preventing steam losses. In addition to the financial benefits, a good program will improve system reliability and uptime while reducing negative environmental impacts.


Page 2

Overview Steam Trap Basics Steam traps perform the crucial function of removing condensate and air from steam, helping to ensure the efficient, safe, and reliable operation of a steam system. There are many different designs that use either mechanical, thermostatic, or thermodynamic mechanisms but all are intended to provide maximum purification with minimal steam loss.

Failure Modes – Closed or Open Steam traps can fail in one of two ways – “closed” and “open”. When they fail-closed1, condensate stays in the system and can cause issues reaching operating temperature, reduced responsiveness, and eventually water-hammer and corrosion. These failures can all have a very large negative impact on operating costs and risk (water-hammer can cause catastrophic failures and is a deadly safety hazard). When steam traps fail-open2 (either partially or fully) they expel good, usable steam from the system - turning it into waste along with the water and energy that went into producing it.

Failed-Open Selected as the Basis for Comparison This analysis is based on failed-open traps because the costs associated with these failures are directly correlated with system pressure and energy consumption. Open failures are also the most common. Although the impact of failed-closed steam traps can be significant, it can involve multiple components beyond the steam trap itself and will vary from one system to another.

Maintenance Approaches There are two approaches to keeping a system and its components operating properly: reactive, and proactive. The “reactive” approach is the most basic and involves repairing or replacing items when they break. This is a simple way to operate (in that there is little required in the way of planning or tracking) but can become costly due to unexpected downtime, labor costs, high inventory requirements, damage to downstream components, and losses that go undetected for long periods.

A “proactive” focuses instead on reducing/eliminating possibilities for failure. Replacing *every* component on a short, fixed schedule would be an example of a very proactive, and excessively costly, approach that would nonetheless keep failures to a minimum. It’s possible to economize the aforementioned approach while still keeping failures to a minimum by incorporating information.

The “preventative” approach tailors schedules and activities by component (or component type) by incorporating relatively static information such as manufacture recommendations, usage, and past experience.

The “predictive” approach is a further refinement that uses frequently updated information provided directly from the component (such as RPM from an electric motor) or attached sensors (i.e. temperature values, sound levels, vibration).

1 Failed-closed condition is commonly labelled “Plugged” or “Blocked” in steam trap surveys 2 Failed-open condition is commonly labelled “Blow(ing) Through” or “L(eaking)” in steam trap surveys


Page 3

This whitepaper compares “reactive”, “preventative” and “predictive” approaches applied specifically to steam traps. It examines the following variations:

• “Do Nothing” – Reactive approach for completely unmaintained system • “Replace Annually” – Proactive approach, replacement of all steam traps on an annual basis, no

inspection or monitoring • “Replace Every 3 Years” - Proactive approach, replacement of all steam traps every 3 years, no

inspection or monitoring • “Replace Every 6 Years” – Proactive approach, replacement of all steam traps every 6 years, no

inspection or monitoring • “Inspect Monthly” – Proactive approach, inspection of all steam traps every month and replacement of

failed traps within two weeks following inspection • “Inspect Bi-Monthly” – Inspection of all steam traps every two months, replacement of failed traps

within two weeks following inspection • “Inspect Annually” – Proactive approach, inspection of all steam traps once per year, replacement of

all failed traps immediately following • “Monitor” – Predictive approach, real-time electronic monitoring of steam traps with failure detection

occurring as-it-happens and replacement of failed traps within two weeks


Page 4

Input Parameters and Assumptions Inputs

• System Pressure3 – Each approach is evaluated using parameters for High, Medium, and Low Pressure systems are evaluated. In this case they are characterized as follows:

o Low Pressure – 15 psig and below 10.9 psig average (Btu/lb)

o Medium Pressure – 15-125 psig 85.9 psig average (888 Btu/lb)

o High Pressure – 125 psig and up 200 psig average (890 Btu/lb)

• Boiler efficiency – 80% • Operating Hours – 7,752 hrs/yr • Fuel Cost – $18 per MMBtu • Average Leak Rate – The maximum theortical leak rate, calculated using Napier’s equation assumes a

fully open orifice. This value is halved to reflect variability in real world conditions as verified in a study by Enbridge.

o Low Pressure Failed Trap – 6.9 lb/hr o Medium Pressure Failed Trap – 33.2 lb/hr o High Pressure Failed Trap – 75 lb/hr

• Trap Replacement Cost – o Low Pressure – $180 o Medium Pressure – $217 o High Pressure – $270

• Trap Inspection Cost – $254 • Monitoring Cost – $849 total for first 3 year, $100 per year thereafter • Trap Failure Probability – Information regarding steam trap failure percentages during an initial

survey is relatively plentiful. One often cited Federal Energy Management / DOE paper estimates that “approximately 20% of the steam leaving a central boiler plant is lost via leaking traps in typical space heating systems without proactive assessment programs.”5 The Steam Trap Survey Guide prepared by Oak Ridge National Laboratories for the Department of Energy adds that “a well-maintained steam system will typically experience a 10% trap failure in a 1-year period”6. In the worst documented cases, unmaintained systems have failure rates as high as 35%. At that level, a fully utilized steam system will generally be using all of its reserve capacity to make up for losses, necessitating some level of maintenance to prevent it from being non-operational. For that reason, even though the useful lifetime of a steam trap is only 6 years 7, our model caps failures at 33.6% even for a system that has gone unmaintained for 12 years.

3 Steam Trap Workpaper - Average pressure, Operating Hours, Trap Replacement Costs, and Leak Rates utilized above are either derived or sourced from this Workpaper. 4 Steam Traps 101 5 FEM Steam Trap Performance Assesment Page 1 6 Oak Ridge National Laboratory Steam Survey Guide ORNL/TM-2001/263 -3 7 Illinois Statewide Technical Reference Manual for Energy Efficiency Version 3.0 February 24, 2014. Page 253


Page 5

The results presented are agreeable with the 10% and 20% figures just mentioned, but these values alone are not enough to predict the performance of an ongoing maintenance program. Obtaining trap failure rates after various maintenances programs have been put into place was more difficult. These figures were obtained using the US Department of Energy’s “Steam System Assessment Tool”8. One of the capabilities of this tool is the prediction of steam trap failure rates based on the amount of time that has passed since the last inspection. A range of scenarios were plugged into the tool to extract values for failure rate over time for an average steam trap, the following graph shows the results.

Figure 1: Steam Trap Failure Rates as a Function of Time (Source - SSAT)

For an unmaintained system, the above failure rates are utilized as all of the traps in the system are assumed to be the same age. When traps are replaced, the failure rate resets to year zero values. For inspection programs, once replacements have been made, the traps in a system will have different failure rates based on their different ages – for example with an annual inspection program the failure rate for an average trap at the plant decreases slightly as it is assumed that 0.85% of the traps are new, and 98.15% are two years old.

• Average Duration of Failure: Because the failure rates represent a single point in time, the ‘average duration of failure’ is assumed to be half of the period – for example, if it is expected that 12 traps will fail in a year, it is assumed that these failures occurred at different times (on average 1 per month) so the average trap in the population, at the end of the year, will have been failed for 6 months. This analysis also assumes that when a failure is detected, the steam trap is replaced within an average of two weeks, an average of 1 week of losses is applied even if the failure is observed immediately. This assumption is applied to monthly/bi-monthly recurring inspection programs as well as monitoring. For annual programs the extra week of losses is not added as it is assumed that repairs will be conducted during a shutdown period. This assumption is applied to recurring inspection programs as well as monitoring.

8 Steam System Assessment Tool (SSAT) - Note that the SSAT has downloadable and online variations. Only the downloadable version provides steam trap failure rates. The total savings obtained using our assumptions are consistently 25% lower than those provided by SSAT which provides some affirmation on the validity and conservative nature of this analysis.


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Exclusions Some known factors have been excluded from this analysis. In some cases, such as items that may impact production facilities, this is done intentionally with the goal of keeping the results somewhat more universally applicable. In other cases, such as costs associated with corrosion, the ramifications can vary considerably and are difficult, if not impossible, to predict.

• Cost of downtime o A failure or replacement can have an impact on production costs that could vary considerably

depending on usage. • Inspection coverage

o Upwards of 20% of steam traps in a facility/building are difficult to access (or sometimes completely forgotten). It is also common for 30% or more of steam traps to be non-operational even during planned inspections. In some facilities it is not feasible to inspect during operation/production, so it is possible that the system is not being fully utilized during an inspection, or inspections are scheduled during a shutdown period where very little is operational.

• Misdiagnosis o There are a variety of inspection methods that can range from taking a look to employing

ultrasonic and FLIR technologies. The quality of results will depend on the thoroughness of the test, quality of the equipment (including monitoring equipment), and training/skill of the inspector. Failures can be missed, and good traps can be diagnosed as failing.

• Cost of makeup water or condensate cooling o Steam losses will cause increased demand for makeup water in boiler systems. In addition,

district steam systems without condensate returns may require condensate to be cooled before draining.

• Cost of corrosion o Steam traps help to prevent corrosion, so a system with failing traps will experience some

degree of corrosion over time that will eventually cause damage to other components outside the scope of this analysis.

• Costs associated with ‘failed closed’ traps o Refer to “Failed-Open Selected as the Basis for Comparison” on page 3

• Savings from insulation o The steam trap monitoring system used as the basis for this analysis is installed with

insulation jackets to generate savings from additional efficiency gains. These values and the jacket component have been excluded from this analysis which focuses only on steam trap failures.


Page 7

Formulas for Calculated Values

• Annualized Failure Rate (of Single Trap) =

𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑃𝑃𝐹𝐹𝑃𝑃𝑃𝑃𝐹𝐹𝑃𝑃𝐹𝐹𝐹𝐹𝐹𝐹𝑃𝑃𝑃𝑃 (𝑃𝑃) × 𝐴𝐴𝐴𝐴𝐹𝐹𝐹𝐹𝐹𝐹𝐴𝐴𝐹𝐹 𝐷𝐷𝐹𝐹𝐹𝐹𝐹𝐹𝑃𝑃𝐹𝐹𝑃𝑃𝐷𝐷 𝑃𝑃𝑜𝑜𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 (𝑚𝑚𝑃𝑃𝐷𝐷𝑃𝑃ℎ𝑠𝑠) ×1 𝑃𝑃𝐹𝐹𝐹𝐹𝐹𝐹

12 𝑚𝑚𝑃𝑃𝐷𝐷𝑃𝑃ℎ𝑠𝑠

• Annual Steam Loss (Therms) =

𝐴𝐴𝐷𝐷𝐷𝐷𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐴𝐴𝐹𝐹𝐴𝐴 𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝑅𝑅𝐹𝐹𝑃𝑃𝐹𝐹 × 𝑂𝑂𝑂𝑂𝐹𝐹𝐹𝐹𝐹𝐹𝑃𝑃𝐹𝐹𝐷𝐷𝐴𝐴 ℎ𝐹𝐹𝑠𝑠.× 𝐵𝐵𝑃𝑃𝐹𝐹𝐹𝐹𝑃𝑃� ×

1𝐵𝐵𝑃𝑃𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝐸𝐸𝑜𝑜𝑜𝑜.

× 𝐴𝐴𝐴𝐴. 𝐿𝐿𝐹𝐹𝐹𝐹𝐿𝐿 𝑅𝑅𝐹𝐹𝑃𝑃𝐹𝐹 ×1 𝑇𝑇ℎ𝐹𝐹𝐹𝐹𝑚𝑚

100,000 𝐵𝐵𝑃𝑃𝐹𝐹

• Steam Loss ($) =

𝐹𝐹𝐹𝐹𝐹𝐹𝐹𝐹 𝐶𝐶𝑃𝑃𝑠𝑠𝑃𝑃 × 𝐴𝐴𝐷𝐷𝐷𝐷𝐹𝐹𝐹𝐹𝐹𝐹 𝑆𝑆𝑃𝑃𝐹𝐹𝐹𝐹𝑚𝑚 𝐿𝐿𝑃𝑃𝑠𝑠𝑠𝑠 (𝑇𝑇ℎ𝐹𝐹𝐹𝐹𝑚𝑚𝑠𝑠) ×1 𝑀𝑀𝑀𝑀𝐵𝐵𝑃𝑃𝐹𝐹

10 𝑇𝑇ℎ𝐹𝐹𝐹𝐹𝑚𝑚𝑠𝑠


Page 8

Results for Low Pressure Systems (<15 psig) 3-6 year replacement program or annual inspections provide lowest overall cost per steam trap

An unmaintained medium pressure system has an average annual cost per steam trap of $152.

A six year replacement program works out to be the lowest cost option for low pressure systems at $73 per trap, resulting in annual savings of $79 per trap including 60 Therms. The financial impact of steam losses per trap is relatively low compared to the cost associated with inspection or monitoring. In some cases a replacement program may be unfeasible or excessively costly due to access restrictions, tenant comfort, production concerns, etc. so it may still be prudent to implement a more proactive or predictive program.

Reactive Predictive

Do Nothing Replace Annually

Replace Every 3 Yrs.


Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEARS 1-5 Total Cost Per Trap 192$ 924$ 271$ 192$ 1,531$ 786$ 254$ 1,070$ YEARS 6-12 Total Cost Per Trap 1,631$ 1,294$ 693$ 685$ 2,279$ 1,255$ 909$ 835$ YEARS 1-12 Total Cost Per Trap 1,823$ 2,218$ 964$ 877$ 3,810$ 2,042$ 1,163$ 1,906$ AV. PER YR. Steam Loss (Therms) 84 3 11 24 4 6 35 2 AV. PER YR. Steam Loss ($) 152$ 5$ 20$ 43$ 8$ 10$ 62$ 3$ AV. PER YR. Invest ($) Inspect/Replace/Monitor -$ 180$ 60$ 30$ 310$ 160$ 35$ 155$ AV. PER YR. Annual Cost Per Trap 152$ 185$ 80$ 73$ 318$ 170$ 97$ 159$

Proactive: PreventativeSummary of Per-Trap Costs LP (<15 psig)


Page 9

Results for Medium Pressure Systems (15-125 psig) 3 year replacement program, monitoring, or bi-monthly inspections provide lowest overall cost per steam trap

An unmaintained medium pressure system has an average annual cost per steam trap of $681.

A three year replacement program or a monitoring solution are the lowest cost options overall for medium pressure systems, with total annual cost per steam trap of $159 and $169 respectively, resulting in annual savings of over $500 per trap including over 300 Therms. Bi-monthly inspections are also a feasible alternative with a monthly cost of $208 per steam trap.

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEARS 1-5 Total Cost Per Trap 860$ 1,194$ 627$ 860$ 1,584$ 855$ 646$ 1,090$ YEARS 6-12 Total Cost Per Trap 7,321$ 1,672$ 1,337$ 1,893$ 2,576$ 1,645$ 3,144$ 981$ YEARS 1-12 Total Cost Per Trap 8,181$ 2,866$ 1,963$ 2,752$ 4,160$ 2,500$ 3,790$ 2,071$ AV. PER YR. Steam Loss (Therms) 379 12 51 107 19 26 155 8 AV. PER YR. Steam Loss ($) 682$ 22$ 91$ 193$ 35$ 47$ 279$ 15$ AV. PER YR. Invest ($) Inspect/Replace/Monitor -$ 217$ 72$ 36$ 312$ 162$ 37$ 157$ AV. PER YR. Annual Cost Per Trap 682$ 239$ 164$ 229$ 347$ 208$ 316$ 173$

Proactive: PreventativeSummary of Per-Trap Costs MP (15-125 psig)


Page 10

Results for High Pressure Systems (>125 psig) Monitoring provides lowest overall cost per steam trap

An unmaintained high pressure system has an average annual cost per steam trap of $1,450.

Implementing a monitoring solution is the lowest cost option for high pressure systems with total annual cost per steam trap of $192, resulting in annual savings of $1,265 per steam trap, including 792 Therms. The financial impact of steam losses per trap is very high compared with the costs associated with inspection or monitoring, so the most attractive options minimize that loss.

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEARS 1-5 Total Cost Per Trap 1,829$ 1,582$ 1,142$ 1,829$ 1,659$ 955$ 1,215$ 1,118$ YEARS 6-12 Total Cost Per Trap 15,570$ 2,215$ 2,268$ 3,642$ 3,007$ 2,209$ 6,384$ 1,192$ YEARS 1-12 Total Cost Per Trap 17,399$ 3,797$ 3,410$ 5,471$ 4,666$ 3,165$ 7,599$ 2,310$ AV. PER YR. Steam Loss (Therms) 806 26 108 228 41 55 330 18 AV. PER YR. Steam Loss ($) 1,450$ 46$ 194$ 411$ 74$ 99$ 594$ 32$ AV. PER YR. Invest ($) Inspect/Replace/Monitor -$ 270$ 90$ 45$ 315$ 165$ 40$ 160$ AV. PER YR. Annual Cost Per Trap 1,450$ 316$ 284$ 456$ 389$ 264$ 633$ 192$

Proactive: PreventativeSummary of Per-Trap Costs HP (>125 psig)


Page 11

Sources

Harrell, Greg. “Steam Survey Guide ORNL/TM-2001/263” Oak Ridge National Laboratory. May 2002.

Hooper, Frederic. “Predictive Maintenance of Steam Traps: Combining Demand Side Management and Performance Contracting” International District Energy Association. Jun., 1995, Oct., 1997.

“Illinois Statewide Technical Reference Manual for Energy Efficiency Version 3.0” Feb., 2014.

“Operations and Maintenance Best Practices release 3.0” Federal Energy Management Program. Aug., 2010.

"Steam System Tool Suite: Steam System Assesment Tool (SSAT)” Advanced Manufacturing Office http://www1.eere.energy.gov/manufacturing/tech_assistance/software_ssat.html

“Steam Trap Performance Assessment DOE/EE-0193” Federal Energy Management Program. Jul.,1999.

“Steam Trap Workpaper EEA Report No. B-REP-05-599-21E” EEA, Inc. on behalf of Southern California Gas Company, Dec., 2006.

“Steam Traps 101” National Grid. Aug., 2013. http://www.steamtrapsystems.com/documents/20130828SteamTraps101.pdf


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http://www1.eere.energy.gov/manufacturing/tech_assistance/software_ssat.html

http://www.steamtrapsystems.com/documents/20130828SteamTraps101.pdf

Appendix 1: Input Tables

Energy and Costs HP (>125 psig) MP (15-125 psig) LP (<15 psig)

Average Pressure 200 85.9 10.9

Btu/lb steam 837 888 953

Boiler Efficiency 80% 80% 80%

Operating Hours 7752 7752 7752 Average Leak Rate

(lb/hr) 75 33.2 6.9

$/MMBtu $18 $18 $18

Trap Replacement Cost $270 $217 $180

Trap Inspection Cost $25 $25 $25

Steam Trap Failure Rates

Base

YEAR 1 0.85%

YEAR 2 2.67%

YEAR 3 4.53%

YEAR 4 5.46%

YEAR 5 6.39%

YEAR 6 9.62%

YEAR 7 11.23%

YEAR 8 12.85%

YEAR 9 21.21%

YEAR 10 33.64%

YEAR 11 33.64%

YEAR 12 33.64%


Page 13

Appendix 2: Detailed Cost Results Tables


Page 14

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEAR 1 Leak / Blow ThroughProbability 0.85% 0.85% 0.85% 0.85% 0.85% 0.85% 0.85% 0.85%Av. Duration (Months) 6 6 6 6 0.75 1.25 6 0.25Annualized (P*(D/12)) 0.42% 0.42% 0.42% 0.42% 0.05% 0.09% 0.42% 0.02%

CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 849.00$ Replacement -$ 180.00$ -$ -$ 0.76$ 0.76$ 0.76$ 0.03$ Steam Loss 4.87$ 4.87$ 4.87$ 4.87$ 0.61$ 1.01$ 4.87$ 0.20$

YEAR 1 Total Costs 4.87$ 184.87$ 4.87$ 4.87$ 301.37$ 151.78$ 30.63$ 849.23$ YEAR 2 Leak / Blow Through

Probability 2.67% 0.85% 2.67% 2.67% 2.66% 2.66% 2.66% 2.66%Av. Duration (Months) 7.9 6 7.9 7.9 0.75 1 6 0.25Annualized (P*(D/12)) 1.76% 0.42% 1.76% 1.76% 0.17% 0.22% 1.33% 0.06%

CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ -$ Replacement -$ 180.00$ -$ -$ 2.39$ 2.39$ 2.39$ 2.39$ Steam Loss 20.16$ 4.87$ 20.16$ 20.16$ 1.91$ 2.54$ 15.25$ 0.64$



CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ -$ Replacement -$ 180.00$ 180.00$ -$ 4.03$ 4.03$ 4.03$ 4.03$ Steam Loss 41.27$ 4.87$ 41.27$ 41.27$ 3.21$ 4.28$ 25.65$ 1.07$









CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 180.00$ 180.00$ 180.00$ 8.09$ 8.09$ 8.09$ 8.09$ Steam Loss 91.84$ 4.87$ 41.27$ 91.84$ 6.44$ 8.59$ 51.52$ 2.15$

YEAR 6 Total Costs 91.84$ 184.87$ 221.27$ 271.84$ 314.53$ 166.67$ 84.61$ 110.23$

Proactive: PreventativeCost Per Trap: LP (<15 psig)


Page 15

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEAR 7 Leak / Blow ThroughProbability 11.23% 0.85% 0.85% 0.85% 10.13% 10.13% 10.13% 10.13%Av. Duration (Months) 11.14 6 6 6 0.75 1 6 0.25Annualized (P*(D/12)) 10.43% 0.42% 0.42% 0.42% 0.63% 0.84% 5.06% 0.21%







CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 180.00$ 180.00$ -$ 15.38$ 15.38$ 15.38$ 15.38$ Steam Loss 195.32$ 4.87$ 41.27$ 41.27$ 12.25$ 16.33$ 97.98$ 4.08$





Probability 33.64% 0.85% 2.67% 6.39% 20.81% 20.81% 20.81% 20.81%Av. Duration (Months) 12 6 7.9 11.1 0.75 1 6 0.5Annualized (P*(D/12)) 33.64% 0.42% 1.76% 5.93% 1.30% 1.73% 10.41% 0.87%



Probability 33.64% 0.85% 0.85% 0.85% 18.47% 18.47% 18.47% 18.47%Av. Duration (Months) 12 6 24.9 51 0.75 1 6 0.5Annualized (P*(D/12)) 33.64% 0.42% 1.76% 3.62% 1.15% 1.54% 9.24% 0.77%


YEAR 12 Total Costs 385.79$ 184.87$ 200.16$ 221.53$ 329.87$ 184.28$ 147.56$ 125.45$

Proactive: PreventativeCost Per Trap: LP (<15 psig)


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Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor


















YEAR 6 Total Costs 412.22$ 238.84$ 402.24$ 629.22$ 338.65$ 198.29$ 266.00$ 119.38$

Proactive: PreventativeCost Per Trap: MP (15-125 psig)


Page 17


Page 18

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor


















YEAR 6 Total Costs 876.74$ 316.45$ 663.98$ 1,146.74$ 373.61$ 244.10$ 528.98$ 132.62$

Proactive: PreventativeCost Per Trap: HP (>125 psig)


Page 19

Reactive Predictive




Inspect Monthly

Inspect Bi-Monthly

Inspect Annually

Monitor

YEAR 7 Leak / Blow ThroughProbability 11.23% 0.85% 0.85% 0.85% 10.13% 10.13% 10.13% 10.13%Av. Duration (Months) 11.14 6 6 6 0.75 1 6 0.25Annualized (P*(D/12)) 10.43% 0.42% 0.42% 0.42% 0.63% 0.84% 5.06% 0.21%

CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ -$ -$ 13.67$ 13.67$ 13.67$ 13.67$ Steam Loss 1,141.76$ 46.45$ 46.45$ 46.45$ 69.30$ 92.40$ 554.40$ 23.10$

YEAR 7 Total Costs 1,141.76$ 316.45$ 46.45$ 46.45$ 382.97$ 256.07$ 593.07$ 136.77$ YEAR 8 Leak / Blow Through


CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ -$ -$ 15.04$ 15.04$ 15.04$ 15.04$ Steam Loss 1,318.44$ 46.45$ 192.42$ 192.42$ 76.22$ 101.62$ 609.74$ 25.41$



CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ 270.00$ -$ 23.07$ 23.07$ 23.07$ 23.07$ Steam Loss 1,864.66$ 46.45$ 393.98$ 393.98$ 116.92$ 155.89$ 935.35$ 38.97$



CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ -$ -$ 32.49$ 32.49$ 32.49$ 32.49$ Steam Loss 3,002.74$ 46.45$ 46.45$ 547.02$ 164.70$ 219.60$ 1,317.59$ 54.90$

YEAR 10 Total Costs 3,002.74$ 316.45$ 46.45$ 547.02$ 497.19$ 402.09$ 1,375.08$ 187.39$ YEAR 11 Leak / Blow Through

Probability 33.64% 0.85% 2.67% 6.39% 20.81% 20.81% 20.81% 20.81%Av. Duration (Months) 12 6 7.9 11.1 0.75 1 6 0.5Annualized (P*(D/12)) 33.64% 0.42% 1.76% 5.93% 1.30% 1.73% 10.41% 0.87%

CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ -$ -$ 28.10$ 28.10$ 28.10$ 28.10$ Steam Loss 3,682.93$ 46.45$ 192.42$ 649.05$ 142.42$ 189.89$ 1,139.36$ 94.95$

YEAR 11 Total Costs 3,682.93$ 316.45$ 192.42$ 649.05$ 470.52$ 367.99$ 1,192.45$ 223.04$ YEAR 12 Leak / Blow Through

Probability 33.64% 0.85% 0.85% 0.85% 18.47% 18.47% 18.47% 18.47%Av. Duration (Months) 12 6 24.9 51 0.75 1 6 0.5Annualized (P*(D/12)) 33.64% 0.42% 1.76% 3.62% 1.15% 1.54% 9.24% 0.77%

CostsInspection -$ -$ -$ -$ 300.00$ 150.00$ 25.00$ -$ Monitoring -$ -$ -$ -$ -$ -$ -$ 100.00$ Replacement -$ 270.00$ 270.00$ 270.00$ 24.94$ 24.94$ 24.94$ 24.94$ Steam Loss 3,682.93$ 46.45$ 192.42$ 396.48$ 126.42$ 168.55$ 1,011.33$ 84.28$

YEAR 12 Total Costs 3,682.93$ 316.45$ 462.42$ 666.48$ 451.35$ 343.49$ 1,061.26$ 209.22$

Proactive: PreventativeCost Per Trap: HP (>125 psig)


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