HOUSTON\2332921.5 

## MEMORANDUM

TO: Melanie King, Environmental Protection Agency

DATE: January 27, 2010

RE: Management Practices for SI RICE Area Sources < 500 hp

P ROPOSED M ANAGEMENT P RACTICES AT A REA S OURCES

On March 5, 2009 EPA issued Proposed Revisions to Code of Federal Regulations T itle 40, Part 63, Subpart ZZZZ

("Proposed Rule") for certain Spark Ignited Recipr ocating Internal Combustion Engines ("SI RICE"). The Proposed Rule included management practices su ch as oil changes and spark plug replacements for certain SI RICE area sources. The Clean Air Act allows EPA to establish management practices based on Generally Available Control Technology (GACT) rather than MACT for area sources. EPA's proposed SI RICE management practices for exi sting area sources, however, far exceeded any standard maintenance practice requirements and in f act may increase the environmental impact of the industry by increasing waste and air emissions. Ea ch excessive oil change could generate up to 30 gal lons of waste used oil. For example, the Proposed Rule' s used oil change frequency could generate 430 gallons of additional waste oil from one Ajax 2SLB engine in one year. When considered across all affected engines, unnecessary oil changes could res ult in considerable additional waste.

In response to the Proposed Rule, Exterran, JW Powe r Company and CSI (EJC) submit the following oil and spark plug inspection, analysis, and change man agement practice recommendations. Based upon extensive industry preventive maintenance experienc e and current best practices developed and improved upon over many years, this document presents recomm ended oil and spark plug inspection intervals; parameters for changing the oil or replacing the sp arkplugs; and recordkeeping requirements. These recommendations have been prepared to ensure the op timal maintenance of existing SI RICE without creating unnecessary waste due to excess oil change s and vehicle miles traveled to remote facilities. For example, with the advent and application of synthet ic oils and synthetic oil blends, oil change interv als have been increased based on observed product perfo rmance. Improved lubricants combined with increased reservoir and pump capacities also allow for expanded oil change intervals. This proposal requires owners/operators to inspect engines at set intervals to determine whether an oil change or sp ark plug replacement is needed based upon the inspectio n parameters detailed below.

Although these recommendations are based upon apply ing management practices to SI RICE less than 500 hp, EPA should also consider expanding the appl ication of management practices to all SI area sour ce RICE, particularly those in rural locations. Shoul d engines > 500 hp be included within the scope of management practices, the associated time intervals for these engines should be extended to account fo r the additional capabilities (e.g., oil reservoir vo lume) for these engines.HOUSTON\2332921.5 Recommended Inspection Intervals and Analysis Param eters

Recommendations for inspection intervals and analys is parameters are discussed in this section, follow ed by tables that summarize the recommendations. Thes e tables use a tabular format similar to Subpart ZZZZ tables and provide recommendations for rule re visions. In addition to defined action levels, the proposed approach includes flexibility to adapt to evolving performance metrics or metrics applicable to a particular engine and lube oil. For example, addit ional advances in lubrication could result in performance metrics that are not consistent with sp ecification defined below. In this case, the opera tor could rely on an alternative action level based on the oil manufacturer's specified action level, or alternative monitoring techniques.

4SRB/4SLB <500 hp

4SRB/4SLB Spark Plug Inspection and Replacement. Industry best practices provide that owners/operators inspect the spark plugs or analyze spark performance at least every 1,440 hours of engine operation. This inspection ensures that the spark plug is able to continue to provide the nece ssary spark required to ignite the air/fuel mixture. Thi s assessment consists of a visual inspection of the plugs, or analysis of spark performance using standard dia gnostic instrumentation.

The spark plug is the most accessible power cylinde r component and can be the most relevant diagnostic utility available to detail conclusions regarding e ngine operating conditions. Should a spark plug electrode be worn or damaged, the air/fuel mixture may not be optimally combusted, potentially resulti ng in increased emissions, reduced engine power, and r educed efficiency. Visual inspection of the firing ends of each cylinder's spark plug can suggest a va riety of possible engine conditions. For example, a visual inspection of a spark-plug firing end may id entify oil or carbon fouling which indicates an eng ine component is experiencing high temperature or exces sive wear. If the spark plug is fouled it can be cleaned, regapped and returned to service. If the spark plug is worn, cracked or otherwise damaged th en replacement is necessary.

Depending upon engine size and configuration, spark voltage/performance may be best measured using a non-invasive diagnostic tool, in which case the spa rk plug does not have to be removed, to assess spar k plug performance. One tool that may be used for su ch an analysis is a piece of equipment capable of measuring whether the spark plug, spark plug wiring , spark plug coils and voltage have enough energy f or the spark plug to properly fire. Results of testin g can trigger the need to clean or replace plugs.

4SRB/4SLB Oil Inspection and Changing. The recommended management practices include changi ng the engine oil at least every 1,440 hours of engine ope ration. As an alternative to changing the oil, the operator may conduct an oil analysis at least every 1,440 hours of engine operation and document the findings and any actions required by the oil analys is. If any identified oil parameter in the oil ana lysis, as described below, falls outside the designed “Change Level”, the operator should change the oil within 30 days of receiving the analysis. The 30 day period i s necessitated by potential delays in accessing rem ote
sites.HOUSTON\2332921.5

The oil analysis and Change Levels recommended belo w identify parameters that indicate whether the oil is beginning to degrade beyond its useful life. Ni tration and oxidation are typical primary reactions that occur in the lubricants of natural gas-fired RICE. As these reactions occur, the additives that were originally blended with the oil to counteract this process are depleted and engine performance may decline, thereby increasing the possibility of engi ne malfunction or increased emissions. Key markers of oil depletion include:

 TAN - Total Acid Number (TAN) of the engine indicates t hat the acidity levels have increased beyond an acceptable threshold. This is typically caused by exhaust gases permeating from the combustion chamber and mixing with the lube oil, re sulting in nitration.
 Viscosity – Viscosity indicates the typical oil life degradat ion (increasing viscosity) or oil contaminants such as water (decreasing viscosity). A decrease in viscosity is a secondary indicator of oil contamination (% relative humidity is the primary indicator).
 Water (% relative humidity) - relative humidity is the primary indicator of wa ter contamination
in the oil.

If the oil analysis indicates that an oil attribute falls outside of any acceptable Change Level, as d escribed on the table below, the owner or operator will chan ge the oil within 30 days of receiving the analysis results. Alternatively, the owner or operator may follow the oil manufacturer's recommended parameter s and action levels. If the oil manufacturer's level s are followed the owner/operator must document the oil manufacturer's recommended change levels and whethe r the oil analysis results fall outside of such lev els at each inspection interval.

Natural Gas RICE Oil Change Levels

Oil Parameter Change Level A Oil Degradation Indicated by Parameter
TAN (mg/KOH/g) > 3.0 above new oil TAN Acidic content indicator

Vis @ 100C, (cSt) -20%/+30% change from new Oil viscosity

Water (%) > 0.5 Water contaminant indicator

A Owners and operators may follow the oil manufacture r's recommended change levels. If the oil manufact urer's levels are followed the owner/operator must documen t the oil manufacturer's recommended change levels and whether the oil analysis results fall outside of su ch levels at each inspection interval.

2SLB <500 hp

The engine configuration of the Ajax 2SLB RICE allo ws for an extended inspection interval for both spark plugs and oil inspections. Ajax 2SLB have an extended inspection interval because the power cylinder is separated from the crankcase and uses a sealed piston rod for the mechanical connection. Due to this engine configuration, no combustion blow by products get into the crank case to contaminate th e oil. The Ajax lubrication process is described fur ther in Appendix A. Ajax 2SLB are also slow speed, lower combustion engines, which means that the spar k plug fires less than and at a lower temperature t hanHOUSTON\2332921.5

a typical 4SRB or 4SLB engine, thus allowing extend ed intervals for the spark plugs.

2SLB Spark Plug Inspection and Replacement. Industry best practices provide that spark plugs fo r 2SLB should be changed or inspected at least every 4,320 hours of engine operation. Visual inspection of t he firing ends of each cylinder's spark plug can sugge st a variety of possible engine conditions. For ex ample, a visual inspection of a spark-plug firing end may identify oil or carbon fouling which indicates an e ngine component is experiencing high temperature or exces sive wear. If the spark plug is fouled it can be cleaned, regapped and returned to service. If the spark plug is worn, cracked or otherwise damaged th en replacement is necessary.

Depending upon engine size and configuration, spark voltage/performance may be best measured using a non-invasive diagnostic tool, in which case the spa rk plug does not have to be removed, to assess spar k plug performance. One tool that may be used for su ch an analysis is a piece of equipment capable of measuring whether the spark plug, spark plug wiring , spark plug coils and voltage have enough energy f or the spark plug to properly fire. Results of testin g can trigger the need to clean or replace plugs.

2SLB Oil Inspection and Change. The recommended management practices include changi ng the crankcase engine oil at least every 4,320 hours of engine operation. (See Appendix A for a descriptio n of the unique lubrication system associated with 2SLB engines.) As an alternative to changing the crankca se oil, the operator may conduct an oil analysis at le ast every 4,320 hours of engine operation and docum ent these findings. If the oil analysis indicates that any listed parameter exceeds or falls below the de signated Change Level, the operator will change the oil with in 30 days of receiving the analysis results. The recommended Change Levels for the 2SLB are the same as the 4SRB and 4SLB Change Levels described
above.

Alternative Monitoring

In the event that alternative products or technolog ies are utilized or become available that could ext end the inspection intervals or change levels currently proposed, requests shall be submitted to the Direc tor of the Office of Air Quality Planning and Standards, o r the Director's delegee, for approval of the alter native inspection intervals and/or change levels. Example s of such alternative products or analytical tools could include improved lubricants, high energy ignition s ystems, or premium precious metal tipped spark plug s. Draft language for petitioning the Director for alt ernative inspection intervals or change levels, bas ed upon alternative provisions in 40 C.F.R. § 63.6620, is provided below in the "Summary of Management
Practices" section.

Skip or Extended Period Monitoring

As referred to under current leak detection and rep air regulations such as NSPS Subpart VV (40 C.F.R. §60.483-2a), “skip period” monitoring could prove e ffective in dealing with premium oils and spark plu gs that are capable of further extending expected chan ge intervals. This also provides rule flexibility to adapt to technology advances. EPA could consider a form of skip or extended period monitoring that would allow for an affected facility to skip a requ ired interval or extend the intervals based uponHOUSTON\2332921.5

successful checks of the previous two intervals. F or example, if the change levels were not exceeded after two inspection periods, then inspection intervals c ould be extended by 1,440 hours after the next oil change. This would also reduce the amount of alter native monitoring requests submitted to the agency due to technology advances, such as the use of prem ium oils and plugs. Draft language for allowing sk ip period monitoring, based upon 40 C.F.R. § 60.483-2a , is provided below in the "Summary of Recommended Management Practices" section.

/Continued on the Next Page/HOUSTON\2332921.5 Summary of Recommended Management Practices

Based upon the foregoing, for engines 500 hp and sm aller, the following are recommended changes to proposed Table 2d of Subpart ZZZZ in Part 63 – Requ irements for Existing Stationary RICE Located at
an Area Source of HAP Emissions. This document foc uses on smaller units but EJC supports similar Management Practices for engines larger than 500 hp at area sources.

Table 2d

For each You must meet the following emission

or operating limitation at all times, except during periods of startup or malfunction You must meet the following emission or operating limitation during periods of startup or malfunction

1. NonEmergency 2SLB < 500 HP a. Change or inspect oil via oil analysis program* every 4,320 hours of engine operation. +
b. Change or inspect spark plugs every 4,320 hours of engine operation** a. Change or inspect oil via oil analysis program* every 4,320 hours of engine operation. +
b. Change or inspect spark plugs every 4,320 hours of engine operation**
2. Non-Emergency 4SLB < 500 HP a. Change or inspect oil via oil analysis program* every 1,440 hours of engine operation. b. Change or inspect spark plugs every 1,440 hours of engine operation.** a. Change or inspect oil via oil analysis program* every 1,440 hours of engine operation. b. Change or inspect spark plugs every 1,440 hours of engine operation.**
3. Non-Emergency 4SRB < 500 HP a. Change or inspect oil via oil analysis program* every 1,440 hours of engine operation. b. Change or inspect spark plugs every 1,440 hours of engine operation. ** a. Change or inspect oil via oil analysis program* every 1,440 hours of engine operation. b. Change or inspect spark plugs every 1,440 hours of engine operation. **

* The following are recommended parameters for the oil analysis. If analysis indicates that any of th ese parameters fall outside of the Change Level as indicated, the oil should be changed within 30 days of receiving t he analysis. Each analysis shall be documented with the actions taken as a result of the analysis.

Natural Gas RICE Oil Change Levels

Oil Parameter Change Level A Oil Degradation Indicated by Parameter
TAN (mg/KOH/g) > 3.0 above new oil TAN Acidic content indicator

Vis @ 100C, (cSt) -20%/+30% change from new Oil viscosity

Water (%) > 0.5 Water contaminant indicator

A Owners and operators may follow the oil manufacture r's recommended change levels. If the oil manufact urer's levels are followed the owner/operator must documen t the oil manufacturer's recommended change levels and whether the oil analysis results fall outside such levels at each inspection interval.HOUSTON\2332921.5

+ The oil analysis intervals is for the crankcase oi l on 2SLB engines ** During the inspection of the spark plug, a visua l inspection of a spark-plug firing end may identif y oil or carbon fouling which indicates an engine component is expe riencing high temperature or excessive wear. If th e spark plug is fouled it can be cleaned, regapped and returned to service. If the spark plug is worn, cracked or otherwise damaged then replacement is necessary. Depending u pon engine size and configuration, spark voltage/pe rformance may be best measured using a non-invasive diagnosti c tool, in which case the spark plug does not have to be removed, to assess spark plug performance.

Alternative Monitoring Program

(a) An owner or operator may petition the Director of the Office of Air Quality Planning and Standards

, or the Director's delegee, for alternative Change L evels or inspection intervals. If the Director, o r delegee, does not respond to the request within 60 days then the Alternative Monitoring Program is deemed approved.

(b) If you petition the Director for an alternative monitoring program, you must include the informati on described in paragraphs (b)(1) through (5) of this section.

(1) Identification of the specific parameters you p roposed to use as operating limitations;

(2) A discussion of how you will establish the uppe r and/or lower values for these parameters which wi ll establish the limits on these parameters in the ope rating limitations;

(3) A discussion of how you will establish the alte rnative inspection intervals;

(4) A discussion identifying the methods you will u se to measure and the instruments you will use to monitor any alternative parameters, as well as the relative accuracy and precision of these methods an d instruments; and

(5) A discussion of the relationship between the pr oposed alternative parameters and HAP emissions as well as how the proposed parameters compare to the operating limitations in Table 2d.

Skip Period Monitoring

(a) (1)An owner or operator may elect to comply wit h one of the alternative monitoring periods specifi ed in paragraph (b) of this section.

(2) An owner or operator must retain records of all alternative monitoring periods.

(b)(1) An owner or operator shall comply initially with the requirements for oil and spark plug inspec tions and changes or replacements as described in Table 2 d.

(2) After two consecutive inspection intervals list ed in Table 2d where the oil analysis does not fall outside the Change Levels and/or the spark plugs do not req uire replacement, an owner or operator may skip the first inspection interval after the next oil change and/or spark plug replacement, as applicable.HOUSTON\2332921.5

(3) After three consecutive inspection intervals li sted in Table 2d where the oil analysis does not fa ll outside the Change Levels and/or the spark plugs do not req uire replacement, an owner or operator may begin to skip two inspection intervals after the next oil ch ange and/or spark plug replacement, as applicable.

(4) Notwithstanding anything in this section, in no event shall an inspection interval exceed 8,760 operating hours.HOUSTON\2332921.5 APPENDIX A

AJAX 2SLB L UBRICATION S YSTEM

The recommended manufacturer practice for an Ajax 2 SLB requires an oil change on an annual basis for the crankcase lubrication system. Ajax 2SLB engine s have such an extended oil change interval because the power cylinder is separated from the crankcase and uses a sealed piston rod for the mechanical connection. Due to this engine configuration, no c ombustion blow by products get into the crank case to contaminate the oil. The lubrication process is d escribed further below.

The AJAX integral compressor uses 3 types of lubric ation: force feed, splash and flooded. The force f eed system is used to provide lubrication to the power and compression cylinders, and pressure packings. The cylinder lubrication is typically a major source in the contamination of the oil. In the AJAX the cyl inder lubrication is part of the force feed system and th e oil is consumable, meaning a small amount is consumed per day. As a result of the force feed sy stem, the contaminated oil from the combustion is n ot brought into the main crankcase lubrication system to contaminate bearings.

The splash method is used in the crankcase for the crank pins, main bearings, crossheads, crosshead pi ns, and other major internals. The splash system is con sists of a large volume of oil filling the crankcas e and using the engines crankshaft and rods to distribute the oil to crossheads. Since this system is seale d from the combustion gasses the manufacturer rates the cr ankcase oil change at 10,000 hours. In a conventio nal combustion engine the crankcase oil is contaminated by the combustion gasses blowing by on rings and the oil used to lubricate the cylinder walls being recirculated through the oiling system. The AJAX eliminates this problem by a crosshead between the connecting rod and the piston rod, this allows for a seal to be placed around the piston rod, as you can see in figure 1. Another process which degrades t he oil in a conventional gas engine is the oil’s expos ure to the high combustion heat. Many engine model s use the oil as a heat sink to reduce the operating temperature of vital engine components; however, th e AJAX’s crankcase oil is not exposed to any high tem peratures. Unlike a conventional natural gas engin e (Caterpillar, Waukesha, etc) the AJAX is a two stro ke design, as you can see in figures 2-4. With thi s design all of the high pressure combustion gasses a re on the “outboard” side of the piston, meaning no high pressure gas is ever exposed to the piston rod and thereby contaminating the oil.

Finally, the flood system is used primarily in the control box for gears, and is not a major source of degradation for the oil.HOUSTON\2332921.5 Figure 1: Combustion End

Figure 2: Compression Stroke Figure 3: Power Stroke Figure 4: Scave ngingHOUSTON\2332921.5