Reciprocating Compressor Seals Partner Savings From Compressor Rod Packing Presented to 2005 EPA Star Conference - Midland June 8, 2005 Jim Rauh, Compressor Engineering Rick Loveless, Northern Natural Gas

Engine and Compressor

Discussion Points Standard packing cases Standard packing cases How packing works How packing works Impediments to proper sealing Impediments to proper sealing Packing case leaks Packing case leaks Northern Natural case histories Northern Natural case histories Low Emission Packing (LEP) Low Emission Packing (LEP) Summary/Q and A Summary/Q and A

Compressor Cylinder Cut Away

Standard Packing Case

Pressure Activates Packing

Impediments to Proper Sealing Ways packing case can leak Nose gasket (no crush) Nose gasket (no crush) Packing to rod (surface finish) Packing to rod (surface finish) Packing to cup (lapped surface) Packing to cup (lapped surface) Packing to packing (dirt/lube) Packing to packing (dirt/lube) Cup to cup (out of tolerance) Cup to cup (out of tolerance) What makes packing leak? Dirt or foreign matter (trash) Worn rod (.0015”/per inch dia.) Insufficient/too much lubrication Packing cup out of tolerance (+.002”/-.000”) Improper break-in on startup Liquids (dilutes oil) Incorrect packing installed (backward or wrong type/style)

Typical Packing Leak Paths

Leakage Rates Packing is designed to restrict leakage Packing is designed to restrict leakage Fugitive natural gas emissions result in significant loss of revenue/greenhouse gas Fugitive natural gas emissions result in significant loss of revenue/greenhouse gas Average rod leak rate is.98 to 1.86 scfm (28-53 liters/minute) based on Pipeline Research Committee findings Average rod leak rate is.98 to 1.86 scfm (28-53 liters/minute) based on Pipeline Research Committee findings

Northern Natural/CECO Historical Data on Units A/B Monitored emission units are methane leakage in liters/minute for two locations Monitored emission units are methane leakage in liters/minute for two locations Testing is still in progress, current 3 months leak rate shows zero leakage Testing is still in progress, current 3 months leak rate shows zero leakage Unit A leakage as high as 301 liters/min Unit A leakage as high as 301 liters/min Unit B leakage as high as 105 liters/min Unit B leakage as high as 105 liters/min

NNG Unit A/B Leakage Rates

NNG Packing Leakage Economic Replacement Point Approximate packing replacement cost is $3000 per compressor rod (parts/labor) Approximate packing replacement cost is $3000 per compressor rod (parts/labor) Assuming gas at $5/MCF: 1CFM=28.316L Assuming gas at $5/MCF: 1CFM=28.316L –50 liters per min/28.316=1.766 scfm –1.766 x 1440min/day=2543 scf per day –2543/1000=2.543 MCF –2.543 x 365 days= 928MCF per year –928 x $5MCF=$4640 per year leakage

Here Is the Solution Low emission packing (LEP) overcomes low pressure to prevent leakage. Low emission packing (LEP) overcomes low pressure to prevent leakage. The side load eliminates clearance and maintains positive seal on cup face. The side load eliminates clearance and maintains positive seal on cup face. LEP is a static seal, not a dynamic seal. No pressure is required to activate the packing. LEP is a static seal, not a dynamic seal. No pressure is required to activate the packing. This design works in existing packing case with limited to no modifications required. This design works in existing packing case with limited to no modifications required.

LEP Packing Configuration

Orientation in Cup

Reasons to Use LEP Reasons to Use LEP Upgrade is very inexpensive. Upgrade is very inexpensive. Significant cost savings and reduction of greenhouse gas are major benefit. Significant cost savings and reduction of greenhouse gas are major benefit. Refining, petrochemical and air separation plants have used this design for many years to minimize fugitive emissions. Refining, petrochemical and air separation plants have used this design for many years to minimize fugitive emissions. Should the natural gas industry follow suit? Should the natural gas industry follow suit?

What’s in Your Packing Case? Consult with operations to verify your current packing case configuration. Consult with operations to verify your current packing case configuration. What are the current leak rates? What are the current leak rates? Typical LEP conversion is around $125 and with gas at $6 MSCF, packing case leakage should be identified and fixed. Typical LEP conversion is around $125 and with gas at $6 MSCF, packing case leakage should be identified and fixed. Monitoring emissions reduces greenhouse gas release. Monitoring emissions reduces greenhouse gas release.

Reduce Fugitive Emissions

Summary Packing is a dynamic seal designed to restrict leakage. Packing is a dynamic seal designed to restrict leakage. Verify your current leakage rate. Verify your current leakage rate. Low Emission Packing (LEP) is an inexpensive conversion to reduce fugitive emissions. Low Emission Packing (LEP) is an inexpensive conversion to reduce fugitive emissions.

Questions? Thank you!