2015

Reducing Vent Gas Emissions with

New Rod Sealing Solutions for

Reciprocating Compressors

Jack Schwaller

Hoerbiger Corporation of America

2015

The HOERBIGER Group headquartered in Zug, Switzerland,

is a global leader in the fields of compression technology,

drive technology, and hydraulic systems.

• Over 7,000 employees worldwide.

• Over 1 billion euros sales.

• Innovated solutions for compressors, industrial engines and turbines.

2015

• Performance of Rod Packing in a

Reciprocating Gas Compressor

• GHG Regulations

• Sealing Solutions

2015

We see how the inlet gas enters the

cylinder, is compressed and is then

discharged downstream.

The contained compressed gas will seek

atmosphere by migrating down the

moving rod that powers the piston.

The Rod Packing Assembly will prevent

this escape.

Here is a cutaway of a typical

reciprocating compressor cylinder.

2015A close-up of this assembly

� a series of individual pressure

activated seals to reduce cylinder

pressure to atmosphere

� each seal must float to allow the

rod and piston to move

independently.

� this will cause a small amount of

leakage with each compression

stroke.

2015

Acceptable leakage of

12 cfh(cubic feet per hour per cyl.) =

*1720 cfday(cubic feet per day per

compressor

.033 tonnes CH4 per day

<12 tpy(year)

*6 cylinder compressor

2015Failed Rod packing might see ten

times that leakage.

.33 tonnes CH4 per day

<120 tpyear per compressor

Potential leak paths:

1. Around the gasket or between

gland components

2. Around worn Seals and inner

gland faces

3. Or down the worn Rod

2015The EPA recognizes Recips as “a major source”

Oil and Natural Gas Sector: Emission Standards for New and Modified

Sources 40 CFR Part 60 -- includes both (GHG)Methane and VOC gases

Calls for Recip compressors to

1. change-out seals every 36 month(26000 hours) or less

2. routine leakage checks

3. annual reporting of change-outs.

Carbon offsets required by some states.

Voluntary efforts to reduce GHG losses

2015Compliance with Federal or Local Regulations

Many sites will have to upgrade their seals and maintenance practices.

This starts with a survey and gap analysis for each affected site.

� Rod Packing assembly to achieve the 3 years, requires quality seal designs

� Case assembly rebuild and test program evaluated.

� Evaluate cylinder rebuild and Rod Packing installation procedures.

� Seal vent leakage measure procedure established

� Reporting process upgraded.

2015Quality Rod Seal Performance BCD Seal Ring with an innovative geometry to improve rod contact

� reduced loading/frictional heat = achieve the 36 month life

� very low leakage < 12scfh

� simple and robust one-ring design

� easy to install

2015Quality Rod Seal Performance BCD Seal Ring Hundreds of applications:

� Natural gas applications wellhead to CNG to 2500PSI

� Process Refinery, Air Reduction, Refrigeration

� CO2 Injection

Flash-Gas Compressor

2015Continuous sealing - SBS (Stand-by Seal) Compressor is shutdown and pressurized will still leak!

� Minimize the number blow-downs

� Reduce leakage to near zero (in standby)

� Reduce gas loss via leaking yard valves

special sealing cartridge added to the seal assembly

activated hydraulically.

SBS and the XperSEAL for continuous sealing to

be available early next year

2015Certified replacement or new Seal Assemblies

for 36 month replacement cycle

� reconditioned back to ‘as new’ condition

� tested and certified to zero leakage

2015Best practices installation

Proper installation of seal assembly and alignment for minimal

rod and piston “runout”

1. New gasket contacting a renewed inner cylinder surface

2. Proper torqueing of bolts

3. Old snoop/bubble test vs OGI Optical Gas Imaging or Parts per Million detectors.

2015

Summary

New low leakage seal performance requires new Technologies and

methods

• BCD High performance seals are part of the solution

• SBS to offer ‘near zero’ stand-by sealing

• Certified zero leakage cases

• Special installation care to pass new field tests for leakage.