The increased demand and cost of natural gas coupled with ever tightening exhaustemission standards presents a challenge to those who must extract the most powerfrom their engines while using less fuel and staying within exhaust emission regula-tions. One company helping meet these challenges with its ECV5 emissions controlvalve and VM-350 mixing venturi is San Diego, California, U.S.A.-based ContinentalControls Corporation (CCC).

The ECV5 is a computerized valve designed to precisely control the pressure of thefuel delivered to the mixing venturi or carburetor mixing bowl. As part of its package,the ECV5 installation kit typically includes a zirconium oxide O2 sensor, two type Kthermocouples and a computerized monitoring and display unit. When the ECV 5and mixing venturi are used in conjunction with a three-way catalytic converter,engine emissions are reduced to a minimum.

The new VM-350 mixing venturi is designed to replace carburetors or mixing bowlsand precisely mix the air and fuel admitted to the engine. This venturi also has anoption to measure air flow to the engine. When used as a package with the ECV5, theVM-350 or VM-350 XL replaces the carburetor and pressure regulator on both rich-burn and lean-burn turbocharged or naturally aspirated, gaseous-fueled reciprocatingengines with outputs of up to about 3000 kW depending on the fuel supply pressure.

“The ECV5 and VM-350 system bases its control on fuel pressure and then wetake feedback from the O2 sensor to readjust the pressure set-point,” said RickFisher, of Continental Controls Corporation. “This is a more efficient approach thanthe typical bypass or restrictor type valve systems.”

According to Fisher, with a bypass control system, the engine is set up to run leaninitially, with fuel added as needed based on engine load. A restrictor valve system is setup just the opposite, and relies on a pressure regulator to control fuel pressure to the

engine, then a butterfly or stepper motoris used to restrict fuel to the engine basedon its load requirements. Both of thesesystems offer limited performance capa-bility because they can only add orrestrict fuel over a narrow range.

“The beauty of our system is that it isa ‘full authority’ fuel valve that can con-trol all of the fuel to the engine all of thetime,” said Fisher. “The ECV5 can beused in conjunction with a carburetor,but to control the fuel in that set-up, theECV5 has to chase the profile up anddown a wider scale. It can do it, but it ismore difficult. In addition, a carburetoris not the most efficient method to mixair and fuel.”

These obstacles are eliminated whenthe VM-350 mixing venturi is usedwith the ECV5. “The venturi is the ulti-mate in air/fuel control when used withthe ECV5 because it keeps the fuelpressure profile the same throughoutthe whole engine operation range,” saidFisher. “The fuel pressure to the engineis the same regardless of engine load sowe are able to set up the pressure of theunit to be right around zero. There isnothing to change; the pressure isaltered within the venturi based on itsdesign to counteract the pressure.

“The only time the fuel pressure to theventuri has to change — this is handledby the ECV5 — is if the Btu value of thefuel or the ambient air temperaturechanges. However, these are subtlechanges by comparison to a load changeon a carbureted application.

“Using the venturi and the ECV5together really allows us to take care of

Air/Fuel Control Key to EnginePerformanceContinental Controls’ products combine to increase output and fuel efficiency while holding the line on exhaust emissions

58 May 2005 Diesel & Gas Turbine Worldwide

SERVICE & UPGRADES BY MIKE MERCER

Continental Control Corporation converted the fuel control sys-

tems on two Enterprise GSG-8 engines at the Coalinga, California,

U.S.A., crude oil pipeline station owned by ConocoPhillips Pipe

Line Co.

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Diesel & Gas Turbine Worldwide May 2005 59

SERVICE & UPGRADES

almost any application,” continuedFisher. “The venturi could be used withother air/fuel ratio controllers in appli-cations where just the carburetor isreplaced by the venturi. However, theultimate package is the ECV5 and theVM-350 venturi used together.”

Just one company to successfullyadapt the ECV5 and VM-350 as a pack-age is ConocoPhillips Pipe Line Co.with five crude oil pipeline stations thathave been, or are in the process ofbeing upgraded, to solve serious engineperformance issues. One station, locat-ed in Coalinga, California, was a specialcase. It includes three naturally aspirat-ed, spark-ignited Enterprise GSG-8engines rated 597 kW at 525 r/min.

Each inline, eight-cylinder engine dri-ves a Sulzer Bingham two-stage pumpthrough a Lufkin gearbox. The pumpsnow have a maximum flow rate of 120000 barrels of oil per day and currentlyaverage about 96 000 barrels per day.Two of these engines have been convert-ed to include an ECV5 with an O2 sen-sor in the exhaust stream and ECVI dis-play along with two ContinentalControls’ VM-350 venturi.

“The reason we switched to theContinental Controls fuel control set-upwas to get the engines to run correctlyand to get the most horsepower out ofthem possible,” said Keith Blumert ofConocoPhilips Pipe Line. “In the past,we ran the engines and pumps at a lowerpipeline throughput. However, with theincreased demand for refining capacity,we needed to increase the flow on thatpipeline. When we tried to step it up,the Enterprise engines detonated, espe-cially in the hot summer months, andwe were unable to get full power out of

them. That was when we went lookingfor a solution.”

Blumert contacted Continental Con-trols Corporation, a company he hadpreviously worked with on similar appli-cations in similar circumstances.

Ross Fisher of Continental ControlsCorp. visited the Coalinga facility andconfirmed that the engines could notcarry more than about 60% of their ratedload because of detonation. The evalua-tion showed that each engine’s originalintake manifolds had been modified toadd a second carburetor — most likelyto improve performance. The modifica-tion split the single intake manifold intotwo — one manifold and carburetor fedthe first four cylinders while the secondfed the other four cylinders.

“When the air-fuel flow through theintake manifolds was analyzed fromthe firing order data, the problembecame obvious,” said Fisher. “With-out a split in the manifold, there wouldalways be two cylinders drawing in anair/fuel mixture. However, when themanifold was split, the second mani-fold has no cylinders drawing fuel inthe 90 to 180 degree crank angle range,the result is that the fuel-air pressure inone manifold increases to near atmos-pheric as the other manifold fills, per-mitting a larger charge of fuel to beadmitted into cylinder number 7 whenits intake valve opens. The same thinghappens later in the other manifoldwhere cylinder number 2 gets an exces-sive air-fuel charge. This causes thesecylinders to detonate first, preventingfurther loading of the other cylinders.”

To compound the problem, Fisherdetermined that the diameter of theintake manifold is actually less than the

piston diameter and thus, the manifoldhad no storage capacity for the air/fuelmixture. In addition, the pressure inthe manifold varies with flow since thethrottle plate position does not vary ona cylinder-to-cylinder basis.

The solution was determined toinclude two parts. A single larger diam-eter intake manifold was needed andthe Continental Controls ECV5 emis-sions control valve and twin VM-350mixing venturi were to be installed.

The venturi each measures the volu-metric air-flow and provides the throatpressure of the venturi at an externalport. The throat pressures of the venturiare compared to balance the volumetricair flow when adjusting the throttleplates. A second measuring port on theventuri is the pressure of the fuel inannulus around the venturi. The pres-sures in the ports of the venturi are com-pared and balanced by adjusting the but-terfly valves in the gas inlet port of theventuri.

Other modifications to the engineswere the replacement of the oil bathintake air filters with dry panel-type fil-ter elements from Spitzer, Altronic CPU2000 ignition systems and Hilliard vac-uum demisters for crankcase vapors.Additional improvements to the enginesrecently included cartridge style spin-onoil filters and the addition of Inconelmetal exhaust valves. The valve materialchange allows the engines to run harderat higher temperatures. According toBlumert, the last step to improve engineefficiencies is to switch to syntheticlubricants.

“We basically wanted to get rid of thecarburetors to remove restriction fromthe intake system to get more air throughthe engines and get more horsepowerout of them,” said Blumert. “In the proc-ess we eliminated the detonation prob-lem and improved the fuel efficiency.The cost to upgrade these engines wasless than the cost to replace them. Theseengines still run seven days per week,365 days per year.

“We continue to operate under EPArestrictions for NOx and CO,” saidBlumert. “We could meet these restric-tions before (but only at reduced

Picture of an Enter-

prise engine before

conversion at the

Coalinga, California

station.

continued on page 60

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60 May 2005 Diesel & Gas Turbine Worldwide

SERVICE & UPGRADES

loads), and we are meeting them nowwith the switch to CCC products.”

There are seven more Enterpriseengines to be converted, according toBlumert, two at the Santa Margarita sta-tion near San Luis Obispo, California,two at the Torrey station near SantaPaula, California, and three at what hereferred to as the Patterson station inCalifornia.

ConocoPhillips Pipe Line has also car-ried out conversions of three Waukesha7042 engines located at its Junctionpumping station. These Vee 12-cylinder,

naturally aspirated, natural gas-fueledengines are rated 858 kW at 1200 r/minand like Coalinga are also fueled by util-ity supplied gas. The Waukesha enginesdrive three-stage pumps through Lufkingearboxes.

These engines use a single VM-350venturi, single ECV5 control and singleO2 feedback system for each cylinderbank of the V-12 engines. The air filterswere also upgraded to Spitzer dry panelunits.

“Although these engines did not havea detonation problem, we upgraded

them for similar reasons,” said Blumert.“With the Continental Controls’ sys-tems, we were able to eliminate the car-buretors to get more usable horsepowerout of the engines in the summer heat.That was the main reason. However, it isalso good from a consistency standpointfor service.”

According to Blumert, since theseengines were installed over 15 years ago,they have been well maintained and havereceived the Waukesha Extender up-grade packages over the years that includ-ed such components as updated cylinderliners and pistons, as well as bearings, fil-tration and lubrication upgrades alongwith the Inconel exhaust valves. Theseengines also use Altronic ignition sys-tems, Hilliard vacuum demisters andJohnson Matthey catalytic converters.

All of these pump stations are contin-uously monitored and controlled re-motely from ConocoPhillips pipelinecontrol center in Ponca City, Oklahoma,U.S.A. a

SEE DIRECTLINK @

WWW.DIESELGASTURBINE.COM

ConocoPhillips Pipe Line Co.

also carried out conversions

of three Waukesha 7042 en-

gines located at its Junction

pumping station. With the

Continental Controls’ sys-

tems they were able to elim-

inate the carburetors to get

more usable horsepower

out of the engines in the

summer heat.

OIL& GAS

PRODUCTS, TECHNOLOGIES AND ACTIVITIES BY MIKE MERCERNEWS

GE Turbines in ThailandGE Energy’s oil and gas business has signed a strategic agreement with PTT Utility

Company Limited (PTTUT) of Thailand for the supply of equipment and services.PTTUT is an affiliate of PTT, established to provide utilities to PTT’s PetrochemicalGroup. PTT is Thailand’s fully integrated energy company and has the largest mar-ket capitalization of all energy companies listed on the stock exchange in Thailand.

Under the new agreement, PTTUT and other affiliated companies of the PTTGroup will purchase eight GE gas turbine-generator packages within the next fouryears, for a total value of more than US$80 million. The first gas turbine packageawarded under the agreement was purchased by National Petrochemical (NPC), anaffiliated petrochemical company of PTT. A

TEMA Receives PrivateEquity Investment

Actis, a London-based private equi-ty investor in emerging markets, hasspent US$12 million to secure a stakein TEMA India Ltd., the heat exchang-er manufacturer. TEMA India special-izes in designing and fabricating shelland tube heat exchangers for the oiland gas, energy and chemical indus-tries. It also makes high-pressure heatexchangers and has won contractswith EPC contractors for the oil andgas industry including Bechtel, Fluor,Technip, Uhde and Jacobs.

TEMA, has achieved revenues ofUS$20 million in the year endingMarch 2005 and the investment willhelp the company to establish a newfacility, allowing it to fulfill larger sizeorders and improve manufacturingprocesses, enhancing margins andbuilding overseas sales, according to thecompany. A

MHI and Solar Sign AgreementMitsubishi Heavy Industries Ltd. (MHI) has signed a cooperative agreement

with Solar Turbines Incorporated relating to centrifugal compressors. Under theagreement, MHI will supply its MAC (Mitsubishi Advanced Compressor) cen-trifugal compressors to Solar Turbines and Solar Turbines will offer packagescoupling the compressors with its own gas turbines. Initially, the agreement is toapply to MHI’s standard-design MAC compressors that match to Solar Turbines’gas turbines with power outputs ranging between 8 and 15 MW (models Mars90, Mars 100 and Titan 130). Mitsubishi Corporation, acting in the role of trad-ing company, will cooperate in the application and sales of these products. A

WW506&501.qxp 4/13/05 1:34 PM Page 3

SERVICE & UPGRADES

loads), and we are meeting them nowwith the switch to CCC products.”

There are seven more Enterpriseengines to be converted, according toBlumert, two at the Santa Margarita sta-tion near San Luis Obispo, California,two at the Torrey station near SantaPaula, California, and three at what hereferred to as the Patterson station inCalifornia.

ConocoPhillips Pipe Line has also car-ried out conversions of three Waukesha7042 engines located at its Junctionpumping station. These Vee 12-cylinder,

naturally aspirated, natural gas-fueledengines are rated 858 kW at 1200 r/minand like Coalinga are also fueled by util-ity supplied gas. The Waukesha enginesdrive three-stage pumps through Lufkingearboxes.

These engines use a single VM-350venturi, single ECV5 control and singleO2 feedback system for each cylinderbank of the V-12 engines. The air filterswere also upgraded to Spitzer dry panelunits.

“Although these engines did not havea detonation problem, we upgraded

them for similar reasons,” said Blumert.“With the Continental Controls’ sys-tems, we were able to eliminate the car-buretors to get more usable horsepowerout of the engines in the summer heat.That was the main reason. However, it isalso good from a consistency standpointfor service.”

According to Blumert, since theseengines were installed over 15 years ago,they have been well maintained and havereceived the Waukesha Extender up-grade packages over the years that includ-ed such components as updated cylinderliners and pistons, as well as bearings, fil-tration and lubrication upgrades alongwith the Inconel exhaust valves. Theseengines also use Altronic ignition sys-tems, Hilliard vacuum demisters andJohnson Matthey catalytic converters.

All of these pump stations are contin-uously monitored and controlled re-motely from ConocoPhillips pipelinecontrol center in Ponca City, Oklahoma,U.S.A. a

SEE DIRECTLINK @

WWW.DIESELGASTURBINE.COM

ConocoPhillips Pipe Line Co.

also carried out conversions

of three Waukesha 7042 en-

gines located at its Junction

pumping station. With the

Continental Controls’ sys-

tems they were able to elim-

inate the carburetors to get

more usable horsepower

out of the engines in the

summer heat.

60 May 2005 Diesel & Gas Turbine Worldwide

OIL& GAS

PRODUCTS, TECHNOLOGIES AND ACTIVITIES BY MIKE MERCERNEWS

GE Turbines in ThailandGE Energy’s oil and gas business has signed a strategic agreement with PTT Utility

Company Limited (PTTUT) of Thailand for the supply of equipment and services.PTTUT is an affiliate of PTT, established to provide utilities to PTT’s PetrochemicalGroup. PTT is Thailand’s fully integrated energy company and has the largest mar-ket capitalization of all energy companies listed on the stock exchange in Thailand.

Under the new agreement, PTTUT and other affiliated companies of the PTTGroup will purchase eight GE gas turbine-generator packages within the next fouryears, for a total value of more than US$80 million. The first gas turbine packageawarded under the agreement was purchased by National Petrochemical (NPC), anaffiliated petrochemical company of PTT. A

TEMA Receives PrivateEquity Investment

Actis, a London-based private equi-ty investor in emerging markets, hasspent US$12 million to secure a stakein TEMA India Ltd., the heat exchang-er manufacturer. TEMA India special-izes in designing and fabricating shelland tube heat exchangers for the oiland gas, energy and chemical indus-tries. It also makes high-pressure heatexchangers and has won contractswith EPC contractors for the oil andgas industry including Bechtel, Fluor,Technip, Uhde and Jacobs.

TEMA, has achieved revenues ofUS$20 million in the year endingMarch 2005 and the investment willhelp the company to establish a newfacility, allowing it to fulfill larger sizeorders and improve manufacturingprocesses, enhancing margins andbuilding overseas sales, according to thecompany. A

MHI and Solar Sign AgreementMitsubishi Heavy Industries Ltd. (MHI) has signed a cooperative agreement

with Solar Turbines Incorporated relating to centrifugal compressors. Under theagreement, MHI will supply its MAC (Mitsubishi Advanced Compressor) cen-trifugal compressors to Solar Turbines and Solar Turbines will offer packagescoupling the compressors with its own gas turbines. Initially, the agreement is toapply to MHI’s standard-design MAC compressors that match to Solar Turbines’gas turbines with power outputs ranging between 8 and 15 MW (models Mars90, Mars 100 and Titan 130). Mitsubishi Corporation, acting in the role of trad-ing company, will cooperate in the application and sales of these products. A

WW506&501.qxp 4/13/05 1:34 PM Page 4