The World’s Best Compressors™

For Industrial Refrigeration

450XL® CompressorFor Industrial Refrigeration

While retaining all of the features that are exclusive to Vilter compressors, we’ve made several design improvements:

• Piston

• Connecting road and bearing insert

• Crankshaft

• Safety head

• Capacity reduction system

Even though we’ve made these specific changes, we’ve retained all of the exclusive Vilter features, including provisions for fast and easy servicing with components that are easy to access.

The 450XL can operate with ammonia, halocarbon and even some hydrocarbon refrigerants. It works in extreme applications with up to a 250# pressure differential. It can be belt-driven up to 300 bhp or direct driven all the way up to 375 bhp. And it can run at high compression ratios all the way up to 12:1 with certain halocarbon refrigerants.

450XL Cross Section

Spring Loaded Safety HeadsProtect against liquid slugging by relieving internal cylinder pressure if cylinders are subjected to an incompressible fluid.

Piston and Connecting RodThe unique design of the piston and connecting rod assembly allows for movement only between the connecting rod bushing and piston pin, while providing positive lubrication throughout the entire compression cycle.

Double Tapered Roller BearingsEnergy-efficient roller bearings enable the compressor to be used for high suction pressure applications as well as high belt-drive horsepower requirements.

Tri-Micro® Oil FilterRemoves 95% of contaminants as small as 3 microns in size. Allows full flow of oil at all times, resulting in reduced wear on compressor components. Combines extreme filtering capacity with the convenience of a throw-away recharge element. Filter is enclosed in a seamless drawn carbon steel shell with cast iron cover, and is equipped with a means for determining pressure drop across the filter.

Suction and Discharge PortingMaximum suction and discharge porting through the compressor achieves minimum pressure drop with valve plates that are made to exacting Vilter material and manufacturing requirements for long-term service.

The versatile VMC 450XL is now even better!

Far-Reaching Applications

Compression and Oil RingsThe 450XL piston ring set consists of three compression rings and a single, special oil scraper ring for keeping oil consumption to an absolute minimum.

Heavy-Duty Crankshaft*An over-sized crankshaft pin diameter provides years of rugged, dependable duty, while the larger bearing surface allows for higher pressure differential capabilities.

Connecting Rod Bearings*Vilter’s unique oil circuit drilling arrangement ensures proper hydrodynamic lubrication of insert bearings throughout the entire compression process. Rod bearings are specially designed to supply lubrication to the piston pin bushing at all times.

Double Bellows Shaft SealThe 450XL shaft seal, designed to specific Vilter specifications, is manufactured from materials strictly used for industrial refrigeration applications. Seal unit assembly consists of two opposed seals – one sealing from the atmosphere and the other from the crankcase. Mating seal surfaces are lubricated and cooled by circulated oil.

Single Casting FrameThe single casting frame incorporates suction and discharge manifolds plus bearing supports. It’s cast to exacting tolerances from a high grade of cast iron to withstand extreme changes in heat and pressure. The castings are notably free from porosity and internal strains, and display excellent wearing qualities.

*Patented Design

Even with all these built-in features, you’ll still find the 450XL to be extremely cost-efficient. This compressor has a whopping 50-cfm/cylinder displacement while running at 1200 RPM. And the high isentropic efficiency of the 450XL means its bhp/ton is second to none when compared to other compression systems on the market today.

The 450XL can be installed almost anywhere, even on an upper floor if necessary, since vibration is kept to a minimum. Noise level is low too, due to the use of quick-acting, precise ring plate suction and discharge valves.

The 450XL is so versatile it can handle almost any refrigeration system conditions. Up to 350 psig maximum discharge, and up to 150 psig maximum suction with a maximum 250 psig pressure differential. At different compression ratios, too, from 8:1 for ammonia to 12:1 for R-22. In V-belt configurations all the way up to 300 bhp, or direct drive setups up to 375 bhp. And it’s usable for both 50 cycle and 60 cycle applications up to 1200 RPM.

The graph (Figure 2) on the next page depicts the broad range of applications suitable for the 450XL.

100(75)

80(60)

60(45)

40(30)

20(15)

(633)

(563)

(492)

(422)

(352)

(281)

(211)

(141)

(70)

°F°C

S A T U R A T E D S U C T IO N T E M P E R A T U R E °F (°C )

CA

PAC

ITY

To

ns (k

WR)

( -18) (-12) (-7 ) (-1 )(-40) (-34) (4) (10) (16)(-29) (-23)

H igh S tage C apacities454X L

0

20

40

60

80

100

120

140

160

180

-40 -30 -20 -10 0 10 20 30 40 50 60

R -717

R -717

R -22

R -290

R -290

R -134a

R -404a/ R -507 R -22

R -404a/ R -507

R -134a

Tons (kWR) BHP (kW)

BH

P (k

W)

Figure 1 High-Stage Capacities

M in im um A llow ab leS uction P ressure R P M 452X L-458X L 4512X L-4516X L

= 24" V acuum 1,200 200 300(≈ -11 .8 P S IG / 2 .9 P S IA ) 1 ,130 200 300

1,000 150 250

M axim um M otor H P (V -B e lt D rive)

-50

0

50

100

150

200

250

300

350

400

-12 0 12 24 36 48 60 72 84 96 108 120 132 144

S U C T IO N P R E S S U R E (P S IG )

D IS C H AR G E P R E S S U R E

(P S IG )

M A X 14:1 (R -404a & R -507)M A X 12 :1 (R -22)M A X 10 :1 (R -134a & R -290)M A X 8 :1 (R -717)

Figure 2 Broad Applications

4516XL Belt Drive Recip Pak with VILTech Micro-Controller

Nominal High-Stage CapacitiesWith its 4-1/2” x 4-1/2” bore and stroke, the 450XL provides up to30% more capacity than similar size compressor units, all while maintaining a favorable bhp/ton ratio.

Nominal high-stage ratings for the 450XL are shown in Figure 1below.

The following conditions were used in establishingthese ratings:• 1200 RPM• Saturated suction.• No subcooling.• No belt losses.• All ratings are based on 95°F condensing temperature.• Ratings are based on a 4-cylinder 450XL (454XL). Fortonnage and approximate bhp fi gures of other 450XL models, use a direct proportion to the number of cylinders of the 454XL. For example, use a 3.0 factor for determining the 12-cylinder 450XL tons and approximate bhp fi gures.

Complete detailed ratings for all 450XL high-stage models, plusratings for 450XL booster compressors, special high suctionpressure compressors, and even integral two-stage compressors,are available for all major refrigerants either from the Vilter homeoffi ce, your Vilter District Sales Offi ce, or from an Authorized Vilter Distributor.

Time-Honored Features

Vilter’s attention to detail shows wherever you look.

Over a century of experience in refrigeration compressor design goes into each and every part that comprises the 450XL.

We’ve designed our component parts to work together, not just fi t together. That’s why Vilter guarantees that all Genuine Vilter Parts will match your Vilter compressor dimensionally, metallurgically and thermally for optimum compressor performance.

With Genuine Vilter Parts, you can be assured of getting the engineering design and special construction features that only Vilter can offer. Consider some of the special manufacturing steps that Vilter parts go through:

• Select surfaces are shot-peened for added strength

• Mating faces are lapped for greater compressor efficiency

• Many parts are ultrasonically inspected for maximum reliability

• The steels used are of special alloys for durable performance

• Exacting tolerances are measured in light bands rather than in thousandths of inches

The Vilter 450XL Full Two-Year Warranty

The 450XL compressor is fully warranted against defects of materials and workmanship under normal use and service, for a period of two years from date of shipment regardless of startup date. For example, if startup occurs one month from shipping date, the customer will have a full twenty-three (23) months of warranty coverage after startup.

Genuine Vilter Parts

When you need parts for your 450XL compressor – whether for repair work or scheduled maintenance – make sure you specify Genuine Vilter Parts.

Look for the Genuine Vilter Part mark that is either etched or stamped directly on all major Vilter parts. It’s your assurance of Vilter warranty protection. In some cases, where a replacement part does not lend itself to stamping or etching, a blue tag will identify the part as a Genuine Vilter Part. Vilter replacement parts (except those too big to box) are shipped in boxes that have the Genuine Vilter Part mark right on the box itself.

Don’t be misled by look-alike, no-name imitations of Vilter compressor parts that carry vague warranties. Cheap parts can become an expensive mistake. Make sure you insist on using only Genuine Vilter Parts, and that you contact an Authorized Vilter Distributor (or Vilter direct) for all your 450XL parts requirements

• A shrink-fit wrist pin is used to increase bearing load capacity.

• Hardened steel wrist pins are ground and polished to size.

• Three cast iron compression rings and one oil ring provide a positive seal while wiping oil back to the crankcase.

• Replaceable insert bearing improves lubrication and load carrying capacity.

• Forged connecting rods back the precision-made, steel-backed Babbitt insert bearing.

• Grooved wrist pin bushings are fed with pressurized lubricating oil.

• Designed with a bigger crankpin diameter for greater load bearing and bearing surface.

• All crankshafts are statically and dynamically balanced for reduced vibration.

• Precision drilled crankshaft ensures proper lubrication through the compression cycle.

• The 6, 8, 12, and 16-cylinder crankshafts are shot-peened for greater strength.

• Spring loaded safety heads provide protection against liquid slugging.

• The suction and discharge porting improve compressor efficiency.

• A piston operated unloading mechanism lifts the suction valve plate to unload the cylinders for reduced capacity or unloaded starts.

• Simplified unloading piston allows easy removal for seal servicing.

Piston, Pin and Ring Assembly Ductile Iron Crankshaft Spring Loaded Safety Heads Capacity Reduction SystemConnecting Rod, Bearing and Bushing

General SpecificationsThe complete line of 450XL compressors is comprised of six models ranging from a nominal 25-ton 2-cylinder machine all the way to the high end of the scale – a nominal 200-ton 16-cylinder model. In-between are the 4, 6, 8 and 12-cylinder mid-size units. All 450XL compressors run at a maximum of 1200 RPM, and all are provided with built-in capacity reduction steps for economical operation at reduced loads. V-belt and direct-connected motor operation are also available throughout the entire range of 450XL models.

We’ve tried to make every inch count in designing the 450XL to fit into even the tightest space requirements. The 450XL is a machine that provides 50 cfm/cylinder, giving you maximum capacity in a minimum amount of space.

There’s sure to be a 450XL model that’s a perfect match to your refrigeration application.

Engineering SpecificationsThe compressor shall have double shaft seal; double tapered, roller main shaft bearings;

Tri-Micro® oil filter and oil strainer that removes 95% of contaminants as small as 3 microns in size; dynamically and statically balanced heavy duty crankshaft of ductile iron, also shot-peened on 6, 8, 12 and 16-cylinder models; spring safety heads; die-forged, steel connecting rods with replaceable bearing halves; aluminum type heat treated pistons with three compression rings and one oil ring; piston operated suction valve lifters to unload the compressor for starting and to provide capacity control. The piston and connecting rods shall be assembled with a shrink-fit wrist pin for higher load carrying capabilities and superior wearing qualities.

The compressor(s) shall be equipped with the additional following standard equipment: crankcase oil thermometer and heater; oil filter pressure gauge with manual 3-way valve; oil failure switch; high and low pressure cutout; capacity control switches and unloader solenoid valves for ______ steps of capacity reduction; water or refrigerant cooled oil cooler; suction, discharge, and oil pressure gauges complete with Stedy-Mounts® and shut-off valves; ___ (water or refrigerant) cooled cylinder covers.

Compressor(s) shall come complete with structural steel base, and be driven by a ___ HP, __________ RPM, _____ volt, _____ phase _____ cycle motor with direct coupling and coupling guard, or V-belt drive with flywheel, belts and motor sheave for _____ RPM. Compressor(s) shall have a capacity of not less than ____ tons when operating at _____ °F (psig) suction temperature (pressure) and _____ psig (°F) condensing pressure (temperature). Compressors are to be manufactured by Vilter Manufacturing Corporation, Cudahy, Wisconsin, or equal as approved.

4512XL Direct Drive Recip Pak with Superseparator and VILTech Micro-Controller

General DimensionsITEM 452XL 454XL 456XL 458XL 4512XL 4516XL

Number of Cylinders 2 4 6 8 12 16

Maximum RPM 1200 1200 1200 1200 1200 1200

Bore & Stroke - In. (mm)4½x4½

(114x114)4½x4½

(114x114)4½x4½

(114x114)4½x4½

(114x114)4½x4½

(114x114)4½x4½

(114x114)

CFM @ Maximum RPM (m3/hr) 99.4(169) 199(338 298(507) 398(676) 597(1014) 796(1352)

Tons(Kcal/hr x 103) Refrigeration @ 95°F Condensing

R-717 (10°F) 24(73) 49(148) 73(221) 97(293) 146(442) 195(590)

R-22 (20°F) 29(88) 59(178) 88(26) 117(354) 176(532) 235(711)

R-290 (0°F) 16(48) 31(94) 47(142) 62(187) 94(284) 125(378)

Suction Connection - Inches (mm) 2½(64) 3(76) 4(102) 4(102) 5(127) 6(152)

Discharge Connection - Inches (mm) 2(51) 2½(64) 3(76) 3(76) Two 3(76) Two 3(76)

Unit Weight Less Motor - Lbs. (Kg.) 1900(862) 2700(1225) 3100(1406) 3400(1542) 5300(2404) 5800(2630)

Oil Charge - Gallons (Liters) 5(19) 7(27) 7(27) 7(27) 14(53) 14(53)

Standard Steps of Unloading (%) 0 50 33/66 24/50 33/66 25/50

Option 1 Steps of Unloading (%) 50 25/50/75 - 25/50/75 - 25/50/75

Option 2 Steps of Unloading (%) 100 50/100 33/66/100 25/50/75/100 33/66/100 25/50/75/100

Maximum Discharge Temp. - °F (°C) 300(149) 300(149) 300(149) 300(149) 300(149) 300(149)

Crankcase Oil Temp. Range - °F (°C)110-130(43-54)

110-130(43-54)

110-130(43-54)

110-130(43-54)

110-130(43-54)

110-130(43-54)

Vilter reserves the right to make changes in design and specifi cations without notice.

2 & 4 Cylinder Units 6 & 8 Cylinder Units 12 & 16 Cylinder Units

General Dimensions – The dimensions shown above are approximate, and should not be used for construction. Vilter issues certified prints for construction purposes. These dimensions are provided in inches, and are followed in parenthesis by millimeters – in. (mm) Space needed to remove flywheel – 7” (178mm). Space needed to remove crankshaft, from wall to centerline of compressor – 42” (1067mm) for 2-8 cylinder models, and 84” (2134mm) for 12-16 cylinder models.

Cyls. A B C D E12 83”(2108) 79-1/4”(2013) 58-1/2”(1486) 20”(508) 59-5/8”(1514)16 83”(2108) 79-1/4”(2013) 62-1/4”(1581) 20”(508) 59-5/8”(1514)

Cyls. A B C D E6 76”(1930) 55-1/2”(1410) 40-38”(1026) 20”(508) 34-18”(867)8 76”(1930) 56:(1422) 39”(991) 20”(508) 34-34”(883)

Cyls. A B C D E12 83”(2108) 79-1/4”(2013) 58-1/2”(1486) 20”(508) 59-5/8”(1514)16 83”(2108) 79-1/4”(2013) 62-1/4”(1581) 20”(508) 59-5/8”(1514)

Cyls. A B C D E2 78-3/4”(2000) 41”(1041) 49-9/16”(1259) 20”(508) 29-1/8”(740)4 86-3/4”(2203) 41-12”(1054) 51-9/16”(1310) 20”(508) 31-9/16”(802)

Cyls. A B C D E12 92-3/4”(2356) 42-1/4”(1073) 40-3/8”(1026) 20”(508) 34-1/8”(867)16 95-1/4”(2419) 44-7/8”(1140) 39”(991) 20”(508) 34-3/4”(883)

Cyls. A B C D E12 128-1/4”(3258) 50-3/8”(1280) 60”(1524) 21-1/2”(546) 59-5/8”(1514)16 128-1/4”(3258) 50-3/8”(1280) 63-5/8”(1616) 21-1/2”(546) 59-5/8”(1514)

Cyls. A B C D E2 69”(1753) 48-7/8:(1241) 49-7/16”(1256) 20”(508) 29-1/8”(740)4 74”(1880) 50-1/32”(1271) 51-7/16”(1310) 20”(508) 31-9/16”(802)

Cyls. A B C D E6 76”(1930) 56-1/2”(1435) 40-3/8*(1026) 20”(508) 34-1/8”(867)8 76”(1930) 57”(1448) 39”(991) 20”(508) 34-3/4”(883)

Cyls. A B C D E12 83”(2108) 80-1/4”(2038) 57”(1448) 20”(508) 59-5/8”(1514)16 83”(2108) 80-1/4”(2038) 60-1/8”(1527) 20”(508) 59-5/8”(1514)

Cyls. A B C D E2 78-3/4”(2000) 41”(1041) 49-7/16”(1256) 20”(508) 29-1/8”(740)4 86-3/4”(2203) 41-12”(1054) 51-7/16”(1310) 20”(508) 31-9/16”(802)

Cyls. A B C D E6 93”(2369) 42-1/4”(1073) 40-3/8*(1026) 20”(508) 34-1/8”(867)8 95-3/4”(2432) 44-7/8”(1140) 39”(991) 20”(508) 34-3/4”(883)

Cyls. A B C D E12 128-3/4”(3270) 50-3/8”(1280) 58-1/2”(1486) 21-1/2”(546) 59-5/8”(1514)16 128-3/4”(3270) 50-3/8”(1280) 61-5/8”(1565) 21-1/2”(546) 59-5/8”(1514)

V-Belt Drive Ammonia

Direct Drive Ammonia

V-Belt Drive Halocarbon

Direct Drive Halocarbon

EmersonClimate.com

Vilter Manufacturing LLC5555 South Packard Ave.Cudahy, Wisconsin 53110-8904www.vilter.com

Telephone: (414) 744-0111Fax: (414) 744-3483Email: info.vilter@emerson.com

District Sales Offices & Distributors Worldwide

2010VM-42 (4/10) (Previously Vilter Bulletin No. 1004 DLC/3.5m/01-09) Emerson and Vilter are trademarks of Emerson Electric Co. or one of its affiliated companies. ©2009 Emerson Climate Technologies, Inc. All rights reserved. Printed in the USA. Vilter Manufacturing LLC reserves the right to make changes in design and specifications without notice.

Vilter reserves the right to make changes in design and specifications without notice.Emerson and Vilter are trademarks of Emerson Electric Co. or one of its affiliated companies.

©2010 Emerson Electric Co. All rights reserved. Printed in U.S.A

FeaturingtheExclusive

The VSM Vilter Single Screw compressoris a rotary, positive displacement com-pressor which incorporates a mainscrew and two gaterotors. Compressionof the gas is accomplished by theengagement of the gaterotors with thehelical grooves in the main screw. Anelectric motor imparts the rotary motionthrough a driveshaft to the compressorsmain rotor, which in turn rotates the twointermeshed gaterotors.

The compressor is comprised of threefundamental components which rotateand complete the work of the compres-sion process. This typically includes acylindrical main screw with six helicalgrooves and gaterotors with 11 teeth.The rotational axes of the gaterotors areparallel to each other and mutuallyperpendicular to the axis of the mainscrew.

This side view cross-sectional drawing of a Vilter oil flooded Single Screwillustrates the suction and the discharge ports as well as the various sealsand drive shaft.

SingleScrewCompressorsDesign&Operation

GaterotorSupport

Gaterotor

Annular ContactBall Bearings

Journal Bearing Parallex Slide System

Main Screw

Main Bearings Main Rotor

Drive Shaft

Shaft Seal

LabyrinthSeal

The VSM Single Screw Compressor has one main rotor and two gaterotors.All bearings are pressure fed with oil.

Telephone: (414) 744-0111Fax: (414) 744-3483

E-mail: info.vilter@emerson.com

Vilter Manufacturing LLCP.O. Box 8904

Cudahy, Wisconsin 53110-8904www.vilter.com

VSMSingleScrewCompressor

Discharge Manifold

Discharge Port

Journal Bearing

Gaterotor

TM

Radially and Axially BalancedMain Screw

Electronic OpticalSlide Actuator

Star Gaterotor

Pressurized Seal Chamber forIncreased Reliability

Variable Volume Slide 1.2 to 7.0 Ratio

Variable Capacity Slide 10% to 100%

TM

TheWorld’s Best CompressorsFor Industrial Refrigeration

Shaft Seal SystemA shaft seal system prevents any of the process gas

from leaking around the drive shaft of the main screw to theenvironment. The oil flooded Single Screw compressor hastwo seal types; the standard single mechanical face seal ora triple mechanical face seal with purge capabilitiesdepending on the process requirements. The stationarycarbon face of the seal rides on a hydrodynamic film of oilon the rotating mating ring which is fixed on the shaft. Theoptional triple seal allows various options including a purgeand vent to be connected to the housing thus adding a sec-ondary safety buffer during operation. The incorporation ofthis seal is shown in the cross-section of the oil flooded gasend.

DesignEach rotating assembly within the gas end has two sets

of bearings. A typical oil flooded Single Screw compressorconsists of two rotating gaterotor assemblies and a mainscrew assembly, each having one pair of angular contactbearings to maintain axial position of the assembly and acylindrical roller bearing to support the opposite end. All ofthe bearings are pressure fed with oil. The oil, upon drain-ing from the bearings, is drawn into the suction of the mainscrew and is discharged with the process gas and injectedoil. Since the main screw has no loads except for gravity,the bearings are considered over designed since they aredetermined by the required shaft diameter for the appliedhorsepower. The Single Screw design does not restrict thebearing sizes for the gaterotor supports. As a result, thebearings are optimized for maximum reliability.

Slide DesignThe dual slide design on the Vilter Single Screw com-

pressor offers the highest level of flexibility and perform-ance optimization for screw compressors. This designactually has two slides per compression side of the gasend. The two slides are commonly referred to as thecapacity slide and the volume slide. The capacity slidemoves from positions of 20% to 100% of flow to allow thecompressor to match the system flow requirements.Although lower flow rates are possible, they are not rec-ommended since this reduces the amount of oil flowingthrough the gas end and may result in overheating. Thevolume slide allows the discharge port to be positioned inthe optimum location depending on the capacity slidelocation, the properties of the gas and the injectant.

A unique feature of the dual slide design is that itallows the compressor to start completely unloaded. Thisis unlike any other screw compressor. When both slidesare in the open position an unrestricted flow path throughthe compressor is created. If for any reason the gas endis completely full of oil, the position of the slides on startupwill allow the oil to be swept out of the gas end thus pre-venting the possibility of hydraulic lock. The slides alsoallow the operation at extremely low ratios down to 1.2.However, the recommended operating points for optimumdesign efficiency occurs at pressure ratios of 2.0 andgreater. Due to their design, Single Screw compressorsare able to operate more efficiently and reliably with high-er suction pressures and lower ratios than other types ofscrew compressors.

Since the capacity and volume slides operate in paral-

lel (not in series like other types of screw compressors),an important feature of the Single Screw compressor isthe ability to operate with optimum efficiency even at partload conditions. Other types of screw compressors havedual slides which operate in series. This results in one ofthe slides blocking off some of the porting behind theother slide creating a restriction and performance penaltyat part load conditions.

ConclusionThe Vilter single screw compressor with the 5/15-year

warranty and ParallexTM slide system makes it the most effi-cient and reliable compressor in the world. It’s superior toany other single screw and most certainly every twin screw.

Thousands of single screws are in operation worldwidefor gas compression, air conditioning, refrigeration, andpetrochemical industries.

CAPACITY CONTROLThe maximum vol-ume of gas istrapped in thegroove.

Approximately 50%of the volume of thegroove is trappedand allowed to becompressed.

Approximately 20%of the volume of thegroove is trappedand allowed to becompressed.

VOLUME RATIO CONTROLSThe discharge portopens early in thecycle allowing onlya small reduction involume and a smallincrease in pres-sure.

The discharge portopens later in thecycle allowing asignificant reductionin volume and asignificant increasein pressure.

The slide andresulting dischargeport location are in themaximum positionresulting in themaximum reduction involume and amaximum increase indischarge pressure.

CAPACITY & VOLUME RATIO CONTROLSThe capacity slide isset to compress themaximum (100%) ofthe swept volumewhile the volume slideis set to allow a mini-mal increase in dis-charge pressure.

The capacity slide isset to compress themaximum (100%) ofthe swept volumewhile the volume slideis set to allow a maxi-mum increase in dis-charge pressure.

Rotation

Capacity Slide atMaximumCapacity

�

Capacity Slide atPart LoadCapacity

�

Capacity Slide atMinimumCapacity

�Maximum

Volume Ratio

IntermediateVolume Ratio

MaximumCapacity and

Maximum VolumeRatio

MaximumCapacity and

Minimum VolumeRatio

MinimumVolume Ratio

�

��

Rotation

Rotation

Rotation Rotation

Rotation

Rotation

Rotation

ParallexTM slide system —It’s the key to part load effi-ciencies far superior to twinscrew compressors. Capacityand volume slides (with anexpanded volume ratio of 1.2to 7.0) move independently ofeach other based on load,eliminating over or under com-pression and saving motorhorsepower.

Oil Cooling Options—• Thermosyphon• Water Cooled• Liquid Injection• V-Plus

� �

TheoryThe compression cycle begins after suction gas fills the

top and bottom grooves of the main screw at the suctionend of the casing. Since the screw compressor has agaterotor(s), the compression process occurs simultane-ously on opposite sides of the screw; the top and bottom.As the main screw rotates, it in turn drives thegaterotor(s). The engagement of the gaterotor with ascrew groove traps the suction gas and begins the com-pression process. As the screw rotates, the engagementof the gaterotor continues, thus reducing the initial volumeof the groove and increasing the pressure in the groove.Once again this occurs simultaneously on opposite sidesof the screw.Finally, as the main screw rotates toward the comple-

tion of the compression cycle, the groove aligns with aport in the housing at the discharge end of the casing.The gas and any liquid in the groove are radially dis-charged through the port into the discharge plenum.Since there are six grooves in the main screw, the com-pression process simultaneously occurs six times in twolocations per revolution of the screw. Operation at 3600RPM results in 21,600 simultaneous compression strokesat the top and bottom grooves per minute and a relativelysmooth flow of discharge gas.

Balanced LoadingOne advantage of the Single Screw compressor is the

fact that there are no net radial or axial forces exerted onthe main screw or drive shaft components due to the work

of compression. Since the compression process occurssymmetrically and simultaneously on opposite sides of thescrew, the forces due to compression are canceled out.The only vertical loads exerted on the main screw bear-ings are due to gravity. Since the discharge end of thescrew is vented to suction, the suction gas pressure isexerted on both ends of the screw resulting in balancedaxial loads.The Single Screw has an inherent design advantage of

reduced loading during the compression process. This isdue to the fact that the gaterotor tooth area decreases asthe gas pressure in the groove approaches dischargepressure. When the gaterotor first engages with the mainscrew the compression process begins. As rotation con-tinues, the gaterotor tooth area exposed to the gas pres-sure increases. The resultant force creates the axial loadson the gaterotor assembly. Approximately half waythrough the stroke, or when the radial axis of the gaterotoris perpendicular to the rotational axis of the main screw,the maximum area of the gaterotor is exposed to the gaspressure. As the compression cycle continues, the pres-sure within the groove increases but the area of thegaterotor exposed to the discharge pressure continues todecrease. The lower loads transmitted to the componentsand bearings result in higher reliability. At the end of thestroke, the area of the gaterotor has been reduced to zeroas it disengages from the main screw.Another design feature of the Single Screw compres-

sor that enhances reliability is the loads on the gaterotorassemblies are well defined and isolated from the mainscrew. Since the gaterotor assemblies are independent

and do not interfere with the rest of the main screw body,bearings can be sized for maximum reliability.

Sealing During CompressionSealing is accomplished by the combination of preci-

sion running clearances and an injected liquid(coolant/lubricant) which is allowed to leak through andthus seal the clearances during the compression process.In the Single Screw compressor, this liquid must also haveadequate viscosity to lubricate the bearings. The liquid isswept into the groove during the suction process and alsoinjected into the compression groove during the compres-sion process to maximize sealing of the running clear-ances.Due to the rotation of the screw, centrifugal force

impels the injected liquid to the circumferential clearancevolume between the screw and the housing. This mini-mizes the leakage described as cascading. Cascading isdefined as the leakage from the high pressure groovepast the land separating the grooves into the trailing lowpressure groove. Another inherent attribute of the SingleScrew design is that there is more surface area on thelands near the discharge end of the groove than near themiddle of the groove. This attribute also minimizes leak-age from the highest pressure region of the groove.Another area where the leakage is minimized is betweenthe high pressure end of the groove to the volume behindthe screw which is at suction pressure. This potential leakpath is sealed by means of a non-contacting hydrodynam-ic seal known as a viscoseal, windback seal, or labyrinthseal.

BALANCED LOADING

The single screw com-pressor has no radialor axial loads on themain screw.

COMPRESSION PROCESSThe gas is trapped inthe groove at suctionpressure.

As the groove volumeis decreased, the pres-sure in the grooveincreases.

The gas continuesto be compresseduntil it reaches theminimum volume andmaximum pressure forthe application.

Rotation

Rotation

Rotation

START OFCOMPRESSION

COMPRESSION

END OFCOMPRESSION

Vilter’s VSM single screw compressors deliverlonger life, higher reliability and better energyefficiency than the twin screw compressorsand have fewer moving parts than reciprocat-ing compressors. The key to the single screwcompressor’s reliability is in its balanceddesign. The balance design results in ultra-lowbearing loads with significantly decreasedvibration and sound levels. The inherent bal-anced design advantages allows Vilter to offer

the exclusive 5/15Warranty, including5-years on thecompressor and15-years on thebearings. The keyto the single screwcompressor’s highefficiency is Vilter’s

exclusive Parallex™ slide system allowing thecompressor to run at optimum efficiencythrough it’s full range of capacity. Providing thehighest reliability and surpassed energy effi-ciency... The World’s Best Compressors™are available only from Vilter!

Block and bleedvalves are standard

As the groove increas-es to maximum, thegas flows into theopen grooves.

Rotation

GasIntake

➥SUCTION

Vilter Single Screw Compressor – Design and Operation

Vission 20/20TM

Microprocessor Control

• Reliable Operation• Enhance Communications• Easy to Use• Flexible and Expandable

DISCHARGE PROCESSThe gas in the grooveis at dischargepressure. The mainscrew aligns with thedischarge port in thehousing and pushesthe gas through theport into the dischargechamber.

All of the gas that wastrapped in the grooveis pushed out. Thevolume of the grooveis reducedto zero.

Rotation

Rotation

DischargePort

Opening

GasDischarge

➥

START OFDISCHARGE

END OFDISCHARGE

DischargePort

Opening

TM

The World’s Best CompressorsFor Industrial Refrigeration

VSM Specifications

VSS Single Screw CompressorFrom Nominal 750 CFM thru 3000 CFM

Vilter Base Ratings (a) Standard Unit Dimensions and Weights (b)Model Ammonia R-22 Connection Sizes Length Width, Single Width, Dual Height ShippingNumber CFM Tons BHP Tons BHP Suction Discharge Oil Filter Oil Filters Weight (lbs)

VSM-152* 152 52 76 50 78 3 3 8'-2" 3'-7" 3'-11" 5'-9" 3800VSM-152E* 57 79 60 85VSM-182* 177 61 84 58 87 3 3 8'-2" 3'-7" 3'-11" 5'-9" 3800VSM-182E* 68 88 70 96VSM-202* 202 72 93 67 98 3 3 8'-2" 3'-7" 3'-11" 5'-9" 3950VSM-202E* 79 98 81 107VSM-301 305 107 133 101 136 3 3 8'-2" 3'-7" 3'-11" 5'-9" 4100VSM-301E 111 139 119 147VSM-361 353 136 151 118 155 3 3 8'-2" 3'-7" 3'-11" 5'-9" 4100VSM-361E 139 158 139 168VSM-401 405 146 169 135 175 4 3 8'-2" 3'-9" 3'-11" 5'-9" 5000VSM-401E 161 178 160 190VSM-501 502 185 202 173 207 4 3 8'-2" 3'-9" 4'-0" 6'-11" 6150VSM-501E 203 213 199 220VSM-601 609 229 241 211 237 4 4 9'-9" 3'-11" 4'-5" 7'-3" 6700VSM-601E 252 254 245 255VSM-701 691 260 272 239 264 5 4 9'-9" 3'-11" 4'-5" 7'-9" 6900VSM-701E 285 287 276 283

(a) Tons and BHP based on + 20°F and 95°F; 10°F liquid subcooling, saturated suction.Ratings for other refrigerants are available, consult Vilter for more informationon.

(b) Dimensions and weights are approximate, and are based on use with thermosiphon plate oil cooling, standard size oil separator and standard motor.* Models operate at 1775 RPM; all others operate at 3550 RPM

VILTER

VSM Single Screw CompressorFrom Nominal 150 CFM thru 700 CFM

Single Screw Ammonia

Heat Pumps

The World’s Best CompressorsFor Industrial Refrigeration

TM

Harness Your Heat...Don’t Reject It

Vilter Single Screw Ammonia Heat Pumps

Conventional Food and Beverage Processing PlantsUtilize Two Opposing Paths of Energy

Refrigeration Heat Energy OUT

Vilter Single Screw Ammonia Heat Pumps Harness the Heat from Refrigeration and Bridge the Gap for the Beneficial Use of Rejected Heat

High pressure Vilter Heat Pump Compressors allow plants to conserve energy by transferring refrigeration waste heat into useful hot water heating, while reducing or eliminating hot water boilers

and the fossil fuels they consume.

• Convert Waste Heat to Hot Water, Up to 195° F (90° C)• Reduce or Eliminate Hot Water Boilers• Retrofit Existing Ammonia Refrigeration Systems• High Coefficient of Performance (COP) at Full or Part Load

Refrigeration systems absorb heat but then reject it back into the atmosphere.

Simultaneously, plant demands for hot water, such as process room clean-up activities, use

fossil fuel energy to heat water.

Fossil Fuel Heat Energy IN

Single Screw Ammonia Heat Pump

Single Stage Scavenging Heat Pump System

Condensing

Desuperheating

Subcooling

Oil Cooling

Ammonia Refrigeration SystemsOil Cooling& Desuperheating

Available Waste Heat

Single Screw Ammonia Heat Pump

High Temperature AmmoniaPressure and Temperature

°F psia psig cuft/lb °C barA

90.0 180.76 166.06 1.6588 32.2 12.4695.0 195.91 181.21 1.5319 35.0 13.51100.0 212.01 197.31 1.4163 37.8 14.62105.0 229.09 214.39 1.3108 40.6 15.80110.0 247.19 232.49 1.2144 43.3 17.04115.0 266.34 251.64 1.1262 46.1 18.36120.0 286.60 271.90 1.0452 48.9 19.76125.0 307.98 293.28 0.9710 51.7 21.23130.0 330.54 315.84 0.9026 54.4 22.79135.0 354.32 339.62 0.8397 57.2 24.43140.0 379.36 364.66 0.7817 60.0 26.16145.0 405.70 391.00 0.7280 62.8 27.97150.0 433.38 418.68 0.6785 65.6 29.88155.0 462.45 447.75 0.6325 68.3 31.88160.0 492.95 478.25 0.5899 71.1 33.99165.0 524.94 510.24 0.5504 73.9 36.19170.0 558.45 543.75 0.5136 76.7 38.50175.0 593.53 578.83 0.4793 79.4 40.92180.0 630.24 615.54 0.4473 82.2 43.45185.0 668.63 653.93 0.4174 85.0 46.10190.0 708.74 694.04 0.3895 87.8 48.87195.0 750.64 735.94 0.3633 90.6 51.75200.0 794.38 779.68 0.3387 93.3 54.77205.0 840.03 825.33 0.3156 96.1 57.92

Single Stage Scavenging Heat Pump System

Ammonia Heat Pump Scavenging System

Condensing

Host Oil Cooling& Desuperheating

SubcoolingScavenger Oil Cooling& Desuperheating

Existing Refrigeration System Single Stage Heat Pump Scavenging System

Single Screw Ammonia Heat Pump

SuctionPressure

SSTDischargePressure

SDTNominal

WaterFlow

Heat Recovered

Total Absorbed

PowerCOP

psig (barg) °F (°C) psig (barg) °F (°C) GPM (m3/hr) mBTUH (kW) HP (kW) unitless

VSS-291 178 (12.1) 94 (34.5) 478 (32.5) 160 (71) 72 (16.4) 4874 (1429) 305 (228) 6.28

VSS-341 178 (12.1) 94 (34.5) 474 (32.2) 159 (70.5) 84 (19.1) 5657 (1658) 354 (264) 6.28

VSS-451 178 (12.1) 94 (34.5) 468 (31.9) 158 (70) 126 (28.6) 8540 (2503) 517 (386) 6.49

VSS-601 178 (12.1) 94 (34.5) 469 (31.9) 158 (70) 149 (33.9) 10041 (2943) 599 (447) 6.59

* Based upon compressors operating at 3550 RPM (60 Hz)

Single Stage Ammonia Heat Pumps Heat Water from 55°F to 155° F

Compressor Model

A scavenging heat pump system is designed to pull heat out of an existing refrigeration system by diverting ammonia discharge gas away from refrigeration system condensers to the suction inlet of the heat pump system. Vilter single screw compressors are designed to handle the high suction pressures required of this duty, and deliver the very high discharge temperature vapors for water heating in order to make use of the refrigeration system’s waste heat. In heating water to moderate temperatures, up to 160° F (71° C), single stage single screw heat pump systems provide optimal performance (COP’s) due to the duty’s relatively low differential pressures, up to 350 psid.

Single Stage Ammonia Scavenging Heat Pump Package

Single Screw Ammonia Heat Pump

Two-Stage Scavenging Heat Pump System

Condensing

Host Oil Cooling& Desuperheating

Subcooling

2nd Stage Oil Cooling& Desuperheating

1st Stage Oil Cooling & Desuperheating

Ammonia Heat Pump Scavenging System

Single Screw Ammonia Heat Pump

TWO-STAGE HEAT PUMP SCAVENGING SYSTEMEXISTING AMMONIA REFRIGERATION SYSTEM

1ST STAGECOMPRESSOR

OIL COOLEROIL COOLER

EXISTINGCOMPRESSORS

SYSTEMCONDENSOR

MAIN SYSTEM LIQUID

MAIN DISCHARGE GAS

EQUALIZING

MAIN RECEIVER

INLET WATERSUBCOOLER

OUTLET WATER

LOW STAGEDESUPERHEATER

INTERCOOLER

CONDENSER

HIGH STAGEDESUPERHEATER

2ND STAGECOMPRESSOR

LEVEL CONTROLLER

Existing Refrigeration System Two-Stage Heat Pump Scavenging System

Two-Stage Ammonia Scavenging Heat Pump Package

Single Screw Ammonia Heat Pump

Two-stage scavenging heat pump systems are utilized where the desired water temperatures are higher than those provided by single stage systems. Higher differential water temperatures correlate to higher differential pressures in heat pump compressors. By splitting the heat pump design from a single stage to a two-stage system, superior COP’s are realized in achieving very high water temperatures, up to 195° F (90° C). Vilter single screw compressors employed to satisfy the high pressures and temperatures of two-stage ammonia heat pumps operate reliably and efficiently at such intensive duties due to their naturally balanced axial and radial design.

SuctionPressure

SSTDischargePressure

SDT PowerNominal

WaterFlow

Heat Recovered

Total Absorbed

PowerCOP

psig (barg) °F (°C) psig (barg) °F (°C) HP (kW) GPM (m3/hr) mBTUH (kW) HP (kW) unitless

Low VSS-451 178 (12.1) 94 (34.5) 371 (25.2) 141 (60.5) 383 (286)High VSS-291 366 (24.9) 140 (60) 721 (49.0) 193 (89.5) 425 (317)

Low VSS-601 178 (12.1) 94 (34.5) 370 (25.2) 141 (60.5) 445 (332)High VSS-341 365(24.8) 140 (60) 720 (49.0) 193 (89.5) 498 (371)

Low VSS-901 178 (12.1) 94 (34.5) 371 (25.2) 141 (60.5) 766 (571)High VSS-451 366 (24.9) 140 (60) 721 (49.0) 193 (89.5) 768 (573)

Low VSS-1051 178 (12.1) 94 (34.5) 370 (25.2) 141 (60.5) 828 (618)High VSS-601 365 (24.8) 140 (60) 720 (49.0) 193 (89.5) 867 (647)

* Based upon compressors operating at 3550 RPM (60 Hz)

15819 (4636)

18339 (5375)

808 (603)

942 (703)

1534 (1144)

1694 (1264)

Two-Stage Ammonia Heat Pumps Heat Water from 55°F to 190° F

8772 (2571)

10680 (3130)

4.27

4.45

StageCompressor

Model

4.06

4.25

130 (29.5)

158 (35.9)

234 (53.2)

271 (61.6)

The use of heat pumps to extract heat from air and water is increasingly popular, largely because the heat they deliver far exceeds the energy they consume.

Vilter engineers, collaborating with Star Refrigeration and Norsk-Kulde, made use of Vilter single screw compressors to produce the pressures and temperatures required for the system.

Emerson.com/StarRefrigeration

Courtesy of Star Refrigeration

IT’S NEVERBEEN DONEBEFORE

Stand-Alone Heat Pump System

The city of Drammen (population 60,000) needed hot water at 90° C (194° F) for their new district heating system. Using ammonia refrigerant (R-717) the project is highly efficient, greatly reduces the use of fossil fuels, and has no negative impact on the ozone layer or global warming.

The city of Drammen, Norway is embarking on a novel energy saving plan using an ammonia-based stand-alone heat pump system. When the project comes on line, all of Drammen’s hot water heating needs with be supplied with energy extracted from the frigid North Sea, greatly reducing the use and emissions of fossil fuels.

Vilter reserves the right to make changes in design and specifications without notice.Emerson and Vilter are trademarks of Emerson Electric Co. or one of its affiliated companies.

©2010 Emerson Electric Co. All rights reserved. Printed in the USAv11 3/2010

Large Capacity Oil Filter - Filters lubricating oil beforeinjection into the compressor. Internal cartridge filterremoves all particles larger than 25 microns. Filter inlet andoutlet are equipped with transducers for monitoring pres-sure drop, and shut-off valves for servicing.

ParallexTM Slide System - It’s the key to part load efficiencies far superior to twin screw compressors. Capacityand volume slides move independently of each other based on load, eliminating over or under compression and saving motor horsepower.

Oil Cooling Options —• Water Cooled• Air Cooled

Allen-Bradley Programmable Controller -The CompactLogix programmable controller with anA-B PanelView 1000 graphic display provides highperformance in a small footprint for stand aloneoperation or for integrated system control.

Applications• Gas Liquification

• Vapor Recovery

• Flare Gas Recovery

• Coal Bed Methane Recovery

• Field and Fuel Gas Boosting

• Wellhead Recovery

• Enhanced Oil Recovery

• Landfill Gas Recovery

• LNG Boil Off

• Gas Gathering

• BIO - Gas

• Digester

• CO2

• Nitrogen

• Hydrogen

• Refrigerant

•Displacements from 310 to 2,048 CFM

• Variable capacity control 10-100%

• Variable volume ratios 1.2 – 7.0

• Compression ratios 2 – 20

• Electronic actuators are weatherproofand conform to Class 1, Group C&D,Division 2 Classification

• Balanced main rotor with no axial orradial loads

• Parallex™ Slide System for maximumoperating efficiency

• Low Bearing Loads noHydrodynamic- bearings

• High suction pressure capability is standard

• Clockwise rotation models available

• Low noise levels

• Low maintenance costs

Compressor-Features The Vilter Advantages

Part Load Energy Consumption – Single Screw vs. Twin Screw

Single Screw with Parallex Slides

Typical Twin Screw with Variable VI Ideal HP

% Capacity % Savings 75% 5% 50% 10% 25% 20%

Percent Capacity

Perc

ent o

f Ful

l Loa

d Po

wer

100%

90%

80%

70%

60%

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Isen

trop

ic E

ffici

ency

(%)

Parallex Slide System

Single Slide Fixed Volume Ratios

Compression Ratio

100%

90%

80%

70%

60%

50%

40%

30%

20%

10%

0%

2.2 3.6

5.0

0 5 10 15

Isentropic Efficiency Comparison Between Variable and Fixed Volume

Vilter’s VSG single screw gas compressors deliverlonger life, higher reliability and better energy efficiencythan twin screw compressors and have fewer movingparts than reciprocating compressors. The key to thesingle screw compressor’s reliability is in its balanceddesign. At the core of the positive displacement rotarycompressor is a single main rotor intermeshed with twoopposing gaterotors. The balanced design results inultra-low bearing loads with significantly decreasedvibration and sound levels. The key to the single screwcompressor’s high energy efficiency is Vilter’s exclusiveParallex™ slide system allowing the compressor to runat optimum efficiency through its full range of capacity.Providing the highest reliability and unsurpassed energyefficiency…The World’s Best Compressors are availableonly from Vilter!

Standard Construction:

• Main bearings – Roller and ball type angular contact thrust.

• Gaterotor bearings – Roller and ball type angular contact thrust.

• Hand wheels or optical slide valve motor for capacity and volume control. Suitable for Class 1, Group C+D, Div. II.

• Variable Vi - Independent volume control and capacity control for improving efficiencies.

• Separate prelube oil pump with TEFC drive motor.

• Lube oil piping is carbon steel, using socket weld or butt weld connections. Threaded connections are kept to a minimum.

• ASME designed oil separator with coalesing oil filter.

• CompactLogix programmable controller with an A-B PanelView 1000 graphicdisplay

• Separate stop and check valves for both suction and discharge lines.

Process Gas Circuit:

• Suction Gas Stop and Check Valve.

• Suction Line Strainer – The strainer is stainless steel mesh construction and suited to Process Gas applications.

• Process Gas/Oil Separator – The separator is capable of removing the oil from the discharge gas stream and is an ASME-coded vessel which uses five stages of separation to achieve an oil loss of below 4 PPM.

• Discharge Oil Separator Relief Valve.

Injection Oil Circuit:

• Oil Prelube Pump with TEFC motor.

• Oil Cooler/Temperature Control Valve – An oil cooler, either air or water cooled,must be used to remove the heat of compression from the oil stream. A two waytemperature control valve is used to maintain precise oil injection temperature tothe compressor VIA PID loop control in PLC.

• Oil Filtration – Filtration down to 25 microns nominal. Optional dual filters are recommended to allow replacement of one cartridge while the compressor continues running with the other cartridge in service.

• Oil Heater –Oil heaters are supplied to maintain oil temperature of at least 90°Fwhen the compressor is not running.

Available Options:

• Stainless steel lube oil circuit.

• Suction bypass connection for fuel gas booster application.

• Dual oil pumps.

• Dual oil filters.

• Water cooled or air cooled oil coolers.

• High & Low ambient temperature options.

Note – Because the oil system on the VSG compressor utilizes discharge gas pressure as the means to movethe injection oil through the system, it must be remembered that all components of the oil system areexposed to full discharge pressure and must be pressure rated accordingly.

Unit Features

Flow Diagram (Figure 1)

The control system for the VSG compressor

must protect the machine from running outside

of normal operating conditions. This is accom-

plished by providing operators with alarms when

operating parameters have reached an abnormal

condition, and by automatically stopping the

compressor before these conditions can cause a

unit failure.

Safety Setpoints:

• Low Gas Suction Temperature

• High Gas Discharge Temperature

• Low Oil Separator Start Temperature

• Low Oil Separator Run Temperature

• Low Oil Injection Temperature

• High Oil Injection Temperature

• Low Suction Pressure

• High Discharge Pressure

• Prelube Oil Pressure

• Low Oil Pressure

• High Starting Oil Filter

Differential Pressure

• High Running Oil Filter

Differential Pressure

• High Motor Amperage Limit

Alarm and Shutdown Annunciation/Indication

Pressure

There are four pressure transducers to read

system pressures as listed below (Figure 1).

PT1 Suction pressure transducer

(-15.0 - 400 PSIG) measures the gas

suction pressure into the compressor

housing.

PT2 Discharge pressure transducer

(-15.0 - 400 PSIG) measures the

discharge pressure of the process gas in

the separator.

PT3 Oil Filter Inlet pressure transducer

(-15.0 - 400 PSIG) measures the oil

pressure as it enters the oil filter canisters.

PT4 Oil Manifold pressure transducer

(-15.0 - 400 PSIG) measures the oil

pressure downstream of the oil filter as the

oil is injected into the compressor.

TemperatureThere are four temperature readings for

processor control, as listed below (Figure 1).

RTD1 Suction temperature RTD measures

the temperature of the incoming suction

gas.

RTD2 Discharge temperature RTD measures

the temperature of the gas/oil mixture as

it is discharged from the compressor

housing.

RTD3 Oil Separator temperature RTD

measures the temperature of the oil in

the separator sump.

RTD4 Oil Injection temperature RTD

measures the temperature of the oil as it

is injected into the compressor.

Additional Instrumentation

• Motor current transformer

• Optical actuators for capacity and volume

slide indication

Other Options:

• Remote start/stop input

• Remote alarm/trip output

Instrumentation

Additional pressure transducers may be required and installed by the

customer for pressure readings at customer specified points such as

process gas discharge pressure from the package boundary, cooling

water pressure to and/or from the oil cooler, etc.

Additional RTD’s may be required and installed by the customer for

temperature readings at customer specified points such as discharge

gas temperature from the package boundary, cooling water

temperature to and/or from the oil cooler, gas aftercooler temperature,

etc.

In most cases, the safety setpoints described

will have settings which are dictated by

process requirements, and not necessarily

mechanical constraints of the compressor.

Process pressures and temperatures may vary

considerably depending on the application of

the compressor. The VSG compressor is

designed to operate in a broad range of

applications. Minimum and maximum values

for each safety setpoint are provided, while

precise settings for the safety setpoints must

be derived for each installation.

VSG VSG VSG VSG VSG VSG VSG VSG VSG VSG VSG VSG VSGDescription 301 361 401 501 601 701 751 901 1051 1201 1551 1851 2101Rotor Diameter (mm) 205 205 205 240 240 240 280 280 310 310 350 350 350Gaterotor Diameter (mm) 195 205 216 225 240 252 268 280 298 310 331 350 368TheoreticalDisplacement 305 353 405 502 608 691 802 906 1101 1229 1526 1790 2118CFM at 3550 RPMMax. H.P. 3600 RPM* 300 H.P. 650 H.P. 725 H.P. 865 H.P. 1000 H.P.Max. Allowable Torque 444 ft. lbs. 962 ft. lbs. 1280 ft. lbs. 1280 ft. lbs. 1479 ft. lbs.Rotor Speed (RPM) 1200-4800 1200-4000 1200-3800 1200-3600Direction of Rotation CCW Facing Drive End CW Facing Drive End CCW Facing Drive EndDrive Type Direct Drive, Electric Motor, Gas EngineBuilt-in Volume Ratio From 1.2 to 7.0 (Continuously Variable Automatic, or Manual Control)Capacity Range From 10% to 100% (Continuously Variable Automatic, or Manual Control Available)Standard Oil Separator Design (PSIG)** 400 350

Bare Comp. MAWP** 515 485 450 (PSIG)Max. PressureDifferential (PSIG)***

325

Min. Inlet Temp (°F) -50°FMax. Inlet Temp (°F) 180°FMax. Disch. Temp (°F) 210° (Contact Vilter for increased temperature limits)Max. Oil Temp (°F) 190° (Contact Vilter for increased temperature limits)

Application Guidelines

To ensure the successful operation of the VSG compressor, the

guidelines described below should be followed.

Proper lubrication is critical to the operation of the VSG compressor.

The compressor relies on the injected oil to absorb and remove the

heat of compression, to seal the compression chambers formed in the

flutes of the screw, and to lubricate all moving parts. For this reason,

it is imperative that the oil chosen be of correct viscosity, and that

sufficient oil flow be provided at all times, using an auxiliary oil

pump when necessary. The oil chosen must be compatible with the

process gas, to prevent absorption of the gas into the oil, which

would dilute the oil and reduce the viscosity. Also oil filtration to 25

micron nominal particle size is required to ensure that only clean oil

is injected into the compressor. For assistance in choosing the correct

oil for the application and in sizing an auxiliary oil pump, consult a

Vilter representative.

Injection oil temperature must be closely controlled for optimum

performance. Oil temperature must be maintained a minimum of

15 - 20°F above the gas mixture dewpoint at anytime to prevent con-

densation or liquid knockout from occurring within the compressor.

Gas composition plays a role in the performance of the VSG

compressor as well. While the VSG is capable of handling a wide

variety of gases, if H2S is present in the process gas in any concen-

tration, special oil additives are required to protect the compressor

from corrosion. Levels below 100 PPM of H2S allow the standard

warranty to apply.

Typical gases handled: Natural Gas, Landfill Gas, Carbon Dioxide,

Propane, Helium, Propylene and Ammonia. Other gases will need to

be reviewed for compatibility and operational performance by Vilter.

Compressor Capacity and Design LimitationsStandard Compressor Models

* *Higher limits are available. Consult Vilter Manuafacturing LLC.**Higher discharge pressures are achievable. Consult Vilter Manuafacturing LLC. for approval.

***Higher differential pressures can be achieved. Consult Vilter Manuafacturing LLC. for approval.Note: MAWP (Maximum Allowable Working Pressure). The relief valve setting must be below the MAWP. The relief valve is usually set 10% lower than the MAWP.

VSG Unit Dimensions & Specifications

Models VSG 301-701 Models VSG 751- 2101

Standard Connection Sizes Unit Dimensions (Approximate)

A B CD Approx.

Vilter Suction* Discharge* Optional ShippingModel Length Width Height Oil Cooler Weight (lbs.)

VSG-301 3" 3" 8'-10" 4'-2" 6' 7-3/4" 3600VSG-361 3" 3" 8'-10" 4'-2" 6' 7-3/4" 4150VSG-401 4" 3" 8'-10" 4'-2" 6' 7-3/4" 4150VSG-501 4" 3" 8'-9" 3'-8" 7'-6" 10-3/4" 5500VSG-601 4" 4" 9'-10" 4'-0" 7'-10" 10-3/4" 6000VSG-701 4" 4" 9'-10" 4'-0" 7'-10" 10-3/4" 6000VSG-751 6" 4" 12'-0" 3'-7" 8'-0" 16" 5300VSG-901 6" 4" 12'-0" 3'-7" 8'-0" 16" 5350VSG-1051 6" 6" 13'-2" 4'-1" 8'-8" 16" 6600VSG-1201 6" 6" 13'-2" 4'-1" 8'-10" 16" 6800VSG-1551 8" 6" 14'-0" 5'-8" 10' 17" 9200VSG-1851 8" 6" 14'-0" 5'-8" 10' 17" 9300VSG-2101 10" 6" 14'-0" 5'-8" 10' 17" 9500

VSG Unit Dimensions

* Dimensions shown are approximate and should not be used for construction.

Models VSG 301-701, above, are shown with a standard C-Flange motor mount, single oil filter and standard water-cooled oil cooler

which is noted by the D dimension on the drawing. Models VSG 751-2101 drawings illustrate the optional dual oil filter and the option-

al remote mounted oil cooler which can be air cooled.

It is important to note that all VSG models can be fitted with single or dual oil filters, water-cooled oil cooler or remote mounted oil

cooler.

A

C

B D A

B

C

D