Packager
Standards
For Heavy Duty
Balanced Opposed
Reciprocating Compressors
ARIEL CORPORATION
35 BLACKJACK ROAD, MOUNT VERNON, OHIO 43050
TELEPHONE: 740-397-0311 • FAX: 740-397-3856
VISIT OUR WEB SITE: www.arielcorp.com
EC-018694, 1-31-13: Revision based on customer suggestions.
SECTION 2 (ER-56.02) - Page 1, 5a, 3rd bullet: Changed “affect horsepower and flow” to “increase compressor power requirements”. Changed “cause detrimental effects on” to “negatively affect”.
SECTION 3 (ER-56.03) - Page 2, #6: Added “JGH:E:K:T 2-throw frames with pipeline cylinders and all“.
SECTION 4 (ER-56.04) - Page 1, #5: Added “or long weld neck flanges”. Page 3, #9: Replaced with verbiage from Page 1, #3a. Page 4, “Relief Valves”, #3: Changed “Provide back-flow protection on any pilot operated relief valve” to “Pilot operated relief valves must include a back-flow protection feature when “. Page 5, #6: Deleted “up to and including cooler bypass”.
SECTION 5 (ER-56.05) - Page 1, #4: Added graphic. Page 1, “Torsional Analysis, 1st ¶: Changed “components” to “train combinations or loading”. Page 1, bullet points: 1st - changed “Electric motors with rotor shafts smaller than the compressor crankshaft drive stub diameter.” to “All electric motors, fixed or variable speed.” 4th - deleted “or motors:. 6th - deleted.
SECTION 6 (ER-56.06) - Page 10: Deleted “Oil Supply” verbiage. Page 13, “System Cleanliness”: Change heading to “Independent Oil Supply Filtration”; Add “Install” to front of ¶; change “5” to “10”; delete last two sentences. Figure 6-8: Added “Piping & Components” legend.
SECTION 8 (ER-56.12) - Page 1: Remove purge rate from "Packing Purge (optional)" description. Move Table 8-1 to page 2 under Atmospheric Vent System. Page 2: Re-number tables. Page 3, Purge and Vent Systems: Add purge rate sentence to ¶ #1. Change order of ¶s from 1,2,3,4 to 2,3,1,4. Page 9: Delete "Typical Control Schematic" heading. Change Figure 811 title from”Typical VVCP” to “Typical Control Schematic”. Caution statement -change “back pressure” to “backflow”. #4 - Re-write and bullet requirements.
SECTION 9 (ER-56.07) - Page 1: Added caution statement. EC-018781, 4-22-13: Revision per T. Stephens.
SECTION 9 (ER-56.07) - Page 7, “Vibration Protection”, #3: Delete “; actual vibraton limits relate to stress levels measured with strain gage equipment". Page 7, “Velocity Transducers”, 1st ¶: Change “5-250” to “10-250”. Page 8, “Impact Sensors”, 2nd ¶: Delete 3rd and 4th sentences. Page 8, “Impact Sensors”, 4th ¶: Add “Typical settings: “; delete “h” from “threshhold”; delete last two sentences. Pages 1: Add "See Ariel 89.10 (Appendix J)" to caution statement.
ADDED APPENDIX J.
ADDED LIST OF TABLES TO TOC.
EC-018901, 5-29-13: Revision per D. Hannon.
APPENDIX G (ER87.1) Page G1, Table 1: Replace "Premier Pressured Suction Pump Force Feed Lube" with "Force Feed Lubricator Pump -Ariel ER-105.8". Notes #2, #11, #13: Delete. Note #5: Replace "A CCT Proflo or Proflo Jr, a Kenco proximity switch, a" with "A Whitlock DNFT or proximity switch". Notes #7: Add ""or ER-57.1 (Z:U units only)".
Table of Contents
Table of Contents
i
List of Figures iv
List of Tables v
SECTION 1 - INTRODUCTION
Partial Scope Projects 1-1
Ariel Contact Information 1-2
SECTION 2 - APPLICATIONS
Packager Responsibilities 2-1
Guaranteed Performance 2-2
Performance Testing 2-2
SECTION 3 - SKID DESIGN AND FABRICATION
Package Design Requirements 3-1
Head End Support Required Features 3-3
Head End Support Adjustment 3-3
SECTION 4 - PROCESS PIPING SYSTEMS
Process Piping Systems
4-1
Scrubber Design and Installation Requirements 4-1 Piping Design, Installation, and Package Construction Requirements 4-1
Pulsation Bottles 4-2
Pulsation Bottle Installation 4-3
Discharge Bottle Support Adjustment 4-4
Relief Valves 4-4
Gas Coolers 4-4
SECTION 5 - DRIVER POWER RATING, COUPLING AND DRIVE SYSTEM
Driver Power Rating 5-1
Electric Motors 5-1
Torsional Analysis 5-2
Coupling and Drive System 5-2
Auxiliary-End Torsional Vibration Amplitude Limits 5-4
SECTION 6 - LUBRICATION
Lubricant Terminology
6-1
Frame Oil System
6-2
Components
6-4
Oil Strainer 6-4
Oil Pump & Regulating Valve 6-4
Oil Cooler 6-4
Oil Temperature Control Valve 6-5
Oil Filter 6-5
Compressor Pre-lube System 6-5
Oil Heaters 6-6
Viscosity 6-8
Oil Pressure 6-9
Oil Temperature 6-10
Oil Maintenance 6-10
Cylinder and Packing Lubrication
6-10
Force Feed System Components 6-10
Oil Supply Filter 6-10
Force Feed Lubricator 6-11
Rupture Disc Assembly 6-11
Pressure Gauge 6-11
Distribution Blocks 6-11
Over-Pressure Pin Indicator (Optional) 6-11
Fluid Flow Monitor and Cycle Indicators (see Section 1) 6-12
Balance Valves 6-12
Check Valves 6-12
Flushing Oil (Optional) 6-12
Common Oil Supply 6-12
Independent Oil Supply 6-13
System Cleanliness 6-13
Cylinder Lubrication 6-13
Rate Calculation Notes 6-16
Lubricator Cycle Time 6-16
System Operation
6-17
Purging the Force Feed Lube System 6-17
Force Feed Lubricator Adjustment 6-17
Lubricant Characteristics
6-18
Lubricant Base Stock 6-18
Petroleum-Based Lubricants (Mineral Oils) 6-18
Synthetic Lubricants 6-18
Polyalphaolefins (PAO) - Synthesized Hydrocarbons 6-18 Organic Esters - Diesters and Polyolesters 6-18
Polyalkylene Glycols (PAG) 6-19
Lubricant Formulations
6-19
R&O Oil 6-19
Compounded Cylinder Oils 6-19
Engine Oil 6-19
Used Engine Oil 6-20
Liquids in Gas 6-20
SECTION 7 - WATER-COOLED PACKING
Coolant System Requirements 7-2
SECTION 8 - PACKING AND DISTANCE PIECE VENT SYSTEMS
Vent and Drain Connections 8-1
Atmospheric Vent System 8-2
Flare Vent System 8-2
Purge and Vent Systems 8-3
Purged Vent System for Long Two-Compartment Distance Piece 8-3 Purged Vent System for Short Two-Compartment Distance Piece 8-4 Purged Vent System for Single Distance Piece with Sweep Purge 8-5
Piping Manifold Size Considerations 8-5
Monitoring a Purge and Vent System 8-5
Variable Volume Clearance Pocket Vents 8-6
Pneumatic Capacity Control Devices 8-7
Fixed Volume Clearance Pockets 8-7
Suction Valve Unloaders 8-7
Installation Notes 8-8
SECTION 9 - INSTRUMENTATION
Ariel Supplied End Devices
9-3
Main Bearing and Packing Case Temperature Sensors 9-3
Force Feed Lubrication System Monitoring 9-3
Shutdown Switch 9-4
Proximity Switch 9-4
Vibration Protection (packager supplied)
9-7
Vibration Switch 9-7
Velocity Transducers 9-7
Accelerometer Transducers 9-7
Impact Sensors 9-8
SECTION 10 - PACKAGE ASSEMBLY AND RUN TESTING
SECTION 11 - START-UP, SERVICE, AND PARTS
Compressor Manual Content 11-1
APPENDIX A - ER-26
Hold-down Bolting to Resist Shaking Forces and Couples in Reciprocating
Compressors
A-1
Requirements A-1
APPENDIX B - ER-10.4.01
Warranty Notification - Installation List Data B-1
APPENDIX C - ER-10.4.02
Warranty Notification - Installation List Data C-1
APPENDIX D - ER-10.5.1
Ariel Warranty Administration Procedures
D-1
APPENDIX E - ER-25
Preserving Ariel Reciprocating Compressors for Storage
E-1
Preservation Materials and Equipment E-1
Preservation Procedure E-1
Storage E-4
Commissioning Compressor to Service E-4
APPENDIX F - ER-34
Protection of Non-Lube Compressor Cylinders and Distance Pieces with VCI
Powder for Shipment
F-1
Application F-1
Vendor Literature Selection for ReciprocatingCompressor Customer Manuals G-1
Notes G-1
APPENDIX H - ER-82
Soft Foot and Top Plane Flatness Checks for Proper Main Bearing Bore
Align-ment inReciprocating Compressors
H-1
APPENDIX I - ER-93
Leveling Limits for Stationary ReciprocatingCompressors
I-1
Dry Sump I-2
APPENDIX J - ER-89.10
Attachment of Wiring, Tubing, or Pipe Clamps to Ariel Compressor Cylinders J-1
List of Figures
FIGURE 5-2 Angular Coupling-Hub Face AlignmentTIR Limits 5-3
FIGURE 6-1 Standard Frame Lube Oil Schematic 6-2
FIGURE 6-2 Optional Dry Sump Frame Lube Oil Schematic - Typical 6-3
FIGURE 6-3 Thermostatic Valvein Mixing Mode 6-5
FIGURE 6-4 Viscosity vs. Temperature Graph of Different Lubricants 6-9
FIGURE 6-5 Typical Force Feed Lubricator 6-11
FIGURE 6-6 Force Feed Lubrication System Common Oil Supply 6-12 FIGURE 6-7 Force Feed LubricationSystem Independent Oil Supply 6-13 FIGURE 7-1 Compressor Packing Application Guidelines forPipeline Quality Natural Gas 7-1
FIGURE 7-2 Typical Water-Cooled Packing Case 7-1
FIGURE 7-3 Typical Packing Cooling System 7-2
FIGURE 8-1 Typical Vent/Drain Connections 8-1
FIGURE 8-2 Venting to Atmosphere 8-2
FIGURE 8-3 Venting to Flare 8-2
FIGURE 8-4 Typical Purge & Vent Packing 8-3
FIGURE 8-5 LongTwo-CompartmentVent and Purge 8-3
FIGURE 8-6 ShortTwo-CompartmentVent and Purge 8-4
FIGURE 8-7 Single Compartment Sweep Purge 8-5
FIGURE 8-8 Typical VVCP 8-6
FIGURE 8-9 Typical PneumaticFixed Volume Clearance Pocket 8-7
FIGURE 8-10 Typical Suction Valve Unloader 8-7
FIGURE 8-11 Typical Control Schematic 8-8
FIGURE 9-1 Typical Dual Element RTD Wiring Diagram 9-3 FIGURE 9-2 Suggested Force Feed Lube System Proximity Switch Shutdown Logic Diagram 9-5
FIGURE 10-1 Hot/Cold Symbols 10-1
FIGURE 10-2 Control Panel Caution Sticker 10-1
FIGURE H-1 Flatness Check Locations for Frames with Single Anchor Bolts H-2 FIGURE H-2 Flatness Check Locations for Frames with Pairs of Anchor Bolts H-2
List of Tables
TABLE 5-1 Thermal Growth, In. (mm) 5-3
TABLE 5-2 Auxiliary End Torsional Vibration Amplitude Limits for Ariel Frames 5-4 TABLE 6-1 Heat Required to Maintain Minimum Frame Temperature: kW = Ch x ∆T 6-6 TABLE 6-2 Heat Required to Warm Cold Frame and Oil: kW = Ch x ∆T / ∆t 6-7
TABLE 6-3 Oil Flush Cleanliness Requirements 6-8
TABLE 6-4 Oil Viscosity Requirements, cSt 6-9
TABLE 6-5 Cylinder/Packing Oil Recommendations for Various Gas Stream Componentsa 6-14 TABLE 6-6 Cylinder/Packing Lube Oil Base Rate, Pints/Day/Inch (Liters/Day/mm) of Bore Diameter 6-15 TABLE 6-7 Cylinder & Packing Lube Calculation, Pints Per Day (Liters Per Day) 6-16 TABLE 8-1 Distance Piece Vent and Drain NPT Connection Sizes, Inches 8-1 TABLE 8-2 Typ. Packing Vent/Drain Leakage Rates 8-2
TABLE 9-1 Required Instrumentation Summary 9-1
TABLE 9-2 Force Feed Lube System Monitors - Specifications 9-6 TABLE 9-3 Typical Vibration Levels for Ariel Reciprocating Compressors, inch/sec (mm/s) 9-7 TABLE 10-1 Max. Reciprocating Weight Differential for Opposing Throws 10-1
TABLE A-1 Hold-down Bolting - Minimum Torquesa A-2
TABLE A-2 Crosshead Guide Support Foot Hold-down Bolting - Minimum Torquesa A-2 TABLE E-1 Minimum Quantity of Cortec VpCl 329 or 322 Corrosion Inhibitor for Frames - Fluid Oz. (ml) E-2 TABLE E-2 Minimum Quantity of Cortec VpCl 329 or 322 Corrosion Inhibitor for Compressor Guide Com-partments - Fluid Oz. (ml)
E-3 TABLE E-3 Minimum Quantity of Cortec VpCI 329 or 322 Corrosion Inhibitor for Cylinders E-3
TABLE F-1 Practical Quantities of VCI Powder F-1
TABLE G-1 Vendor Literature for All Models of Reciprocating Compressors G-1
TABLE G-2 Model-Specific Vendor Literature G-1
TABLE H-1 Top Plane Flatness Tolerances H-2
TABLE I-1 Maximum Angle from a Horizontal Plane Allowed when Stationary while Running with Wet Sump - In/Ft (mm/m) of Distance [ ° ]
I-1 TABLE I-2 Maximum Angle from a Horizontal Plane Allowed in Transient Motion without Dry Sump I-2
A successful reciprocating gas compression package blends precision component selection, fabrication, sales, and service. Ariel works with the packager to lead the industry in performance as well as
reputation. This standard is a minimum requirement for packaging quality. Ariel encourages packagers to exceed this standard with the finest quality packages. The packager must conform to this standard even if it exceeds end user specifications.
Packager refers to any party incorporating an Ariel product in the manufacture and/or assembly of a
compression system. The packager must ensure that the selected compressor is compatible with the application and properly integrated into the gas compression system.
NOTE: This edition of the Packager Standards is based on current design, build, and prac-tices for reciprocating compressor packages. These standards may not apply to previously built equipment and are subject to change without notice. Depending on the source, these standards may not be controlled copies. Visit www.arielcorp.com or contact Ariel for latest revisions.
Partial Scope Projects
A partial scope project is when any entity other than the packager completes any part of “package” or compression system assembly.
Regardless of the scope offered, the packager retains the obligation to “package”, install, and commission the compressor in accordance with this standard and good industry practice. At the bid phase, the packager must clearly define the scope of supply, identify areas of concern, and inform the purchaser of partial scope requirements.
Partial scope situations:
1. The user purchases a complete compressor system or “packaged” compressor unit and chooses to
use their own construction group to install it. In this case, the packager must guide the user based on package characteristics. At minimum, guidance should include:
• Studies required for foundation design
• Anchor bolt layout and elevations for off skid equipment and piping • Anchor bolt, spherical washer, and nut requirements
• Pre-grout alignment requirements • Grouting best practices
• Direct involvement in commissioning
2. The user purchases an incomplete compression system without key components such as
inter-connecting piping and vessels, instrumentation, drivers, control systems, or coolers. At minimum, packager guidance should include:
• Applicable Ariel Packager Standards requirements • Correct sizing
• Applicable code requirements
• Anchor bolt layout and elevations for off skid equipment and piping • Anchor bolt, spherical washer, and nut requirements
• Pre-grout alignment requirements • Grouting best practices
• Oversight and verification of compliance to Ariel Packager Standards • Direct involvement in commissioning
Ariel Contact Information
Contact Telephone Fax E-Mail
Ariel Response Center 888-397-7766 (toll free USA & Canada) or 740-397-3602 (International)
740-397-1060 [email protected] Spare Parts 740-393-5054 [email protected]
Order Entry 740-397-3856
--Ariel World HQ
740-397-0311 740-397-3856 [email protected]
Technical Services [email protected]
Website:www.arielcorp.com
Ariel Response Center Technicians or Switchboard Operators answer telephones during Ariel business hours, Eastern Time - USA or after hours by voice mail. Contact an authorized distributor to purchase Ariel parts. Always provide Ariel equipment serial number(s) to order spare parts. The after-hours Telephone Emergency System works as follows:
1. Follow automated instructions to Technical Services Emergency Assistance or Spare Parts
Emer-gency Service. Calls are answered by voice mail.
2. Leave a message: caller name and telephone number, serial number of equipment in question
(frame, cylinder, unloader), and a brief description of the emergency.
Packager Responsibilities
1. Utilize the most current version of the Ariel Performance Program for compressor selection,
per-formance evaluation, pricing, and access to other application information and data.
2. Develop complete familiarity with all compressor frame and cylinder design limitations, such as:
speed, power requirements, rod load, maximum allowable working pressure, discharge tem-perature, capacity control arrangements, balance, and lubrication.
3. Properly price each compressor with all options to meet the design service. For questions, contact
Ariel.
4. When evaluating existing equipment, obtain equipment serial numbers. Check with Ariel for design
ratings of older equipment as they may differ from current ratings.
5. Understand and properly evaluate customer specifications and take necessary exceptions and
pre-cautions. Since operating conditions may change, make every effort to identify:
a. Design point conditions and any possible alternate conditions.
• Valve selection is based on operating conditions provided with the order. Multiple/alternate
ditions can affect valve application. Note startup conditions (or average first year operating con-ditions) with order for best valve selection.
• Suction valve unloader application is based on all operating conditions provided with the order.
Operating conditions and available on-site actuation pressure determine suction valve unloader design and actuation pressure. The packager must provide available site actuation pressure information to Ariel at time of order.
• Valve performance is a function of valve lift. Applications with a wide range of operating
con-ditions may require low lift valves. Low lift valves may increase compressor power require-ments. Using low lift valves to extend valve life for site conditions not normally requiring them may negatively affect valve efficiency and compressor performance. Contact Ariel for specifics before requesting low lift valves.
b. The gas analysis to properly identify and address any special components.
c. Site conditions, including ambient temperature, elevation, dust, humidity, rainfall, wind velocity,
etc., and the impact of these conditions on package design.
d. The duty cycle of compressor operation and its impact on compressor and package component
selection and design.
6. For any special application, see the Ariel Application Manual. For questions or details, contact the
Ariel Application Engineering Department. Special applications include:
a. Suction pressures below 10 psig (0.7 barg).
b. Gas with specific gravity less than 0.35 or greater than 1.5.
c. Applications such as air compression, under-balanced drilling, natural gas compression for
vehicle fuel, refinery and petrochemical process systems, acid gas, etc.
d. Drive systems such as turbines, belt drive systems, variable speed motors, etc. e. Non-lubricated compressor cylinders.
g. Wet gas (natural gas produced along with crude petroleum in oil fields or from gas-condensate
fields; it contains methane, ethane, propane, butanes, and some higher hydrocarbons such as pen-tane and hexane). SeeTABLE 6-5.
h. Discharge pressures above 2500 psig (172.4 barg).
7. Some calculations in the Ariel Performance Program may need additional explanation:
a. De-Activated Stage of Compression: In choosing this option during the selection procedure,
the program estimates horsepower and flow losses for a de-activated stage.
b. Cylinder Blow Through: For this condition, the program generates estimated results. c. Gas Property Calculation: The program calculates gas properties based on either:
• The gas analysis components entered.
• The specific gravity entered, assuming a gas composed of typical natural gas components.
Non-typical natural gas mixtures require entry of the complete gas analysis to yield proper com-pressor performance results.
Guaranteed Performance
Obtain all guaranteed performance in writing from Ariel.
Ariel guarantees a single design point as calculated by the current version of the Ariel Performance Program for each compressor manufactured. All other performance is "expected" and not guaranteed. A gas analysis is required to validate this guarantee. At this guarantee design point, performance is based on gas conditions at the cylinder flanges free of pulsation effects.
Rated capacity and power are guaranteed to a tolerance of ± 3% for specific gravity between 0.50 (14.482 molecular weight) and 0.80 (23.171 molecular weight).
Rated capacity and BHP are guaranteed to a tolerance of ± 6% for any one or more of these conditions:
1. Specific gravity greater than 0.80 (23.171 molecular weight) 2. Specific gravity less than 0.50 (14.482 molecular weight) 3. Suction pressure less than 10 psig (0.7 barg)
4. Discharge pressure greater than 2500 psig (172.4 barg) 5. Compression ratios less than 1.8
Where:
• Molecular or Molar Weight of dry air (U.S. Standard Atmosphere) = 28.964 • Molecular Weight = Relative Molecular Mass
• Specific Gravity or Relative Density = Molecular Weight of gas divided by 28.964
Performance Testing
1. Testing for guaranteed performance must occur within 90 days of commissioning. If the design point
cannot be reached in this time frame, a mutually agreed upon alternate point will be tested.
2. In questions of capacity delivered or horsepower consumed by an Ariel compressor, check these
com-mon discrepancies: inlet pressure drop, excessive interstage pressure drop, leaking bypass valves, volume decrease due to liquid drop out, gas analysis different than the quoted gas analysis, com-pressor and driver mechanical condition, driver fuel gas consumption, etc.
A skid/package mechanical analysis is required to provide a properly engineered system to the end user. The Packager or a third party conducts the analysis for all unproven
driver/compressor combinations. This is especially critical for projects such as: • Any first of a driver and/or compressor combination.
• Any first of a frame class. • Offshore platforms. • FPSO installations. • Pile-mounted skids.
NOTE: The Packager must retain any supporting calculations made by the Packager and/or consultant. The Packager must consider dynamic as well as static forces. Combined Rod Load and Unbalanced Forces and Couples data are available within the Ariel Performance Program.
Package Design Requirements
1. The skid/pedestal should transmit shaking forces to the foundation and provide adequate structural
support with proper tie-down under piping, and other critical components.
2. Provide sufficient skid stiffness and strength so the compressor mounts flat without bending or
twist-ing the compressor frame, crosshead guide, or cylinder. All frame and crosshead guide mounttwist-ing points should be supported by full depth cross members.
3. When installing equipment to the skid, ensure all mounting points are flat and parallel to compressor
feet to avoid angular and parallel soft foot and facilitate ER-82 compliance (seeAppendix H). The mounting method depends heavily on packager ability to duplicate skid flatness at installation. Meth-ods to mount the frame to the skid include:
• Grouted sole plates • Grout chocks
• Careful rail or full bed grouting • Welded steel chocks
NOTE: Flatness and parallelism can be difficult to achieve using this method. It is rec-ommended to machine steel chocks after welding to avoid angular soft foot, which requires the use of step shims or re-machining in the field. Step shims create point load-ing and will not provide adequate contact between the foot and chock.
• Threaded adjustable chocks
NOTE: Though threaded adjustable chocks have been used with success under smaller frame classes, they are not permitted under JGC:D:Z:U:B:V and KBZ:U:B:V frames. Keep in mind the compressor frame is to be the stationary component of the alignment train. 4. Provide compressor hold down bolting in accordance with ER-26 (seeAppendix A). Bolt lengths
extending through only the compressor foot and I-beam flange are typically insufficient to prevent loosening.
5. Support crosshead guide feet not only to provide vertical support, but also to prevent horizontal
move-ment perpendicular to the piston rod. Attaching any support to the deck plate alone is insufficient. Ariel recommends A-frame supports attached directly to a full depth skid member. Ariel offers cross-head guide supports for JGW and larger frames. Use of threaded adjustable chocks to support the crosshead guides requires a careful mechanical study to validate their use.
6. JGH:E:K:T 2-throw frames with pipeline cylinders and all JGC:D and larger 2-throw frames require a full width compressor pedestal (wide enough to include the guide support mount-ing feet) to control unbalanced forces and couples. Ariel recommends a reinforced
concrete-filled pedestal of common height and use of Ariel crosshead guide supports.
7. Each crosshead guide deflects an amount relative to the weight of the cylinder mounted on that
throw. See the Ariel Performance Program for estimated crosshead guide foot deflection. This esti-mate accounts only for cylinder weight. Account for the weight of attached bottles and piping if cor-recting after bottle mounting. For JGR:J:W and smaller frames, cylinder weight will not deflect the guide, but bottle weight still requires consideration. After mounting the frame and torquing the frame mounting bolts, shim the crosshead guide to achieve zero deflection when the guide support bolts are tightened. Loosen the guide support bolts, lift the cylinder, then add shims equaling the deflection value as calculated by the Ariel Performance Program to the shim pack under the crosshead guide to level it. Tighten guide support bolts per ER-63. Shims may need adjustment so crosshead top and bot-tom clearances and piston rod run out are within tolerance (see Ariel Maintenance and Repair Man-ual). Except for KBZ:U frames, shim crosshead guides between the guide feet and the support; shim KBZ:U guides under the support. On JGZ:U frames equipped with long two-compartment (L2) cross-head guide extensions, use the outboard feet under the guide extension to support the guide. Leave feet under the guide unsupported.
8. Provide sufficient skid stiffness to prevent twisting due to torque reaction between the driver and
com-pressor. Provide enough stiffness so shipment or relocation minimally affects driver/compressor align-ment. Always check and correct coupling alignment after package relocation.
9. Every installed compressor package has several mechanical natural frequencies (MNF), usually in
scrubber/bottle/cylinder system groupings. Each frequency is a function of the stiffness and mass of the entire system, including the foundation or deck.
If the system first MNF is within the operating speed range or twice the operating speed range of the package, resonant vibration occurs. Ensure the first MNF of the skid package mounted on the user foundation or deck is either less than 0.8 times the minimum compressor operating speed, or more than 2.4 times the maximum operating speed. Coordinate with the foundation or deck designer. Although not recommended, to tune a major cylinder MNF between 1 and 2 times the operating frequency, maintain the cylinder MNF above 1.5 times operating frequency. The high excitation of 1 times compressor forces combined with low level amplification up to 1.5 times the operating
frequency can cause excessive vibration.
Forward maximum/minimum speed and normal operating speed range to the end user along with a caution to examine off-skid structure, piping, instrumentation, and equipment for resonance.
10. Provide skid beams with gussets at anchor bolt locations. Anchor bolt locations should also be
sup-ported internally by cross members.
11. Well-designed crosshead guide supports provide high axial (parallel to the crankshaft) and vertical
stiffness that usually eliminate the need for head end cylinder supports (HES). If a mechanical anal-ysis predicts interference with a cylinder/guide combination MNF in the operating speed range, HES may be recommended. Use HES to supplement well-designed crosshead guide supports.
• The mechanical analysis provider should provide detail drawings of the cylinder support of
appro-priate stiffness to shift the MNF.
• It is a good practice to design provisions for HES into a skid, even if HES are not recommended. It is
relatively inexpensive to fabricate and correctly install HES if considered in the design phase.
• HES require careful adjustment and may hinder maintenance access. Improperly adjusted HES
• Some cylinders have a small pad on the bottom of the head end of the cylinder. This can be used
when only vertical support is required.
Head End Support Required Features
• HES must be adjustable to avoid cylinder stress. Adjust HES with the compressor at operating
tem-perature.
• HES must be very stiff vertically and as stiff as possible parallel with the crankshaft.
• HES must not be excessively stiff horizontally (parallel with the rod). They are not intended to
restrain rod load forces.
• Ariel recommends “clamp” style supports for most Ariel cylinders. “Clamp” style supports grip the
flange of the head end head or clearance pocket. For clamp style HES, it is critical to machine the inside diameter of the clamp to a very tight tolerance to provide as much contact area as possible.
• Attach the vertical support of the HES to the skid beam web section, not to the flange. Gussets are
required between the beam flanges.
NOTE: Supports that use gas containment bolting to attach to the cylinder require Ariel approval.
Head End Support Adjustment
Adjust the HES with the system heat-soaked and immediately after adjusting the bottle supports in accordance with the start up checklist and the maintenace schedule. Shim or otherwise adjust the support to hold the current position of the cylinder.
NOTE: Piston rod run out and crosshead running clearance checks will confirm guide/cyl-inder alignment has not been compromised.
Process Piping Systems
Scrubber Design and Installation Requirements
1. Liquids and particulates are incompressible and can negatively impact compressor performance and
reliability. Each stage of compression requires an upstream scrubber or some other device to remove both free and entrained liquids from the gas. The scrubber requires a high liquid level pro-tection system and an automated drain system. In case of abrasive particle carry-over, contact an experienced filtration system manufacturer for assistance. A debris sample may be required to deter-mine its properties, origin, and appropriate filtering techniques.
NOTE: Non-intercooled, dry gas stages of compression may not require liquid separation, but provisions must be made to remove lubricating oil, if applicable.
2. Design and construct scrubbers in accordance with good engineering practice and industry
stand-ards for two-phase separators and pressure vessels. ISO-13631 provides scrubber specifications. Provide full diameter skirts with a thickness equal to or greater than the vessel wall thickness (mini-mum 1/2 inch (13 mm)).
3. Support scrubbers with full-depth structural members.
4. Position all scrubber attachments such as relief valves, sight glasses, instrumentation, drain lines,
and tubing close to the scrubber and support as required. Bullseye style sight glasses are rec-ommended.
5. Ariel requires nozzle reinforcement pads or long weld neck flanges.
Piping Design, Installation, and Package Construction
Requirements
1. During package fabrication, ensure no grinding dust, weld slag, sand, or rain enter the compressor. When welding on the skid, attach ground connection close to the weld and never to the compressor.
2. Design and install piping without low points that could collect liquids between the scrubber and
cyl-inder; liquid slugging can result in compressor damage.
3. Design and install piping so it does not distort cylinders and/or crosshead guides. To confirm the
pip-ing imposes no distortion, check crosshead-to-guide clearance after connectpip-ing the installed unit to vessels and piping.
a. No forces or moments should exist on cylinder flanges during assembly. Prying to align flange bolt
holes or “drawing down” to pull piping into position is unacceptable. Before torquing, flange bolts should thread by hand with no flange contact. The flange gap without torque must not exceed 0.030 inch (0.76 mm) for one gasket or 0.060 inch (1.52 mm) for two gaskets with an orifice.
b. Thermal studies often require nozzle load limits, which are difficult to obtain for the many
cylinder/guide combinations and skid designs. Contact Ariel for limitations.
c. It is impractical to perform thermal analysis on a compressor with the cylinders considered rigid.
The Ariel bore deflection limit is 0.001 inch per inch (0.001 mm per mm) of bore diameter, which may be used as a cylinder deflection limit.
d. Most unacceptable cylinder deflection comes from severe pipe/bottle misalignment or improper
guide preloading. It is rare for thermal loads alone to cause significant deflection, but they can exac-erbate these problems. Unacceptably high flange forces can cause:
• Low crosshead-to-guide clearance • Low piston-to-bore clearance • Low crankshaft thrust clearance • High rod run out
• Possible cylinder knock
e. Most piping and nozzle failures are due to piping vibration. It is far better to design “on skid” bottles,
pipe, and bracing as stiff as possible to prevent mechanical resonance at low frequencies where excitation forces are highest, than to design a “soft” piping system to allow thermal growth for “on skid” piping. Consider thermal forces if using long runs of “off skid” piping. “Off skid” piping better tolerates thermal stress limiters (thermal loops, flexible bracing, etc.) because pulsation and other shaking forces are typically attenuated. Design piping with sufficient size to provide equal flow to cylinders in parallel.
4. Design piping in accordance with good engineering practice and industry standards regarding
pres-sure and temperature rating, settle out prespres-sures, flow velocity, prespres-sure drop, and material com-patibility with the gas stream.
5. Provide a blow-down vent to safely relieve system pressure for maintenance purposes. Provide a
back-flow prevention check valve for any vent or blowdown line connected to a common vent or flare header.
6. Support and clamp piping in accordance with good engineering practice. Directly attach supports to,
or directly support them by a structural member of the skid or foundation. Support from deck plate or unistrut clamps is insufficient.
7. Use gusseted band clamps with Fabreeka or an equivalent material between the clamp and pipe to
prevent fretting and corrosion. Some engineering study providers may dictate metal-to-metal contact. Do not use U-bolt style clamps.
8. Ensure piping rests on the support and is not pulled down by the clamp. Shim if needed.
9. Do not block access to the analyzer drive connection at the crankshaft centerline on the crankcase
auxiliary end.
10. Provide visual access to crankcase oil level sight glass and distribution block cycle indicators.
11. Before start-up, install inlet gas debris cone strainers with 100 mesh per inch (150 micron) screen and
perforated metallic backing in a pipe spool between the inlet scrubber and cylinder suction flange. To protect the compressor cylinder, thoroughly clean any piping or vessels downstream of the screen of all debris. Clean inlet screens regularly. Monitor inlet debris strainers by differential pressure and clean them before differential pressure approaches screen collapse pressure. To protect against screen collapse, use high differential pressure alarm/shutdown switches.
Pulsation Bottles
1. High acoustical pulsation can increase frame, cylinder, gas piping, and equipment vibrations. An
acoustical study will determine if the package requires pulsation bottles when not already required by customer specifications. An acoustical study will determine if acoustical or mechanical resonances exist that require correction. When analyzing acoustical pulsation responses, consider single-acting cylinder and all cylinder load steps. Single-acting cylinders can present the worst case scenario for acoustical analysis. High acoustically driven vibration can result from single-acting cylinder operation when not considered. Contact Ariel for information beyond that of the Ariel Performance Program.
2. Design and construct pulsation bottles in accordance with good engineering practice and industry
standards for either piping and/or pressure vessels.
3. Design pulsation bottles without traps. Traps allow liquids to accumulate resulting in liquid slugging.
Provide taps for drains and instruments on the bottles. Nozzles protruding into the bottle should be slotted to prevent liquid accumulation.
4. Install taps for temperature and pressure monitoring as close to the compressor cylinder as possible.
Install the discharge temperature shutdown probe in the 1/2" NPT tap in the cylinder discharge noz-zle provided by Ariel.
5. Position all bottle attachments such as relief valves, sight glasses, instrumentation, drain lines, and
tubing close to the bottle and support as required.
6. Construct pulsation bottles connecting two or more cylinders so as not to strain cylinder flange
con-nections or distort cylinders.
7. Ariel requires nozzle reinforcement pads.
8. If a mechanical/acoustical analysis predicts high bottle shaking forces, engineered bottle supports
and clamps may be recommended. Bottle supports may not be required on some units if the Pack-ager meets the following conditions.
a. Piping and bottles assembled to cause no strain on cylinder flanges during compressor operation. b. Crosshead guide mounting feet firmly supported and properly aligned.
c. Piping properly tied down.
d. Scrubber, piping, or any other skid attachment vibration at a natural frequency prevented during
compressor operation.
Pulsation Bottle Installation
1. Place primary discharge bottle on its adjustable supports in the lowest position. Ensure both cylinder
and bottle flange sealing surfaces are clean and free of damage prior to installation.
2. Adjust primary discharge bottle supports to raise bottle to within 0.125 inch (3 mm) of cylinder flange. 3. Lubricate and insert flange bolts to allow feeler gauge access at 0°, 90°, 180°and 270°. Confirm no
bolts are flange-bound and all bolts can be threaded in completely by hand.
4. Tighten flange bolts to 45–50 ft-lbs (61-68 Nm) to achieve metal-to-metal flange contact without
excessive force applied to the nozzles or cylinders.
5. Record preliminary feeler gauge readings at 0°, 90°, 180°and 270°per flange.
6. Place primary suction bottle on cylinders and install bolts as previously described for the discharge
bottle.
7. Verify and record all feeler gauge readings.
8. Minor adjustments to cylinder flange rotation are possible at this time. If this is necessary, crosshead
clearance and piston rod runout must be re-verified.
9. No forces or moments should exist on cylinder flanges during assembly. Prying to align flange bolt
holes or “drawing down” to pull piping into position is unacceptable. Before torquing, flange bolts should thread by hand with no flange contact. The flange gap without torque must not exceed 0.030 inch (0.76 mm) for one gasket or 0.060 inch (1.52 mm) for two gaskets with an orifice.
10. Loosen bottle-to-cylinder flange bolts and install gaskets. Confirm no bolts are flange-bound and all
a. Apply 25% of torque in criss-cross sequence. Tighten repeatedly as required for consistent torque
on all bolts.
b. Apply 50% of torque in criss-cross sequence. Tighten repeatedly as required for consistent torque
on all bolts.
c. Apply 75% of torque in criss-cross sequence. Tighten repeatedly as required for consistent torque
on all bolts.
d. Apply final torque to all flange bolts until consistent torque is achieved on all bolts.
12. Loosen primary discharge bottle adjustable supports in preparation for piping fit and startup.
Discharge Bottle Support Adjustment
Properly adjust bottle supports in accordance with the start up checklist and the maintenance schedule. Ariel recommends using the following procedure:
1. With the system heat-soaked, shut down the compressor. Loosen the bottle supports and head end
supports (if applicable) so there is no contact between the bottle and support.
2. Place a magnetic base indicator as close as possible to the bottle support with the magnetic base on a
structurally stiff skid member. Place the indicator needle at the bottom center of the bottle. Multiple supports on a single bottle require an indicator at each support.
3. Tighten the bottle supports only until there is a positive movement on the indicator: 0.003 to 0.005
inch.
4. Remove the indicators. Use a locking mechanism to prevent support bolting from loosening or
repo-sitioning if the supports do not contact the bottle when the equipment cools.
5. At this point, adjust head end cylinder supports (if applicable). See“Head End Support Adjustment” on page 3-3.
Relief Valves
1. Provide relief valves on the initial stage suction and the discharge of every stage of compression, set
to operate in compliance with ISO-13631. Install discharge relief valves upstream of each individual gas cooler section.
NOTE: Consider all possible types of equipment failure or poor operation and protection of piping sys-tems when selecting relief valve locations and settings.
2. Ensure adequate relief valve settings as well as cylinder and component MAWP's for process
settle-out pressures during shutdown.
3. Pilot operated relief valves must include a back-flow protection feature when connected to a common
vent line.
The compressor cylinder may or may not be the system component with the lowest pres-sure rating. Set relief valve based on the lowest rated connected equipment.
Gas Coolers
1. Determine if the package requires gas cooling if not already required by customer specifications.
Con-sider ambient conditions, anticipated operating conditions, geographical location, and customer requirements.
2. The discharge gas temperature predicted by the Ariel Performance Program is the expected
tem-perature at the compressor cylinder discharge flange. Account for any heat loss between the com-pressor cylinder and cooler inlet flanges and size the cooler accordingly.
4. Cooler design and construction must comply with good engineering practice and industry standards
for heat exchangers.
5. Consider associated liquid condensates in the cooler design. This includes both heat load and gas
flow from top to bottom through the cooler sections.
6. Some applications require automated temperature control to avoid excessive condensates and
and Drive System
Driver Power Rating
1. The motor power rating for electric motor-driven units, including service factor (if any), must be a
mini-mum 110% of the greatest power required for any specified operating conditions. Operating con-ditions include start-up, off-design process variations, and peak loading concon-ditions. Consider
potential excessive horsepower due to external gear and coupling losses along with process gas ves-sel, piping, and/or orifice losses. See specific electric motor application requirements under "Tor-sional Analysis"below.
2. Size internal combustion engine rated power for the greatest power required for any of the
com-pressor operating conditions plus accessory power for the specific location. Do not exceed the engine manufacturer's rating criteria for continuous duty service. This criteria specifies the amount of load and speed to apply without interruption after considering site altitude, temperature, and fuel gas composition.
Electric Motors
1. Inform motor manufacturers that reciprocating gas compressor torque varies considerably in one
rev-olution. An Ariel compressor is not a constant-load (uniform torque) device, even if driven at a con-stant speed. In severe service, peak torque may vary ±200% of the mean, repeating as often as three times per revolution. Torque peaks and torque reversals can cause motor shaft fatigue failure, espe-cially with a keyway. Ensure motor shaft strength suitability for all operating conditions of intended service. Larger Ariel compressors require robust motors with large diameter, keyless shafts for long life and successful performance.
2. When designing the motor rotating assembly, electric motor manufacturers must account for
dynamic (alternating) torques generated by the driven equipment as well as the mean torque.
3. The motor stub shaft must be only as long as needed to fully insert in the appropriate coupling hub
and ensure complete contact.
4. The motor stub shaft and the section thru the drive end bearing should equal or exceed the
com-pressor drive stub diameter. For keyless comcom-pressor drive stubs, an equivalent diameter keyed motor shaft may not be sufficient (seeFIGURE 5-1).
FIGURE 5-1 Motor Shaft to Drive Stub Coupling
5. Analyze the drivetrain to ensure there are no dangerous vibratory stresses and that current pulsation
falls below motor or switch gear limits. It is inadequate to simply specify a past satisfactory motor frame size; prove rotor inertia and shaft strength and stiffness are equal to a past satisfactory instal-lation before omitting torsional analysis.
Torsional Analysis
A torsional analysis is required to provide a properly engineered system to the end user free of any possible torsional concerns. Ariel does not conduct torsional analyses. The Packager or a third party conducts the analysis for all unproven drivetrain combinations or loading, such as:
• All electric motors, fixed or variable speed. • Steam or gas turbines.
• Gearboxes.
• Engines not previously coupled to a specific compressor frame. • High torque reversals.
Contact Ariel Application Engineering for unit specific information or a list of possible engineering firms that can perform the analysis, but there is no restriction to only these companies. A torsional analysis should include:
1. A comprehensive report, including an executive summary, introduction and purpose, analysis
lim-itations, reference documents, computation results, discussion, conclusions, and appendices (tables, figures, and other data).
2. A complete dynamic model of the electric motor shaft, coupling, and compressor formulated in terms
of lumped inertia and massless springs based on normal engineering practice and judgment to deter-mine motor shaft flexibility from manufacturer supplied information - all included in a report appendix. Data should also include computed significant natural frequencies of torsional vibration, along with their modal deflected shapes and a speed-frequency interference diagram.
3. Governing torque-effort curves identified from expected compression service and rank-ordered for
excitation potential with each curve harmonic content specified in terms of Fourier Coefficients. Con-sider high volume clearance devices and single acting cylinder operation when analyzing torsional responses. Single acting cylinders can present a worst case scenario due to a more dynamic torque effort curve.
4. A written assessment of natural frequency placements acceptability relative to excitation potentials. 5. If required, a forced, damped dynamic model assembly that includes estimates of damping at various
locations in the motor and compressor.
6. The dynamic model with appropriate excitations of all governing torque curves applied. 7. Dynamic deflections, torques, and shear stresses determined for the entire dynamic model. 8. An industry-recognized fatigue analysis of Ariel's compressor crankshaft utilizing a modified
Good-man Diagram.
9. An industry-recognized fatigue analysis of the major portion of the electric motor shaft utilizing a
mod-ified Goodman Diagram.
10. An auxiliary equipment check for sensitivity to the anticipated torsional activity.
11. An on-site torsional vibration measurement at equipment start up to confirm the analysis.
Coupling and Drive System
1. The maximum coupling size for each Ariel compressor frame model is predetermined by most
cou-pling manufacturers or torsional providers. The crankshaft stub shaft length shown on the outline drawing matches a standard industry coupling size. Do not use a coupling hub design that does not completely engage or overhangs the compressor stub shaft length unless it is thoroughly checked by
2. For all direct drive units (engine or motor), use a torsionally rigid, flexible disc coupling similar to the
Thomas or Formsprag types, unless thoroughly checked by torsional analysis.
3. Do not use couplings that grow and shrink axially due to torque loading.
4. See the coupling manufacturer instruction manual for specific coupling installation and operation
requirements.
5. Determine the appropriate interference fit between the coupling hub and the compressor shaft to
transmit torque at all operating conditions. The torque load is considered a "heavy" or "heavy alter-nating" load. Ensure the coupling hub and shaft are clean and dry before installation. If a shrink disk or other externally applied interference mechanism is used to ease hub removal, the packager and component vendor must verify the coupling can transmit the required torque without slipping or embedding into the compressor stub shaft.
6. Perform an on-site torsional vibration measurement on compressors driven by variable speed
elec-tric motors. Test through design speed ranges and anticipated cylinder unloading steps as soon after start-up as possible to confirm theoretical analysis results.
FIGURE 5-2 Angular Coupling-Hub Face Alignment TIR Limits
7. To ensure parallel and concentric
drive train alignment, position con-nected equipment so total indi-cator reading (TIR) is as close to zero as possible on the coupling hub faces and outside diameters at normal operating temperature. Do not exceed 0.005 inches (0.13 mm) on the face and outside meter, except for outside dia-meters above 17 in. (43 cm) where the angular face TIR limit is 0° 1’ (0.0167°). SeeFIGURE 5-2
• Hub O.D. > 17 in. x 0.00029 =
angular coupling-hub face TIR, in. max.
• Hub O.D. > 43 cm x 0.0029 = angular coupling-hub face TIR, mm max.)
Frame Model Thermal Growth JGM:N:P:Q 0.006 (0.15) JG:A:I 0.007 (0.18) JGR:W:J 0.008 (0.20) JGH:E:K:T 0.011 (0.28) JGC:D 0.014 (0.36) JGZ:U, KBZ:U 0.016 (0.41) KBB:V 0.018 (0.46) JGB:V 0.020 (0.51)
TABLE 5-1 Thermal Growth, In. (mm)
Center the coupling between the driver and compressor so it does not thrust or force the crankshaft against either thrust face.
For cold alignment, account for the difference in thermal growth height between the compressor and driver.
TABLE 5-1lists compressor centerline height change based on 6.5 x 10-6/°F (11.7 x 10-6/°C) and a differential
temperature of 100°F (55.6°C). Obtain driver thermal growth predictions from the driver manufacturer.
Auxiliary-End Torsional Vibration Amplitude Limits
NOTE: The following limits apply to any individual harmonic. If more than one significant individual harmonic exists at a single speed with amplitude levels near the limit, an overall level should be examined and discussed with Ariel Technical Services. Ariel provides allow-able crankshaft-torque limits to the torsional vibration analyst upon request.
Auxiliary End
Drive Design Compressor Frames Included
Acceptable Compressor Auxiliary End Vibration Limits (degrees 0-peak)
Single Chain
• All single throw frames.
• All 2 and 4-throw frames in classes JG:A:M:P:N:Q:W:R:J:H:E:K:T:C:D. • JGA/6 and JGJ/6.
• Older 6-throw JGC:D frames shipped before 9-16-02 (approximate frame serial number: F18137).
• 1 degree for first harmonic (1X).a
• 1 degree for engine induced ½ orders from ½ to 1½X.
• ½ degree for second harmonic (2X). • ¼ degree for harmonics > 2X.
• ¼ degree for engine induced ½ orders > 2X.
Dual Chain
• All 2-throw frames in classes JGZ:U. • All 4-throw frames in classes
JGB:V:Z:U, KBB:V:Z:U.
• 6-throw JGE:K:T:B:V:Z:U, KBB:V:Z:U. • Newer 6-throw JGC:D frames shipped
after 9-16-02 (approximate frame serial number: F18137) & conversions.
• 2 degrees for first harmonic (1X).
• 2 degrees for engine induced ½ orders from ½ to 1½X.
• 1 degree for second harmonic (2X). • ½ degree for harmonics > 2X.
• ½ degree for engine induced ½ orders > 2X.
TABLE 5-2 Auxiliary End Torsional Vibration Amplitude Limits for Ariel Frames
a. “X” is the operating speed of the compressor in RPM.
1. Force Feed Sprocket 2. Eccentric
Adjustment
3. Plastic Dust Plug 4. Chain
5. Lube Oil Pump
Sprocket
6. Crankshaft Sprocket 7. Force Feed Chain 8. Lube oil Eccentric 9. Force Feed
Eccentric
10. Lube Oil Chain
FIGURE 5-3 Ariel Auxiliary End Drive
Designs DUAL CHAIN DRIVE SYSTEM
Proper lubrication is vital to compressor operation and requires special attention in package design. Two independent systems lubricate a compressor; the frame oil system and the force feed system. The frame oil system is a pressurized circulating system that supplies oil to the crankshaft, connecting rods, and crossheads. The force feed system is a high-pressure injection system that supplies small quantities of oil to the piston rod packings and piston rings.
In a compressor, lubrication:
1. Reduces friction - Decreases energy consumption and heat generation. 2. Reduces wear - Increases equipment life and decreases maintenance costs.
3. Removes heat from the system - Cools moving parts and maintains working clearances. 4. Prevents corrosion - Generally provided by additives rather than the base lubricant.
5. Seals and reduces contaminant buildup - Improves gas seal on piston and packing rings, and
flushes away contaminants from moving parts.
6. Dampens shock - Reduces vibration and noise and increases component life.
Many types of oils exist, some petroleum based, others synthetic. Each oil exhibits different characteristics that suit it for a specific application.
Lubricant Terminology
VISCOSITY - Measures fluid resistance to flow. It decreases with increasing temperature. In this
document, viscosity is expressed in centistokes (cSt). Proper viscosity is the most important aspect of compressor lubrication.FIGURE 6-4illustrates viscosity differences between base stock types. Viscosity can increase with oxidation or contamination by a liquid of higher viscosity or decrease with contamination by hydrocarbon gas condensate or other liquid of lower viscosity. Oil degradation increases viscosity, unless it is multi-viscosity oil (such as SAE 10W40). In multi-viscosity oils, the viscosity improvers degrade, not the base oil itself.
VISCOSITY INDEX - Indicates the magnitude of viscosity change with respect to temperature. The
higher the viscosity index, the less viscosity decreases as temperature increases.
POUR POINT - Specifies the lowest temperature at which oil flows. It is important in cold weather
applications and in cylinder and packing lubrication with cold suction temperatures.
FLASH POINT - Specifies the lowest temperature at which oil vaporizes to create a combustible mixture
in air. If exposed to flame or high temperature, the mixture flashes into flame and then extinguishes itself. This is important in high temperature applications where oil may mix with air.
Frame Oil System
Oil Connections(see Ariel outline drawing for details) A1 Packager connection from oil pump.
A2 Packager connection to oil filter.
A3 Oil connection from compressor crankcase (oil sump). A4 Lube oil compressor inlet connection to gallery tube.
Oil flows to crankshaft main bearings, connecting rod bearings, crosshead pins, and bushings.
A5 Pressure regulating valve return connection to oil
sump, when applicable.
A6 Filter vent return connection to oil sump, when
appli-cable on some models.
A7 Oil tubing connections from frame gallery tube to top
and bottom of crosshead guides to lubricate cross-heads.
A8 Compressor crankcase oil drain (oil sump drain). A9 Pre-lube/recirculation/heater connections (4)
System Components 1. Y-Strainer.
2. Compressor driven oil pump (with safety relief valve for
pressure regulation, or in models with a separate regulating valve (6), for relief).
3. Thermostatic control valve, 170°F (77°C) nominal rating
- required (purchase separately from Ariel).
4. Pre-lube oil pump - required (shown with oil heating
circuit, when applicable).
5. Optional duplex oil filter. 6. Oil filter.
7. Pressure regulating valve with overflow return to oil
sump, when applicable.
8. Oil cooler - required. 9. Check valve.
10. Heater (when applicable). 11. Temperature indicator. 12. Pressure indicator.
13. Pressure indicator/shutdown connection. FIGURE 6-1 Standard Frame Lube Oil Schematic
Oil Connections(see Ariel outline drawing for details) A1 Packager connection from compressor-driven oil pump. A2 Packager connection to oil filter.
A3 Packager connection - oil from compressor crankcase. A4 Lube oil compressor-inlet-connection to gallery tube
and bearings.
A5 Pressure regulating valve return connection to
crank-case, when applicable on some models.
A6 Filter vent return connection to the crankcase, when
applicable on some models.
A7 Oil tubing connections from frame gallery tube to top
and bottom of crosshead guides to lubricate cross-heads.
A8 Compressor crankcase oil drain.
NOTE: SeeAppendix Ifor further details about dry sump lubrication systems.
System Components
1. Separate lube oil reservoir (oil sump) - required. 2. Heater.
3. Y-Strainer - required (supplied unmounted by Ariel). 4. Check valve.
5. Compressor driven oil pump (with safety relief valve
for pressure regulation, or in models with a separate regulating valve (13), for relief).
6. Oil cooler - required.
7. Thermostatic control valve, 170°F (77°C) nominal
rating - required (available option from Ariel)
8. Pre-lube oil pump - required (with oil heating circuit,
when applicable).
9. Optional duplex oil filter. 10. Temperature indicator. 11. Pressure indicator. 12. Oil filter
13. Pressure regulating valve with overflow return to
crankcase, when applicable for some models.
14. Pressure indicator/shutdown connection.
Components
Oil Strainer
An oil strainer installed upstream of the pump prevents debris from entering the pump and damaging it. Ariel supplies a 30 mesh (595 microns) on all JG:A:M:N:P:Q:R:J:H:E:K:T compressors and a 40 mesh (400 microns) strainer on all JGC:D:Z:U, KBB:V:Z:UJGM:N:P:Q compressors. It is located on the auxiliary end of the crankcase below oil level. For dry sump frames, the lube oil strainer ships uninstalled from the factory. The packager installs it in the piping later.
Oil Pump & Regulating Valve
The oil pump constantly supplies oil to all journal bearings, bushings, and
crosshead sliding surfaces. The crankshaft drives it by a chain and sprocket to provide adequate oil flow to bearings when the compressor
operates at the minimum speed rating (typically half of maximum rated speed). JG:A:M:N:P:Q:R:J:H:E:K:T:C:D compressors maintain oil pressure with a spring-loaded safety relief valve within
the pump head. To adjust, remove the dust cap to expose the safety relief valve adjustment screw.
JGZ:U and KBB:V:Z:U compressors maintain oil pressure with a separate regulating valve. Ariel sets the spring-loaded safety relief valve within the pump head to about 75 psig (5.2 barg) to prevent high oil pump discharge pressures that could damage the pump. Do not adjust the pump safety relief valve except with a new pump installation.
Oil Cooler
An oil cooler is required to remove heat from the frame lube oil.When sizing an oil cooler, consider temperature and flow rate of both cooling medium and lube oil. Insufficient cooling water flow rate is the primary cause of high oil temperatures. Mount cooler as close to the compressor as possible with piping of adequate size to minimize pressure drop of both lube oil and cooling medium.
The Application Manual lists required cooling water temperature and flow rate to properly
cool oil with Ariel supplied coolers. The Ariel Performance Program lists oil heat rejection
data for each frame in the frame details section (contact Ariel for details).
Thermostatic control valve configuration may vary from this schematic depending on valve size. Valve con-nections A-B-C are marked on the valve.
FIGURE 6-3 Thermostatic Valve in Mixing Mode
Oil Temperature Control Valve
The lube oil system requires a thermostatic valve to control compressor oil temperature. A
thermostatic valve is a three-way valve with a temperature sensitive element. As the oil heats, the sensing element opens the third port in the valve.
Ariel recommends a thermostatic valve with a 170°F (77°C) element. Install the valve in mixing mode to more directly control oil temperature into the frame (seeFIGURE 6-3).
Oil Filter
All compressor frames require oil filters to remove particle contamination that can damage equipment and oil. Contaminants that damage equipment include wear particles from equipment , airborne particles such as dust or sand, and particulates in new oil. Contaminants that damage oil include oxidized oil components and air bubbles.
• Ariel filters are not designed for reverse flow often caused by pumping oil out of the compressor
through the filter. This can invert and tear the filter media, sending dirty oil to crankshaft bearings.
• With canister style filters, always drain oil filter housing before element removal or dirty oil will be sent to
crankshaft bearings.
• Ariel cartridge filters have a 24 month shelf life from the date of manufacture, and an install-by date is
stamped on the top of each filter. Discard any filter exceeding the install-by date.
JG:A:M:N:P:Q:R:J, JGH:R:K:Y/2/4, and JGC:D/2 compressors ship with simplex, spin-on,
non-bypassing, resin-impregnated filters as standard. Spin-on filters carry a 5 micron nominal and 17 micron absolute rating. The Beta ratings are ß5 = 2 and ß17 = 75. Many spin-on filters fit an Ariel compressor, but very few meet filtration ratings of Ariel filters. Do not use after-market filters.
JGE:K:T/6, JGC:D:B:V/4/6, JGZ:U, and KBB:V:Z:U compressors ship with simplex or duplex cartridge style pleated synthetic filters as standard. Cartridge filters are rated as 1 micron nominal and 12 micron absolute filters. The Beta ratings are ß1 = 2, ß5 = 10 and ß12 = 75.
Compressor Pre-lube System
Ariel compressors must be pre-lubed anytime the crankshaft is turned and prior to starting. Ariel strongly recommends an automated pre-lube system to extend driveline component life.
Ariel requires automated pre-lube systems for compressors that meet any of the following criteria:
• Electric motor driven compressors.
• Unattended-start compressors, regardless of driver type. • Compressor models JGC:D:Z:U:B:V and KBZ:U:B:V.
SeeFIGURE 6-1for pre-lube circuit design.
NOTE: The pre-lube return into the frame must be upstream of the oil filter.
For on-demand compressor applications, the pre-lube pump can circulate oil continuously through the bearings while on standby.
Ariel requirements are based on a pre-lube pump sized for 25% of frame oil pump flow to ensure oil flow to bearings, bushings, and oil-filled clearances prior to turning or start-up (see the Ariel Performance Program for frame oil pump flow rates).
Pre-lube pressure shall be 30 psig (2.1 barg) at the oil gallery for a minimum of 2 minutes prior to turning or starting.
NOTE: A 10 to 15 minute pre-lube is required after: • Any major driveline maintenance
• The main lube oil system is drained • Oil filter replacement
Instrumentation: Automated pre-lube systems require a start permissive logic and instrumentation to
satisfy the minimum required pressure and duration at the oil gallery inlet.
It is highly recommended that the compressor low oil pressure shutdown be Class B. Inhibited time shall be no longer than 10 seconds after idle speed is achieved on gas engines or start initiation for electric motors.
If the compressor fails to achieve 45 psig (3.1 barg) oil pressure within 10 seconds after reaching engine idle speed or electric motor start initiation, ensure shutdown and correct the cause. Repeat pre-lube before each start attempt.
NOTE: If a compressor fails to start or shuts down at start-up due to low oil pressure, DO NOT re-start until the cause is corrected.
Oil Heaters
The compressor may need a frame oil heater to meet allowable oil viscosity requirements at start-up (see
TABLE 6-4). One possible heating mode maintains the compressor frame at a minimum temperature so the compressor can start immediately if needed (seeTABLE 6-1). Multiply the coefficients listed in by the differential between target oil temperature and ambient temperature to obtain the kilowatt rating for a heater.
Another mode heats oil from ambient to a minimum temperature prior to starting (seeTABLE 6-2). Multiply the coefficients listed in by the rise in oil temperature and divide by target hours to obtain the kilowatt rating for a heater.
Ariel recommends circulation heaters for all units. JGZ:U:B:V, KBZ:U:B:V units use circulation heating only. Heated oil should circulate through the filter, bearings, and crossheads as well as the sump. All other Ariel compressors have at least one heater connection; four and six throw frames have two. Maximum allowable watt density for an immersion heater is 15 W/in2(2.3 W/cm2). This limit prevents oil coking on the heater element, which reduces heater efficiency and contaminates remaining oil.
Model Heater Coefficient (Ch), kW/°F (kW/°C)
2 Throw 4 Throw 6 Throw
JGM:N:Q:P 0.0086 (0.0155) --- ---JG:A 0.0094 (0.0170) 0.0179 (0.0322) 0.0261 (0.0470) JGW:R:J 0.0147 (0.0265) 0.0289 (0.0520) 0.0419 (0.0754) JGH:E:K:T 0.0252 (0.0454) 0.0492 (0.0886) 0.0731 (0.1316) JGC:D 0.0392 (0.0706) 0.0722 (0.1300) 0.1044 (0.1880) JGZ:U, KBZ:U 0.0534 (0.0961) 0.0944 (0.1700) 0.1319 (0.2374) JGB:V, KBB:V --- 0.1295 (0.2331) 0.1768 (0.3182)