Manual 14583480

Transcript

OPERATIONS AND MAINTENANCE MANUAL (OMM) FOR THE COMPRESSED NATURAL GAS (CNG), TYPE 4, Tank Assembly WITH THERMALLY ACTIVATED PRESSURE RELIEF DEVICE (TPRD) Typical Installation 4111 Series 4111-60 (60 inch length) 4111-90 (90 inch length) Document Number: CRM-5505 Revision: Original Date: 12 January 2016 Tel: © 410-871-9966, Option 4 Carleton Technologies, Inc., 711 Corporate Center Court, Westminster, MD 21157 USA EAR99 CONTROLLED TECHNOLOGY THESE COMMODITIES, TECHNOLOGIES OR SOFTWARE ARE CONTROLLED BY THE EXPORT ADMINISTRATION REGULATION (EAR). ANY EXPORT OR DEEMED EXPORT FROM THE UNITED STATES MUST ADHERE TO THE EAR. DIVERSION CONTRARY TO U.S. LAW IS PROHIBITED CRM-5505 REVISION RECORD Revision Affected Pages Orig. All Description of Revision Initial Release Date 12 Jan 2016 -i- CRM-5505 Rev. Orig. TABLE OF CONTENTS Page REVISION RECORD ............................................................................................................. i TABLE OF CONTENTS ......................................................................................................... a LIST OF ILLUSTRATIONS...................................................................................................... c FOREWORD .......................................................................................................................... d SAFETY SUMMARY ............................................................................................................... f CHAPTER 1: INTRODUCTION ........................................................................................... 1 1.1 GENERAL .................................................................................................................... 1 1.2 SCOPE ........................................................................................................................ 1 1.3 GENERAL DESCRIPTION ........................................................................................... 1 1.4 FORMS AND RECORDS ............................................................................................ 2 1.5 MEASUREMENT CONVERSION................................................................................. 2 1.6 TEMPERATURE CONVERSION ................................................................................. 2 1.7 VALIDATION OF TECHNICAL DATA........................................................................... 2 1.8 USE OF WORDS SHALL, SHOULD, AND MAY .......................................................... 2 1.9 ACRONYMS / TERMS ................................................................................................. 3 1.10 MANUFACTURER’S LABEL(S) ................................................................................. 6 CHAPTER 2: COMPONENTS AND OPERATION .............................................................. 7 2.1 CNG Tank Assembly .................................................................................................... 7 2.2 TPRD ........................................................................................................................... 8 2.3 VALVE ......................................................................................................................... 9 2.4 FOAM CAPS ................................................................................................................ 10 2.5 OPERATION ................................................................................................................ 10 2.6 LEADING PARTICULARS............................................................................................ 10 CHAPTER 3: CNG TANK ASSESMBLY HANDLING, INSTALLATION, AND STORAGE . 11 3.1 HANDLING .................................................................................................................. 11 3.2 INSTALLATION............................................................................................................ 11 3.3 STORAGE ................................................................................................................... 11 CHAPTER 4: FILLING AND DEFUELING ........................................................................... 12 4.1 GENERAL .................................................................................................................... 13 4.2 INITIAL FILLING (FUELING) ........................................................................................ 13 4.3 PURGING .................................................................................................................... 13 4.4 STANDARD FILL ......................................................................................................... 13 4.5 DEFUELING ................................................................................................................ 14 CHAPTER 5: INSPECTION ................................................................................................. 15 5.1 INSPECTION FOR 1st INSTALLATION/RECERTIFICATION ....................................... 15 5.2 MOUNTING INSPECTION ........................................................................................... 17 5.3 INSPECTION TOOLS .................................................................................................. 17 5.4 DAMAGE LEVELS ....................................................................................................... 18 -a- CRM-5505 Rev. 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CHAPTER 6: REPAIR .......................................................................................................... 23 6.1 GENERAL .................................................................................................................... 23 6.2 REPAIR TOOLS........................................................................................................... 23 6.3 REPAIR PROCEDURE ................................................................................................ 23 6.4 INSTALLATION AND REMOVAL ................................................................................. 24 CHAPTER 7: DESTRUCTION OF CONDEMMED CYLINDERS ......................................... 26 7.1 TANK DESTRUCTION ................................................................................................. 26 7.2 RESIDUAL GAS........................................................................................................... 27 7.1 TANK DESTRUCTION TOOL LIST .............................................................................. 27 CHAPTER 8: TESTING ....................................................................................................... 28 8.1 FUNCTIONAL TESTING .............................................................................................. 28 8.2 INSPECTION ............................................................................................................... 28 8.3 LEAKAGE TESTING .................................................................................................... 28 8.2 TAP TESTING.............................................................................................................. 29 CHAPTER 9: TOOLS / TEST EQUIPMENT / CONSUMABLES .......................................... 30 9.1 SCOPE ........................................................................................................................ 30 9.2 TOOLS, FIXTURES AND TEST EQUIPMENT ............................................................. 30 9.3 CONSUMABLE MATERIALS ....................................................................................... 32 CHAPTER 10: ILLUSTRATED PARTS BREAKDOWN ...................................................... 33 10.1 INTRODUCTION ........................................................................................................ 33 10.2 DETAILED PARTS LIST ............................................................................................ 35 APPENDIX A Inspection Record ....................................................................................... 36 -b- CRM-5505 Rev. Orig. LIST OF ILLUSTRATIONS Figure Title Page 1.1 2.1 2.2 2.3 5.1 5.2 5.3 5.4 6.1 6.2 7.1 7.2 8.1 9.1 9.2 9.3 9.4 10.1 Manufacturer’s Label(s) ................................................................................ 6 CNG Tank Assembly With TPRD .................................................................. 7 Isometric View of TPRD ................................................................................ 8 C350 Valve ................................................................................................... 9 Abrasion Damage ......................................................................................... 18 Cuts .............................................................................................................. 19 Impact ........................................................................................................... 20 Heat Damage................................................................................................ 21 Open End Wrench on Boss ........................................................................... 24 C350 Valve ................................................................................................... 25 Drilling ........................................................................................................... 26 Gouging ........................................................................................................ 26 Tap Test ....................................................................................................... 29 Inspection Mirror ........................................................................................... 30 Typical Depth Gauge .................................................................................... 31 Torque Wrench ............................................................................................. 31 Leak Detection Fluid ..................................................................................... 32 CNG Tank Assembly .................................................................................... 35 -c- CRM-5505 Rev. Orig. FOREWORD 1. MODELS COVERED This technical manual covers description, operation, maintenance and testing for 4111 Series, TYPE 4, CNG Tank Assembly with TPRD. This manual is written from the point of view of the 60” tank, which may also be referred to as “CNG Tank Assembly” “Tank”, or “Type 4 Tank”. 2. REFERENCES CGA C-6.4 Methods For Visual Inspection Of Natural Gas Vehicle (NGV) Fuel Tanks And Their Installations, available from: Compressed Gas Association, Inc. 4221 Walney Road, 5th floor Chantilly, VA 20151-2928 Phone: 703 788 2700, www.cganet.com CGA C-2 Recommendations for the Disposition of Unserviceable Tanks ANSI/NFPA 52 Compressed Natural Gas (CNG Tank Assembly) Vehicular Fuel Systems”, available from: National Fire Protection Association 1 Batterymarch Park, P.O. Box 9101 Quincy, MA 02269-9101 Phone: 800 344 3555, www.nfpa.org ANSI/CSA NGV2 Basic Requirements for Compressed Natural Gas Vehicle (NGV) Fuel Tanks”, available from: CSA America, Inc. 8501 East Pleasant Valley Road Cleveland, OH 44131 Phone: 216 524 4990 www.csa-america.org FMVSS 304, Federal Motor Vehicle Safety Standards: Compressed Natural Gas Fuel Tanks”, DOT, available from: Department Of Transportation, National Highway Traffic Safety Administration 400 Seventh Street, SW Washington D.C. 20590 Phone: 202 366 4000, www.dot.gov 571.304 DOT requirements- Compressed natural gas fuel container integrity. -d- CRM-5505 Rev. Orig. FOREWORD -Continued 3. CONTACT INFORMATION Cobham Mission Systems 711 Corporate Center Court Westminster, MD 21157 USA Tel: +1 (410) 871 9966, Option 4 Fax: +1 (410) 871 9960 [email protected] Carleton Technologies, Inc. is doing business as Cobham Mission Systems. The information contained in this brochure is given in good faith and is intended for guidance only. It should not be used for specifications. Questions or inquiries related to this manual can be directed to: Attention: Christopher Wilson, Engineering Services Manager Technical Publications Carleton Technologies, Inc. 10 Cobham Drive Orchard Park, NY 14127 Phone Number: 716-662-0438 Fax Number: 716-662-0747 -e- CRM-5505 Rev. Orig. FOREWORD -Continued SAFETY SUMMARY GENERAL SAFETY INSTRUCTIONS This safety summary includes general safety precautions and instructions that must be understood and applied during operation and maintenance to ensure personnel safety and protection of the equipment. Prior to performing any task the WARNINGs, CAUTIONs and NOTEs included in that task shall be reviewed and understood. WARNINGS, CAUTIONS AND NOTICES WARNINGs and CAUTIONs are used in this manual to highlight operating or maintenance procedures, practices, conditions or statements that are considered essential to protection of personnel. WARNINGs and CAUTIONs immediately precede the step or procedure to which they apply. NOTICES are used in this manual to highlight operating or maintenance procedures, practices, conditions or statements that are essential to protection of equipment. The headings used and their definitions are as follows. HIGHLIGHTS A PROCEDURE, PRACTICE, OR CONDITION, WHICH IF NOT STRICTLY OBSERVED, WILL RESULT IN INJURY TO, OR DEATH OF, PERSONNEL. HIGHLIGHTS A PROCEDURE, PRACTICE, OR CONDITION, WHICH IF NOT STRICTLY OBSERVED, COULD RESULT IN INJURY TO, OR DEATH OF, PERSONNEL OR LONG TERM HEALTH HAZARDS. HIGHLIGHTS A PROCEDURE, PRACTICE, OR CONDITION, WHICH IF NOT STRICTLY OBSERVED, COULD RESULT IN DAMAGE TO, OR DESTRUCTION OF, EQUIPMENT. Highlights an operating or maintenance procedure, condition, or statement. -f- CRM-5505 Rev. Orig. FOREWORD -Continued MATERIAL SAFETY DATA SHEETS (MSDS) Consult consumable vendors for Material Safety Data Sheets applicable to this publication. Review the Material Safety Data Sheets for specific information on hazards, effects and protective equipment requirements. GENERAL SAFETY PRECAUTIONS The following are general safety precautions that are not related to any specific procedure and therefore do not appear elsewhere in this technical manual. DANGEROUS PRESSURES Care must be taken during testing to ensure that equipment used for connecting high-pressure source is adequately rated, and all connections are tight. DO NOT WEAR FINGER RINGS / JEWELRY Remove rings, watches, and other metallic objects that may cause shock or burn hazards. Ground (earth) all equipment when working with flammable gases in a confined area, and always use gas-monitoring equipment. Do not allow air to enter a cylinder. Maintain a positive pressure of at least 5 BAR within the CNG Tank Assembly. If air enters a cylinder follow the nitrogen purge process described in Chapter 4 of this procedure, prior to filling with CNG. -g- CRM-5505 Rev. Orig. CHAPTER 1 INTRODUCTION 1.1 GENERAL This manual contains instructions for use of the Compressed Natural Gas (CNG Tank Assembly), Type 4 Tank. 1.2 SCOPE This publication provides operation and maintenance instructions for fitting, testing, troubleshooting, disassembly, cleaning, inspection, and assembly of the CNG Tank Assembly manufactured by: Cobham Mission Systems 711 Corporate Center Court Westminster, MD 21157 USA Tel: +1 (410) 871- 9966, Option 4 1.3 GENERAL DESCRIPTION Cobham Type 4 CNG Tank Assembly (part number 4111) offers an alternative for Light/Medium/ Heavy Duty NGV truck needs and is compliant with ANSI NGV2 and FMVSS 304. Cobham’s series of robust, high capacity Type 4 CNG Tank Assembly Tanks are offered in diameters ranging from 17.4” to 26” OD and overall lengths from 45” to 135” with a maximum capacity of 950 Liters. Cobham has over 20 years of expert experience in designing and qualifying lightweight high performance composite tanks for demanding mission critical and life support applications serving Space, military, life support, aviation and industrial market needs. With our Excellence in Delivery Program, overall manufacturing lead times are reduced by using innovative supply chain logistics and internal processes to provide the best possible lead times for exact quantities desired. -1- CRM-5505 Rev. Orig. 1.4 FORMS AND RECORDS Users will maintain documentation and keep records based on local requirements or equivalent. See Appendix A for a sample record keeping form. 1.5 MEASUREMENT CONVERSION If measurements, weights, dimensions, pressure, or torque values are converted to metric equivalents, they are shown in parentheses after the Standard English measurements. 1.6 TEMPERATURE CONVERSION Temperatures shown in degrees Fahrenheit use the symbol F. Celsius (Centigrade) conversion is shown after the Fahrenheit number and in parentheses with the symbol C. 1.7 VALIDATION OF TECHNICAL DATA When possible, the critical portions of technical manuals are validated at the factory by actual performance of the procedures in this Operations and Maintenance Manual. The validation process has the actual maintenance of the equipment accomplished correctly along with the specific user requirements and regulations. Any change or correction to the technical data is incorporated in the technical manual. 1.8 USE OF WORDS SHALL, SHOULD, AND MAY Within this document, the word “shall” is used to indicate a mandatory requirement. The word “should” is used to indicate a non-mandatory but preferred method of accomplishment. The word “may” is used to indicate an acceptable method of accomplishment. -2- CRM-5505 Rev. Orig. 1.9 ACRONYMS / TERMS The following list contains abbreviations and terms used in this manual: Abbreviations ALPM BAR °C CAGE CNG CTI DGE °F ft FS IAW in in H2O in-oz in-lb(s) IPA L LPM lb(s) ml mm MSDS MSL P/N PPE psi psia psig REF STD TPRD Actual Liters per Minute A unit of pressure = 72.5 psi Degrees Celsius (Centigrade) Commercial and Government Entity Compressed Natural Gas Carleton Technologies, Inc. Diesel Gallon Equivalent Degrees Fahrenheit Foot / Feet Full Scale In Accordance With Inch Inches of Water Inch Ounce(s) Inch Pound(s) Isopropyl Alcohol Liter Liters per Minute Pound(s) Milliliter Millimeter Material Safety Data Sheet Mean Sea Level Part Number Personal Protective Equipment Pounds per Square Inch Pounds per Square Inch Absolute Pounds per Square Inch Gauge Reference Standard Thermally Activated Pressure Relief Device -3- CRM-5505 Rev. Orig. 1.9 ACRONYMS / TERMS - Continued Terms Boss. A reinforced attachment point on a pressure cylinder or tank equipped with internal threads and increased wall thickness Carbon Fiber. Reinforcement fiber used in the composite overwrap. Crazing. Hairline cracking of the resin, giving it an opaque appearance. Cut Damage. Damage that breaks or cuts the composite fibers. Delamination. A separation between composite layers. Disbond. The separation of layers within a composite due to contamination, poor adhesion, or insufficient clamp up during cure. Domes. The closed ends of the fuel tank. Entrapped Air. Air volume that is trapped between the HDPE liner and the corresponding composite overwrap. Fill Line Assembly. A high-pressure line used to conduct gas through the Valve Frame. The frame encloses and supports the tanks, brackets and pressure lines. Glass Fiber. One type of reinforcement fibers used in the structural wrap. Also fiber used in the external sacrificial wrap. Glass fiber is also referred to as fiberglass. Impact Damage. Damage caused by dropping or by a blow from another object. Level 1 Damage. Minor damage that does not interfere with safe operation of the tank. Level 2 Damage. Damage that is rejectable. Rework may be allowed to return tank to service. Level 3 Damage. Damage that is not repairable and renders a tank unfit for service. Tanks with level 3 damage shall be condemned and destroyed. Maximum Fill Pressure. The maximum pressure allowed to obtain the settled Service Pressure at 70º F (21º C). In accordance with ANSI/ CSA NGV2 it is 125% of the rated Service Pressure. NGV Natural Gas Vehicle. Outer Hoop. The final layer of circumferentially wrapped fibers that is located on the sidewall of the cylinder. -4- CRM-5505 Rev. Orig. 1.9 ACRONYMS / TERMS - Continued Tank Assembly A Type 4 CNG tank with TPRD installed. TPRD Thermally Activated Pressure Relief Device. A device that will release the contained gas in specific emergency conditions including: excessive temperature, excessive pressure, or both. Resin Epoxy material in the composite overwrap which fills the space between individual reinforcing fibers. Service Life The number of years from the date of manufacture that a tank may be used. Fuel tanks shall be destroyed at the end of service life. Service Pressure. The nominal, operating, working, or “settled” pressure at a uniform gas temperature of 70º F (21º C). Valve, Manual. A device equipped with a handle installed in one of the ports of the tank that is used to open or close off the gas flow. Valve, Solenoid. A device installed in one of the tank ports that is used to open or close off gas flow that is turned on or off electrically. Vent Line. A high-pressure line used to conduct gas from a pressure relief device (TPRD) to a location outside of the vehicle. -5- CRM-5505 Rev. Orig. 1.10 MANUFACTURER’S LABEL(S) The, manufacturer’s label shall not be removed, obliterated, or defaced. Figure 1.1: Manufacturer’s Label -6- CRM-5505 Rev. Orig. CHAPTER 2 COMPONENTS AND OPERATION 2.1 CNG Tank Assembly The CNG Tank Assembly is designed to provide pressurized natural gas for automotive (land) vehicles. A Type 4 NGV2 fuel tank is defined as “Resin impregnated continuous filament with a nonmetallic liner.” They are qualified to DOT FMVSS 304, ANSI/CSA NGV2. Figure 2.1: CNG Tank Assembly With TPRD -7- CRM-5505 Rev. Orig. 2.2 TPRD – P/N 6-5983 The CNG Tank Assembly is equipped with a Thermally Actuated Pressure Relief Device (TPRD), which is located on the dome of the CNG opposite the valve. Figure 2.2: Isometric View of TPRD The TPRD is not a repairable item, but may be removed and replaced if damaged or expended if the Tank is serviceable. Contact PTD for replacement P/N 6-5983 replacement part. -8- CRM-5505 Rev. Orig. 2.3 VALVE – P/N C350 The valve information is included for reference. The 4111 Series tank assemblies have been designed to work with a C350 (or equivalent), valve. Figure 2-3: C350 Valve The Valve is not a repairable item, but may be removed and replaced if the Tank is serviceable. Contact PTD for replacement P/N C-350 replacement part. -9- CRM-5505 Rev. Orig. 2.4 FOAM CAPS – P/N 4108-3 The CNG is equipped with protective foam caps on each dome to shield against impact damage. The foam pad P/N is 4108-3. They protect the dome area of the carbon composite which is more susceptible to impact damage than the other areas of the cylinder. The Foam Pads are not a repairable item, but may be removed and replaced if damaged if the Tank is serviceable. Contact PTD for replacement P/N 4108-3 for replacement parts. 2.5 OPERATION The CNG Tank Assembly provides fuel storage for vehicular equipment. It is equipped with both a manual and a solenoid activated shut-off valve. The CNG Tank Assembly delivers 100% natural gas on demand. The nominal storage pressure is 3600 psig. The shutoff valve is equipped with 1.125-12 UNF inlet/outlet fitting. 2.6 LEADING PARTICULARS COMPONENT Gas Operating Pressure Operating Temperature Inlet Fitting REQUIREMENT Compressed Natural Gas 3,600 psi -40 to 180°F (-40 to 82°C) 1.125-12 UNF Product Type Size Dia. Length Weight 4111-60 4 278 L 21.7” (552 mm) 60” (1524 mm) 156 lb. DGE (approx) 23.2 4111-90 4 436 L 21.7” (552 mm) 90” (2286 mm) 233 lb. 36.3 - 10 - CRM-5505 Rev. Orig. CHAPTER 3 CNG Tank Assembly HANDLING, INSTALLATION AND STORAGE 3.1 HANDLING Examine composite fuel tanks, assess their condition and determine if they are safe for service. Identify minor repair procedures that may be used to prolong the useful life of fuel tanks with minor surface damage. Install if the fuel tanks are safe for service. 3.2 INSTALLATION This design is intended for strap mounting only. If the strap assemblies were removed, install the strap assemblies onto the tank per the fitting manufacturer’s specifications. Install the vent line per manufacturer’s specifications. System installations must be made per vehicle fuel system codes, in accordance with The Vehicular Fuel Systems Code, ANSI/NFPA 52, Fuel System Integrity of Compressed Natural Gas Vehicles, FMVSS No. 303, (49CFR571.303), Compressed Natural Gas Fuel Container Integrity, FMVSS No. 304, (49CFR571.304), or other equivalent standards. 3.3 STORAGE Clean the exterior of the CNG Tank Assembly and verify that the CNG Tank Assembly is depressurized. Ensure that the manual valve is in the closed position. Place unit in a suitable box or container which will prevent distortion, bending or crushing of the unit. Label the outside of the box indicating that the CNG Tank Assembly is de-pressurized and purged. Seal the box or container. Store the unit in a cool, dry environment away from direct sunlight. - 11 - CRM-5505 Rev. Orig. CHAPTER 4 FILLING AND DEFUELING 4.1 GENERAL The following section provides guidelines only and does not supersede any applicable regulations, standards or requirements of fuel storage system manufacturers. Always ground (earth) the cylinder, fuel system or vehicle whenever cylinders are being filled or defueled. Failure to do so may result in explosion or fire. Do not allow gas concentrations to form within a working environment. Test all systems in a well-ventilated area that is free from ignition sources. When working with flammable gases in a confined area, always use gasmonitoring equipment. Always remove all oxidants (including air) from a cylinder prior to filling the cylinder with flammable gas! Be alert to the fact that air may enter the cylinder whenever the cylinder has been vented or exposed to ambient pressure, including during initial filling, after valve installation or any time the system has been bled to zero pressure. During fueling (filling) and defueling, expansion or contraction of the cylinder sometimes causes snapping or popping noises. This is normal and is not a cause for concern. - 12 - CRM-5505 Rev. Orig. 4.2 INITIAL FILLING (FUELING) Purging must be conducted prior to initial fill. Purge according to section 4.3. Failure to follow the fuel system manufacturer’s instructions on filling may lead to serious injury or death! An “initial fill” is the first pressurization that occurs after the cylinder has been vented or exposed to ambient pressure, including initial filling, after valve installation, or any time the system has been bled to zero pressure. 4.3 PURGING Pressurize the cylinder to at least 5 bar (72.5 psi) with a dry, inert gas such as nitrogen. Vent the cylinder slowly to avoid condensation in the cylinder or valve. Once the system has been vented, close the valve to prevent air from re-entering the cylinder. The cylinder may now be filled with natural gas. 4.4 STANDARD FILL North American users - fill the cylinder such that the settled pressure does not exceed the marked service (working) pressure at 70°F (21°C). - 13 - CRM-5505 Rev. Orig. 4.5 DEFUELING FAILURE TO COMPLY WITH THE FOLLOWING WARNING AND CAUTION STATEMENTS MAY RESULT IN INJURY TO, OR DEATH OF, PERSONNEL, IF NOT STRICTLY OBSERVED. When working with flammable gases in a confined area, always use gasmonitoring equipment and ground (earth) all equipment. During defueling, take precautions to make sure that those performing the procedure will not be harmed if gas escapes due to a leak or broken seal. However, defueling pressure must be slightly higher than atmospheric pressure to stop air from entering the cylinder if a seal is broken. Vent gas properly through a flue or flare stack to prevent contaminating the environment and to avoid a hazardous gas accumulation. Never allow air to enter a cylinder. When disconnecting fittings (seals) during maintenance or inspection, make sure that air or debris do not enter through the opening. Fuel system inspection includes checking all attached components, such as valves, tubing, end plugs, fittings and pressure-relief devices. During inspection, make sure that all devices are securely attached. If any is loose, tighten it in accordance with the fuel system manufacturer’s instructions. - 14 - CRM-5505 Rev. Orig. CHAPTER 5 INSPECTION 5.1 INSPECTION FOR 1st INSTALLATION/RECERTIFICATION INSPECTION TOOLS: • • • • • • • • Mirror with extending handle Measuring Device, 6 inch scale Tape measure Liquid Leak Detector and plain water to rinse the detection fluid A small metal object for tapping Cloth Rags Flashlight/Drop Light Depth Gauge Inspection of cylinders shall be performed in accordance with the Compressed Gas Association (CGA) pamphlet C6.4 “Methods for External Visual Inspection of Natural Gas Vehicle (NGV) Fuel”. The user shall be responsible for applying any labels (in addition to the Cobham Label), which may be required by local jurisdictions of use. Tanks should be inspected by a trained inspector at maximum intervals of 36 months or 36,000 miles. Tanks shall have permanent labels in accordance with the applicable local regulations in addition to Cobham’s manufacturer’s label. The tank should be promptly inspected if it was involved in a fire, subjected to impact, exposed to excessive heat, or damaged by any means. Tanks that may have Level 2 or Level 3 damage (refer to paragraph 5.4) should be depressurized before inspection. If the fuel tank emits natural gas odor, loses gas pressure, rattles, snaps, or hisses it should be inspected, (except during filling operation when expansion occurs). The fuel tank should also be inspected if it is transferred to another vehicle or the installation is altered. The vehicle operator should be questioned regarding any known conditions or incidents that may have caused damage to the tank including: • • • • • • Dropping the tank Impacts to the tank Exposure to excessive heat Vehicle accidents Exposure to harsh chemicals Repairs made since its last inspection - 15 - CRM-5505 Rev. Orig. 5.1 INSPECTION FOR 1st INSTALLATION/RECERTIFICATION - Continued General Installation Inspection The guidelines in this manual were formulated specifically for a Type 4 tank. The initial inspection should include examination of the general fuel tank installation. This inspection should include: • A record of the inspection (by tank serial number) should be generated or up-dated for all inspections. For an example of an inspection record, reference the sample inspection form in Appendix A. Determine that the installation is compliant with applicable local regulations beyond requirements stated in this manual. Verify the following: • The fuel tank is being used only for storage of compressed natural gas. • The service pressure and tank serial number are clearly legible on the tank label. • The service pressure rating listed on the tank label is greater than or equal to vehicle markings. • The surface of the tank is not in contact or close proximity to objects that could cut, gouge, or abrade the surface. This includes shields, cables, tubing, and mounting bracket components. • A minimum of 1/2-inch (127 mm) clearance completely around the tank and 8 inch (20.32 cm) minimum ground clearance. • Installations in which tanks are enclosed must be vented externally. The vent line from the pressure relief device (TPRD) should be a high-pressure line, which is adequately secured to the vehicle. The vent line exit should be free of debris and oriented such that the line will not trap fluids. A vent line cap must not inhibit gas flow should the system vent. - 16 - CRM-5505 Rev. Orig. 5.2 MOUNTING INSPECTION To inspect a CNG tank that is already installed on a vehicle, ensure that the tank is clean and free of dirt or other debris. Remove shields or covers. It is not necessary to remove the tank from the vehicle. Thoroughly inspect the mounting for indications of wear or damage. The CNG Tank Assembly is designed for Strap Mounting only. Refer to the bracket manufacturer instructions for inspection of mounting hardware. Tanks that may have Level 2 or Level 3 Damage (refer to paragraph 5.4) should be depressurized before inspection. Composite Surface Inspection Damage to the composite surface can be categorized into five main types: • Cut, scratch, and abrasion damage • Impact damage • Excessive heat damage • Chemical damage • Weathering/Ultra Violet damage The depth of the area determines the damage level assigned to the composite fibers in question. Accurate depth measurement of damage requires removing all loose fibers associated with the damage. Once the loose fibers are removed, the damage level can be determined per paragraph 5.4. 5.3 INSPECTION TOOLS Refer to Chapter 9 for tool details. - 17 - CRM-5505 Rev. Orig. 5.4 DAMAGE LEVELS 5.4.1 Abrasion Level 1 Level 3 Figure 5.1: Abrasion Damage Abrasion damage may be the result of many cycles of an object rubbing on the surface of the tank or due to a few cycles under high load. Surfaces abraded under high loads will tend to appear as a group of parallel gouges. Tanks exhibiting evidence of abrasion under high loads should be examined as though the surface was subjected to impact damage (see Figure 5.3). Level 1 damage is present when there is any size area of abrasion or number of flaws less than 0.01 inches (0.254mm) deep. Level 2 damage is present when there is any abrasion between 0.01 and 0.03 inches (0.254 - 0.762mm) deep and less than 1 square inch in area. Level 3 damage is present where there is any abrasion exceeding Level 2. - 18 - CRM-5505 Rev. Orig. 5.4.2 Cut / Gouge Figure 5.2: Cuts Cut damage causes deeper fiber breaks than scratch damage. This type of damage is difficult to measure because of the loose fibers in the damaged area. Scratches in the composite surface result in surface fiber damage. Typically, scratches will be less than 0.010 inches in depth and cause only minor fiber breaks. Level 1 damage is present when there is any number of flaws less than 0.01 inches (0.254mm) deep. Level 2 damage is present when there are any number of flaws of any length between 0.01 and 0.03 inches (0.254 - 0.762mm) deep OR one single flaw between 0.03 and 0.05 inches (0.762 - 1.27mm) deep and less than 1 inch (25.4mm) long. Level 3 damage is present when there is any flaw greater than 0.03 inch (0.762mm) deep and greater than 1.0 inch (25.4mm) long OR multiple flaws between 0.03 and 0.05 inches (0.762mm - 1.27mm) deep and less than 1 inch (25.4mm) long OR any flaw greater than 0.05 inch (1.27mm) deep. - 19 - CRM-5505 Rev. Orig. 5.4.3 Impact The depth of the area determines the damage level assigned to the composite fibers in question. Accurate depth measurement of damage requires removing all loose fibers associated with the damage. Once the loose fibers are removed, the damage level can be determined. Severe structural damage can be caused by impact. Impact damage may occur during shipping, handling or while in service. Impacts may be the result of dropping the tank or due to in-service conditions such as a vehicle accident. Figure 5.3: Impact Impact damage differs from other forms of tank damage in that more severe damage may occur within the wall of the tank than at the surface of the tank. This is particularly true if the surface of the object impacting the tank is blunt and relatively smooth. The surface of a composite tank tends to return to its original shape after an impact and, therefore, does not dent like an all-metal tank. Impact damage may cause delaminations and fractures to the composite layers of the tank. Surface damage associated with impact loads may include cutting, gouging, scraping, scuffing, chipping, punctures, fiber breakage, loose fibers, resin cracking or change in coloration or appearance. The surface must be carefully examined for these indications. Accurate depth measurement of damage requires removing all loose fibers associated with the damage. Once the loose fibers are removed, the damage level can be determined. Known areas of impact and zones of detectable surface damage must be inspected for damage within the wall. Evidence of damage within the wall includes permanent deformation of the tank surface This is evidence of severe internal damage. Tanks exhibiting this type of damage shall be condemned and destroyed. Softness of the tank wall is evidence of severe internal damage. Tanks exhibiting this condition have Level 3 damage and shall be condemned and destroyed. - 20 - CRM-5505 Rev. Orig. 5.4.3 Impact - Continued Damage to tank bosses due to impact to the ends of the tank, including the valves, plumbing, and pressure relief devices, should be investigated to ensure composite damage has not been sustained. Tanks which incur impact damage may exhibit circular, oval, or linear zones of crazing of the composite surface. These zones may also be accompanied by a change in coloration. Each area exhibiting these types of indications should be subjected to the tap test. Questionable areas should also be subjected to factory inspection. Level 1 damage is present when there is a small, frosted and whitish area less than 1.5 square inches in area and no fiber cracking or damage. Or when there is any number of flaws where after removal of loose fibers the damaged area is less than 0.01 inch (0.254mm) deep. Level 2 damage is present when there are any number of flaws of any length between 0.01 and 0.03 inches (0.254 - 0.762mm) deep OR one single flaw between 0.03 and 0.05 inches (0.762 - 1.27mm) deep and less than 1 inch (25.4mm) long. Level 3 damage is present when there is any flaw greater than 0.03 inch (0.762mm) deep and greater than 1.0 inch (25.4mm) long OR multiple flaws between 0.03 and 0.05 inches (0.762mm - 1.27mm) deep and less than 1 inch (25.4mm) long OR any flaw greater than 0.05 inch (1.27mm) deep. Level 3 damage is also present if the liner is permanently creased or if the laminate is soft. 5.4.4 Disbond Level 1 damage is present when disbonding (minor separation) occurs between the outer glass wrap and the carbon, since the glass wrap is for label protection only. Level 3 N/A (see impact). Ensure that disbonding has not been caused by impact. - 21 - CRM-5505 Rev. Orig. 5.4.5 Delamination Level 1 N/A. Level 2 damage is present when damage is limited to the outer hoop only. The width of delamination may not exceed damage allowances per sections 5.4.2 and 5.4.3 criteria. Level 3 damage is present when there is any delamination exceeding Level 2 5.4.6 Heat Damage Figure 5.4: Heat Damage All NGV Fuel tanks manufactured under NGV2 or ISO 11439 have a maximum service temperature of 180°F (82.2°C). Excessive heating may occur if the tank is not properly located relative to an exhaust system or is involved in a fire. Evidence of heat damage includes darkening, charring, or sooting of the surface in the area of exposure. Severe exposure may result in resin removal and loose fibers. Other signs of heat damage are melting of the plastic on the labels and discoloration of the bosses. Tanks showing evidence of excessive heat exposure are defined as having Level 3 damage and are to be removed from service, condemned and destroyed. Level 1 damage is present when there is light discoloration. Level 3 damage is present when there is evidence of burnt or charred resin or significant areas of discoloration. Actuation of the TPRD is also evidence of Level 3 damage. - 22 - CRM-5505 Rev. Orig. 5.4.7 Gas Leakage Tanks that exhibit apparent gas leakage must be removed from service. Contact Cobham Mission Systems to report the condition and obtain information regarding additional tank testing and disposition. Cobham Mission Systems 711 Corporate Center Court Westminster, MD 21157 USA Tel: +1 (410) 871 9966, Option 4 Fax: +1 (410) 871 9960 [email protected] Tanks with confirmed gas leaks are condemned and must be destroyed. Bubbles are typically observed on the composite surface for several hours after pressurization, particularly after the initial pressurization following installation, or if the tank is empty or nearly empty. The bubbles are caused by air trapped between the liner, and composite being forced through the composite when the tank is pressurized and the liner expands. 5.4.8 Weathering Damage/Ultraviolet Damage The tank may exhibit degradation of the external coating after prolonged exposure to sunlight and weathering. This degradation may result in discoloration and/or flaking of the coating. This condition is Level 1 damage. The affected surface may be reworked after completion of the inspection process by scuffing to promote adhesion, and painting of the area with a clear polyurethane paint, IAW Para 6.3 Repair. Rework should not be accomplished on damaged fibers or in areas where other damage is present. - 23 - CRM-5505 Rev. Orig. CHAPTER 6 REPAIR 6.1 GENERAL Level 1, and some Level 2, damage may be repaired by following the repair instructions shown below. Tanks must be depressurized before repair and purged before refilling. This chapter provides the details of repair procedures for the CNG Tank Assembly that may be performed as part of normal usage. 6.2 REPAIR TOOLS NOMENCLATURE Safety Glasses Gloves Dust Mask Epoxy Dispenser ScotchBrite or fine (120 grit), sand paper Lint Free Shop Rag Isopropyl alcohol 6.3 DESCRIPTION AND USE PPE – epoxy preparation and application PPE – epoxy preparation and application PPE – epoxy preparation and application Epoxy application Prepare composite surface Clean surface Clean surface REPAIR PROCEDURE Power abrasion is not permitted. Tank Clean and lightly scuff (to promote adhesion), with ScotchBrite®. Wipe off sanding dust using a lint-free shop rag and a small amount of isopropyl alcohol. Mix two part epoxy resin, in accordance with the manufacturer’s instructions. Apply a small amount of resin to the damaged area, using the epoxy applicator, or a squeegee, ensuring that resin is fully worked into any damage. Allow to cure, following manufacturer’s instructions for ambient temperature cure. - 24 - CRM-5505 Rev. Orig. 6.4 INSTALLATION AND REMOVAL Prior to filling, purge per section 4.3 if the TPRD or Valve has been removed and replaced, or if the inside of the tank has been exposed to air. Place a 2 ¼” open end wrench on the appropriate boss and hand tighten TPRD or Valve. Tighten the TPRD or Valve with a torque wrench as described below. Figure6.1: Open End Wrench on Boss TPRD Remove and replace the TPRD as needed. Lubricate threads with Christo-Lube®, and torque to 96 ± 5 foot pounds. Do not attempt to disassemble or repair the TPRD. After filling, conduct a functional leakage check, in accordance with section 8.3. - 25 - CRM-5505 Rev. Orig. 6.4 INSTALLATION AND REMOVAL- Continued Valve Assembly Remove and replace Valve Assembly as needed in accordance with manufacturer’s recommendations. Lubricate valve threads with Christo-Lube®, and torque to 96 ± 5 foot pounds. Orient the valve assembly for easy electrical cable connection. Do not attempt to disassemble or repair the Valve Assembly. Figure 6.2: C350 Valve After filling, conduct a functional leakage check (refer to section 8.5). - 26 - CRM-5505 Rev. Orig. CHAPTER 7 DESTRUCTION OF CONDEMMED CYLINDERS 7.1 TANK DESTRUCTION A CNG tank that has been condemned must be clearly marked as “CONDEMNED” at the time of inspection. The marking shall be affixed to the manufacturer’s label. The tank must be destroyed by drilling two or more holes, one-half inch or greater in diameter, completely through the tank wall and internal liner, and gouging of the threads at the bosses. Figure 7.1: Drilling Figure 7.2: Gouging - 27 - CRM-5505 Rev. Orig. 7.2 RESIDUAL GAS Residual natural gas and/or air can be trapped between the liner and the composite after venting. Allow the vented tank (open to atmosphere) to sit for eight hours to allow the trapped gas to escape before drilling the condemned tank. The vessel will contain residual gas fumes after depressurization. Ensure that residual fumes are not ignited during destruction. Displace residual fumes with compressed nitrogen. If compressed nitrogen is not available, flush the tank with water. 7.3 TANK DESTRUCTION TOOL LIST • • • Drill with 1/2 inch (13 mm) bit Compressed nitrogen If nitrogen is not available, flush the tank with water. - 28 - CRM-5505 Rev. Orig. CHAPTER 8 TESTING 8.1 FUNCTIONAL TESTING Functional testing is required. Functional testing shall always be conducted after any maintenance or removal and repair of any component to confirm the effectiveness of the repair and readiness of the CNG Tank Assembly for use. Functional testing is intended to verify the performance of the CNG Tank Assembly and may be conducted prior to, or after use. 8.2 INSPECTION Inspect the CNG Tank Assembly, in accordance with Chapter 5, before conducting testing to ensure that the CNG Tank Assembly is in serviceable condition. 8.3 LEAKAGE TEST Leakage testing is a functional test conducted on a pressurized system. When the manual valve is opened it should open smoothly without undo resistance. After the CNG has been installed in the vehicle and the valve has been placed in the open position, apply leak detection fluid to the external joints of the valve and observe for a minimum of 2 minutes for evidence of bubbles. Also apply leak detection fluid to the TPRD plug at the opposite end of the cylinder, all fuel line joints, and any suspect areas of the cylinder. - 29 - CRM-5505 Rev. Orig. 8.4 TAP TESTING (Optional) Figure 8.1: Tap Test The tap test is a specialized test that should only be conducted by a trained, experienced technician. The information shown below is intended to inform technicians that this type of test exists. This information is not a substitute for qualified training. The tap test is performed by rapping the cylinder with a small metal object (such as a quarter), and listening for differences in sound emitted in the potentially damaged area, relative to the surrounding area. The tap test is a tool used to identify de-laminations within the composite wall and should be performed only when the composite surface has been impacted. The tap test will not reveal de-laminations from abrasion damage because abrasion damage will not de-laminate underlying layers. The tap test must be confined to the cylinder portion of the tank. False indications may be heard if this is attempted in the dome areas. Differences in sound are evidence of damage within the composite wall. Tanks exhibiting this type of damage must be removed from service. The tanks may be subjected to further field evaluation, factory inspection at Cobham Mission Systems, or be condemned and destroyed in accordance with Chapter 7. - 30 - CRM-5505 Rev. Orig. CHAPTER 9 TOOLS / TEST EQUIPMENT / CONSUMABLES 9.1 SCOPE This chapter describes the tools, test equipment and consumables used to support both performance of the CNG Tank Assembly and testing if it is necessary to verify the reason for return to the depot and to isolate faulty parts. Tests should be accomplished in a shop properly equipped for repair. Standard test equipment and fittings used to connect test equipment to the CNG Tank Assembly are the responsibility of the repair facility. 9.2 TOOLS, FIXTURES AND TEST EQUIPMENT A list of tools, fixtures, and equipment necessary for testing of the CNG Tank Assembly is listed below. Unless noted otherwise, one of each item listed is required. When specified tools or test equipment are not available, equivalent items of equal or greater accuracy may be substituted. NOMENCLATURE Torque Wrench Gas Detector Depth Gauge Ruler Tape Measure Open end wrench Inspection Mirror Flashlight or droplight DESCRIPTION AND USE TPRD & Valve Installation Detect gas concentrations Determine depth of cuts Determine length of cut Determine area of abrasion TPRD & Valve Installation Examine Composite Surface Examine Composite Surface Figure 9.1: Inspection Mirror - 31 - CRM-5505 Rev. Orig. 9.2 TOOLS, FIXTURES AND TEST EQUIPMENT - Continued Figure 9.2: Typical Depth Gauge Figure 9.3: Torque Wrench - 32 - CRM-5505 Rev. Orig. 9.3 CONSUMABLE MATERIALS A list of consumable materials required for assembly and testing is given below: SNOOP (or equivalent) ITEM (P/N OR NSN EQUIVALENT MAY BE SUBSTITUTED) Leak Detection Fluid Isopropyl alcohol Cleaning agent Nitrogen Purging Gas NOMENCLATURE ® Christo-Lube MCG 111 High Pressure Lubricant Figure 9.5: Leak Detection Fluid - 33 - CRM-5505 Rev. Orig. CHAPTER 10 ILLUSTRATED PARTS BREAKDOWN 10.1 INTRODUCTION This chapter shows the illustrations and authorized replacement parts for the CNG Tank Assembly. 10.2 DETAILED PARTS LIST The following illustration identifies, the location of parts listed in the subsequent parts list and their relationship to one another in the CNG assembly. Note: Foam Pads not Shown Figure 10.1: Top Assembly PART NUMBER 4111 Series 4111-60 4111-90 C350 6-5983 4108-3 Table 10-1: Detailed Parts List NOMENCLATURE CNG Tank Assembly 60” tank 90“ tank Valve TPRD Rotarex Y1421105 Foam Pad - 34 - QTY REF 1 1 1 1 2 CRM-5505 Rev. Orig. APPENDIX A – TEMPLATE CNG Tank Assembly Inspection Record Inspector Name Inspection Date Serial No. Model No. Expiration Date Mounting Location Vehicle Identification Number (VIN) Vehicle Mileage Examination Accept Reject CNG Tank has not exceeded service life on label CNG Tank service pressure meets rating on label Clearance around tank per section 5.1 of this manual CNG tank condition acceptable per section 5 of this manual Dome with valve condition per section 5 of this manual Dome opposite valve condition per section 5 of this manual Manufacturer’s and local regulatory labels in place TPRD condition per vendor’s recommendations and section 2.2 of this manual Valve condition per vendor’s recommendations and section 2.3 of this manual Bracket condition to bracket manufacturer’s requirements Mounting pads in good condition Interfaces free of leaks per section 8.3 of this manual Fuel lines mounted securely to fuel system manufacturer’s requirements Vent lines mounted securely fuel system manufacturer’s requirements - 35 - Comments (include damage level)