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Cryomech LNP-20 Installation, Operation And Routine Maintenance Manual

Liquid nitrogen plant
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Model LNP-20
Liquid Nitrogen Plant
INSTALLATION, OPERATION and
ROUTINE MAINTENANCE MANUAL

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Summary of Contents for Cryomech LNP-20

  • Page 1 Model LNP-20 Liquid Nitrogen Plant INSTALLATION, OPERATION and ROUTINE MAINTENANCE MANUAL...
  • Page 2 Except as expressly contained in this document, there are no other warranties granted or extended by the manufacturer. Cryomech, Inc. reserves the right to add, change, modify or delete any or all information contained herein without prior written notice. Revisions to this document may be issued at the time such changes and/or deletions occur.
  • Page 3 Contents Section 1 Overview Section 2 Warranty Section 3 Safety Section 4 Inspection and Unpacking Section 5 Specifications Section 6 Installation Section 7 Operation Section 8 Routine Maintenance Appendix Spray Lubricant Instructions...
  • Page 4 Section 1 Overview 1.1-N...
  • Page 5 The nitrogen generator uses the compressed air to produce gaseous nitrogen. The gaseous nitrogen enters the dewar where it is liquefied and stored. A Cryomech Cryorefrigerator is used to liquefy the nitrogen. The liquid nitrogen plant is fully automatic and will shut down the cryorefrigerator when the dewar is full.
  • Page 6 The main body of the manual provides a detailed discussion of everything you will need in order to install and operate the Cryomech Liquid Nitrogen Plant and to perform routine maintenance. It is divided into 8 sections. Illustrations accompany the discussion as needed for clarification.
  • Page 7 Air Compressor: The standard air compressor, if supplied by Cryomech, is a two stage, pressure lubricated compressor with a horizontal receiving tank. A pressure switch automatically maintains the compressed air pressure required by the nitrogen generator.
  • Page 8 Overview Dewar: The dewar is a stainless steel, vacuum jacketed container built for the purpose of storing liquid nitrogen with minimal boil off. The dewar is sealed from the atmosphere so that only nitrogen gas flowing from the N generator can enter it. The cold head, attached to the top of the dewar, liquefies the nitrogen gas inside the dewar.
  • Page 9 Liters per Minute Male Pipe Thread Nitrogen OFHC Oxygen-Free High Conductivity (describes a form of Copper) PSIG Pounds per Square Inch Gauge 1.4 Cryomech Contact Information Cryomech, Inc. 113 Falso Drive Syracuse, NY 13211 Phone: (315) 455-2555 Fax: (315) 455-2544 Email: cryoservice@cryomech.com...
  • Page 10 Section 2 Warranty 2.1-N...
  • Page 11 Cryomech, Inc. extends a warranty on all parts and workmanship for a period of one (1) year from the date of shipment from Cryomech. This warranty covers all non-user serviceable components of the air compressor.
  • Page 12 Warranty • The air compressor must be installed and operated according to the manufacturer’s specifications included in the air compressor’s instruction manual. Failure to follow the manufacturer’s instructions will void the warranty. See Sections 6 and 7. • If the air compressor must be bolted to the floor, please pay special attention to the mounting instructions included in Section 3 of the air compressor’s instruction manual.
  • Page 13 Section 3 Safety 3.1-N...
  • Page 14 Section 3: Safety 3.1 Safety and information symbols 3.1.1 Equipment symbols The safety and information symbol stickers placed on Cryomech Liquid Nitrogen Plants as well as Cryorefrigerators are defined below. Alternating current. The symbol signifies that alternating current is present.
  • Page 15 Safety 3.2 Warnings and cautions Warnings and cautions for the Cryomech Liquid Nitrogen Plants are listed here by subsystem. The same warnings and cautions appear in the appropriate places in the unpacking, installation, operation and routine maintenance sections of this document.
  • Page 16 Safety Section 6.2 Dewar installation WARNING Personnel, including rescue workers, should not enter areas where the oxygen concentration is below 19.5% unless provided with a self contained breathing apparatus or air-line respirator. Section 6.3 Helium compressor installation CAUTION Failure to follow these installation guidelines could result in voiding the warranty. Section 6.3.1 Prepare the compressor package location WARNING The helium compressor package must be positioned to provide easy access to the...
  • Page 17 Safety WARNING One lead of the helium compressor package is grounded. Never bypass this ground or attach the helium compressor package to an ungrounded circuit. A dangerous electrical hazard will develop. Section 6.3.4 Connect the helium flex lines to the cold head and the helium compressor package CAUTION Follow the procedure carefully when connecting and disconnecting the helium flex...
  • Page 18 Safety CAUTION The maximum inlet air temperature to the N generator /compressed air filter bank panel is 125°F (52°C). Temperatures above 125°F (52°C) will damage the filter bank components. This type of damage is not covered under the warranty. CAUTION Do not apply heat to the automatic drain valve.
  • Page 19 Safety Section 6.6.4 Connect the air compressor to the main power CAUTION A voltage deviation of more than 10% above or below the voltage rating can cause motor overheating and possible failure. Indications of operation outside that voltage range will void the compressor warranty. WARNING Be sure to follow all local electrical codes and guidelines.
  • Page 20 Safety Section 6.9 N generator/filter bank panel to dewar connection CAUTION Do not allow the nitrogen flex line to come into contact with corrosives or any type of commercial cleaning agent. Leaks caused by exposure to corrosives or commercial cleaning agents will not be covered under warranty. CAUTION Do not bend the nitrogen flex line to less than 5 inch (12 cm) radius or permanent damage may occur.
  • Page 21 Safety Section 7.5 Normal operation behavior CAUTION A dewar pressure greater than 25 PSIG will destroy the level indicator/switch. Section 7.6 Extracting liquid nitrogen WARNING Before extracting liquid nitrogen from the dewar, carefully read the following safety precautions. Improper handling of liquid nitrogen may result in serious injury or death. WARNING If a large spill of liquid nitrogen occurs, open all windows and doors to ventilate the area.
  • Page 22 Failure to maintain the system properly will void the warranty. Section 8.3 Cold head CAUTION Service to the cold head must be performed using Cryomech parts and the appropriate work instruction. CONTACT CRYOMECH IF THE COLD HEAD NEEDS SERVICING. Section 8.4 Helium compressor adsorber replacement CAUTION At no time should the Aeroquip...
  • Page 23 Safety Section 8.6 Recharge helium CAUTION When adding helium, the helium must be 99.999% pure. Contamination by other gases will result in the freezing of the contaminant gases in the cold head because their freezing temperature is much higher than that of helium. Contaminants in the helium charge will severely degrade the cold head's function and it will require factory servicing.
  • Page 24 Safety Section 8.10.2 Electrical protection device (option) WARNING Do not attempt to replace the fuses or place anything inside the enclosure until the power to the electrical protection device has been disconnected. Serious injury or death may occur. WARNING Failure to disconnect the power to the electrical protection device before attempting to replace the fuses may result in serious injury or death.
  • Page 25 Section 4 Inspection and Unpacking 4.1-N...
  • Page 26 1) Remove the top of the packing crate by unfastening the Klimp® fasteners that fasten the top to the sides and/or cutting the steel banding. 2) Check for tip indicators on the inside of the packing crate and notify Cryomech if interior tip indicators have been activated even though tip indicators on the outside were not.
  • Page 27 Check the pressure readings on both pressure gauges. If either gauge reads 5 PSIG (.34 bar) lower than the recorded value, contact Cryomech. 4.3.3 Dewar Inspect the dewar and the components attached to it for any signs of damage such as dents or scratches.
  • Page 28 4.4 Returning a system to Cryomech Preparation of helium compressor, helium and nitrogen flex lines, dewar and air compressor 1) Contact Cryomech for an RMA number and for additional detailed instructions on how to properly return system components. 2) Repackage the system:...
  • Page 29 Replace used “tip and tell” indicators with new ones (total of three per crate). 5) When the shipment is ready, please contact Cryomech for further instructions on shipping. Revisions for Section 4.2-N...
  • Page 30 Section 5 Specifications 5.2-N...
  • Page 31 Operation of the liquid nitrogen plant in any situation that does not meet the specifications in this section will void the warranty. If you plan to operate the system outside any of the specified conditions, contact Cryomech. 5.2.1 Weights and dimensions...
  • Page 32 Specifications Water Flow Rate (LPM) CP810 / CP819 / CP820 CP830 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 Water Flow Rate (GPM) Figure 5-1: Cooling water requirement* Water Pressure Drop (bar) CP810 / CP819 / CP820 CP830 10 12 14 16 18 20 22 24 Water Pressure Drop (PSI)
  • Page 33 Specifications 5.2.3 Helium compressor electrical specifications 208/230 Volt 200 Volt Parameter 60 Hz Model 50 Hz Model Nominal 208/230 VAC 200 VAC voltage Operating voltage 208 - 230 VAC 200 VAC range Frequency 60 Hz 50 Hz Phase Water Cooled Input Power Maximum: N/A kW...
  • Page 34 Operation above 100F will cause overheating and subsequent problems. If a unit must be subjected to either extreme, Cryomech must be consulted. 5.2.7 Safety Devices A number of safety switches and valves are located inside the compressor package and on the cold head.
  • Page 35 Specifications High-Pressure Atmospheric Relief Valve The compressor package high-pressure atmospheric relief valve is set at 421 ± 5 PSIG (29 ± .34 bar). At pressures above 421 PSIG (29 bar) the relief valve will open automatically and relieve pressure to the atmosphere. External Motor Overload Switch An external motor overload switch, located on the compressor module, protects the system by sensing excessive current draw and temperature.
  • Page 36 Specifications 5.3 Description of the helium compressor Power Hour Low Pressure Low Pressure Switch Meter Gauge Aeroquip Dewar High Cord Pressure Connector Gauge High Pressure Aeroquip Circuit Breaker Service Valve Cooling Water Inlet Connection Service Access Cooling Water Outlet Connection Temperature Pressure Power...
  • Page 37 Specifications Dewar Low Pressure Low Pressure Cord Power Hour Gauge Aeroquip Connector Switch Meter Circuit High Breaker Pressure Gauge High Pressure Aeroquip Service Valve Temperature Switch Reset Service Access Pressure Power Cord Switch Reset Figure 5-4: Front panel of an air cooled compressor package...
  • Page 38 Specifications 5.3.1 Front panel interfaces This section describes the function of all operator interfaces on the front panel of the CP800 Series Compressor Package, including switches and valves. It also describes the functions of all connectors, electrical cords and gauges on the front panel. Low-Pressure Aeroquip...
  • Page 39 Specifications Cooling Water Inlet Connection The cooling water inlet connection provides water to the compressor package from your facility to cool the compressor package during operation. The connector thread size is 1/4 FPT (1/4” Female National Pipe Thread). The water must meet the specifications provided in the Cooling Water Specifications table in Section 5.2.
  • Page 40 Specifications 5.4 Description of the dewar The dewar is a stainless steel, vacuum jacketed container built for the purpose of storing liquid nitrogen with minimal boil off. The dewar is sealed from the atmosphere so that only nitrogen flowing from the nitrogen generator can enter it. Attached to the dewar are the cold head, low pressure regulator, level indicator, pressure relief valves, bleed valve and extraction line.
  • Page 41 Specifications 5.4.1 Inlet Neck Assembly Pressure Gauge Nitrogen Pressure Switch Low Pressure Regulator Nitrogen Figure 5-6: Representative model Inlet Coupling of the Inlet Neck Assembly Low Pressure Regulator A low pressure regulator is attached to the top of the dewar. The regulator is set to maintain a pressure inside the dewar of 3-7 PSI (0.2-0.5 bar) above atmospheric pressure.
  • Page 42 Specifications 5.4.2 Relief Neck Assembly 10 PSIG Relief Valve Level Probe 15 PSIG High Capacity Bleed Valve Relief Valve Figure 5-7: Representative model of the Relief Neck Assembly This assembly includes the following components: Bleed Valve The bleed valve is used to release the pressure inside the dewar. 10 psi Pressure Relief Valve The primary pressure relief valve will begin to open when the pressure inside the dewar is approximately 10 PSIG.
  • Page 43 Specifications 5.4.3 Level Indicator Auto/Manual Switch 7 Pin Electrical Feed Thru If the “On” LED is blinking, the Level Indicator is in the “force fill on” mode. The fill will be requested on regardless of the level. If this light is on solid, the fill is being requested because the level is below the low level set point.
  • Page 44 Specifications 7 Pin Electrical Feed Thru Power is supplied to the level indicator/switch by the LNP control cable that connects to the 7 Pin Electrical Feed Thru on the dewar and the helium compressor package’s system I/O and AUX ports. The liquid nitrogen plant will not operate unless the dewar cord is connected to the dewar and the helium compressor, or the manual/auto switch is in the AUTO position.
  • Page 45 Specifications 5.5 Description of the N generator/filter bank panel The N (nitrogen) generator/filter bank panel consists of a pressure regulator, a series of compressed air filters, a dehumidifier, and a N generator, all attached to a wall mountable panel. The compressed air filters are necessary to remove particulates, moisture and oil from the compressed air supply before it enters the nitrogen generator.
  • Page 46 Specifications Water Filter The water filter removes condensed moisture and particulate matter from the compressed air supply. The trapped moisture drips to the bottom of the filter bowl and is expelled through the automatic drain valve. The filter is fitted with a visual indicator to monitor the condition of the filter element.
  • Page 47 Specifications 5.6 Description of the air compressor The standard air compressor, if supplied by Cryomech, is a two stage, pressure lubricated compressor with a horizontal receiving tank. The air compressor supplies the generator/filter bank panel with the required compressed air flow rate and pressure necessary to produce 98% pure nitrogen gas.
  • Page 48 Specifications Inlet Air Filter The inlet air filter removes dust and particulates from the ambient air before it enters the air compressor’s compression chamber. The filter element is replaceable. Oil Pressure Gauge The oil pressure gauge displays the pressure in the air compressor’s oil lubrication circuit. Oil Filter The oil filter traps contaminants in the air compressor’s lubrication oil.
  • Page 49 Specifications 5.7 Description of the refrigerated air dryer (option) The optional refrigerated air dryer removes moisture from the compressed air stream before it enters the N generator/filter bank panel. The dryer operates automatically and requires periodic maintenance. The manufacturer’s user manual is included with the dryer.
  • Page 50 Specifications Dewpoint Indicator The dewpoint indicator provides a visual indicator of the compressed air’s dew point. Condensate Drain Line The condensate drain line is a plastic tube that carries away the moisture removed from the compressed air. Inlet Air Port The inlet air port is a 3/8”...
  • Page 51 Specifications 5.8 Description of the electrical protection device (option) The optional electrical protection device (EPD) monitors the supply voltage for phase loss as well as for overvoltage and undervoltage conditions. If one of the fault conditions occurs, the EPD disconnects the power to the entire system. The EPD is housed in a wall mountable electrical enclosure.
  • Page 52 Specifications Fuse Block The fuse block is fitted with two fuses to protect the monitoring relay. Fuse Cover with Indicator Light A fuse cover with indicator light is fitted over each fuse. The indicator lights are illuminated only when a fuse is blown. Two spare fuses are shipped with the system inside the enclosure.
  • Page 53 Specifications Power Indicator (U) The power indicator is a green LED. It illuminates whenever the monitoring relay is supplied with power. Relay Indicator (R) The relay indicator is a green LED. It illuminates when the monitoring relay is closed and power is being supplied to the LNP.
  • Page 54 Specifications Revisions for Section 5.2-N Date Description of revisions made 25SEP14 Initial Release 5-24...
  • Page 55 Section 6 Installation 6.1-N...
  • Page 56 Installation Section 6: Installation 6.1 System installation The entire section on the installation of the liquid nitrogen plant should be reviewed before installing the system. CAUTION Failure to follow these installation guidelines could result in voiding the warranty. The liquid nitrogen plant should be located in a well ventilated area. The ventilation is necessary for proper cooling of air cooled helium compressor packages as well as to disperse the oxygen that is released from the nitrogen generator during operation.
  • Page 57 Installation 6.2 Dewar installation  Confirm that the physical space containing the dewar has an ambient temperature in the range of 45 to 100°F (7 to 38°C).  If the dewar is installed in an enclosed, confined space, an oxygen monitor/alarm should be installed to protect against a deficient oxygen level.
  • Page 58 Installation  Locate the helium compressor package within 10 ft (3 m) of the dewar. If greater separation is required, longer helium flex lines, as well as a longer dewar cord, will be needed.  Position the helium compressor package so there is sufficient space around it for changing the adsorber.
  • Page 59 Installation 1) The system MUST be connected to a dedicated circuit breaker. The breaker must be mounted near the helium compressor package, within easy reach of the operator, and must be marked as the disconnecting device for the system. Specifications for circuit breakers vary according to the system’s operating voltage.
  • Page 60 Installation 1) Remove all dust caps and plugs from the helium flex lines, helium compressor package and cold head and place in tool kit. Save dust caps and plugs for future use. 2) Make certain the flat gaskets are present and properly seated in the compressor’s and cold head’s male Aeroquip...
  • Page 61 Installation Hold this wrench Turn this wrench Figure 6-2: Connecting the low-pressure flex line to the low-pressure port on a cold head 6) With the same wrenches, connect the other helium flex line to the high-pressure port on the helium compressor package front panel. The high-pressure port is marked “HIGH”.
  • Page 62 Installation 2) Assure that the LNP control cable is sufficiently long to reach the level indicator on the dewar. If the cord length is not sufficient to reach the dewar, adjust the location of the helium compressor package or the dewar. 3) Connect the cables to the helium compressor by aligning them and then securing them to the panel using a small straight blade screw driver.
  • Page 63 Installation nitrogen generator and the dewar causing a significant drop in LN production. Over time, an accumulation of ice will completely block the flow of gaseous nitrogen into the dewar. The system will continue to operate however; it will not produce any LN CAUTION The compressed air filters are not designed to remove vaporous water.
  • Page 64 Installation The refrigerated air dryer must be installed and operated according to the manufacturer’s specifications included in the dryer’s instruction manual. Failure to follow the manufacturer’s instructions will void the warranty. Do not proceed further until the dryer manufacturer’s instruction manual has been completely read and understood.
  • Page 65 Installation 6.6 Air compressor installation The air compressor, if supplied by Cryomech, should be installed according to the manufacturer's specifications included in the air compressor's instruction manual. The manufacturer’s instruction manual is included with the air compressor. Proper installation and mounting of the air compressor is crucial to the safe operation and longevity of the equipment.
  • Page 66 Installation 6.6.4 Connect the air compressor to the main power CAUTION A voltage deviation of more than 10% above or below the voltage rating can cause motor overheating and possible failure. Indications of operation outside that voltage range will void the compressor warranty. 1) The air compressor MUST be connected to a dedicated circuit breaker.
  • Page 67 3) If the rotation is correct proceed to the next section. 4) Single Phase Air Compressors Only: If the rotation is incorrect, contact Cryomech. 5) Briefly energize the dedicated circuit breaker to bump start the motor. The motor should now turn in the correct direction.
  • Page 68 50 ft (15 m) roll of 3/8” OD copper tubing supplied with the air compressor. To aid in the cooling of the compressed air and condensing the moisture entrained in it, Cryomech recommends using the entire length of copper tubing to connect the air compressor to the N generator/filter bank panel.
  • Page 69 Installation Tapered end of ferrule in the direction of the fitting Fitting Ferrule Figure 6-5: Nut and ferrule properly installed on copper tube 5) Insert the copper tube into the fitting approximately 3/8 in (10 mm). Make certain the end of the tube is seated fully in the fitting. 6) Tighten the nut by hand until snug.
  • Page 70 It is fitted with a power cord that attaches to the front panel of the helium compressor package. Make certain the power cord is long enough to reach the front panel receptacle on the helium compressor package. Please contact Cryomech if a longer power cord is required.
  • Page 71 Installation Electrical Protection Receptacle Figure 6-7: Electrical protection receptacle (representative view) Push the plug onto the connector and turn the locking ring clockwise until snug. To disconnect the plug, reverse the procedure. The system will not start if the EPD is not connected to the helium compressor.
  • Page 72 Section 7 Operation 7.1-N...
  • Page 73 Operation Section 7: Operation 7.1 Starting the refrigerated air dryer (option) If the optional refrigerated air dryer is not supplied with the system, proceed to the next section. Before starting the dryer, make certain the installation was carried out according to the instructions given in this manual and the manufacturer’s manual.
  • Page 74 Operation 6) Check the receiver/tank pressure gauge for a steady increase in pressure. The pressure switch, which is preset at the factory, will shut the compressor off automatically. If inadequate air pressure or air pressure greater than 150 PSIG (10.3 bar) conditions exist, refer to the air compressor manual’s Troubleshooting section.
  • Page 75 Operation 7.4 Starting the helium compressor With the installation and dewar purge procedure complete, make the following checks before starting the helium compressor. 7.4.1 Checks before operating 1) Check the system pressure - the gauges should read the pressure specified in Section 5.
  • Page 76 6) If the flex lines are oriented correctly, contact Cryomech. 7.5 Normal operation behavior On initial start up, with the entire system at room temperature, normal helium compressor pressures are in the range of 70 to 85 PSIG (4.8 to 5.9 bar) on the low pressure gauge...
  • Page 77 Operation Within a few minutes of start up, a significant temperature difference should be noticeable between the high and low pressure Aeroquips attached to the cold head. The high pressure Aeroquip should be close to room temperature while the low pressure Aeroquip, along with the motor assembly of the cold head, will be much warmer.
  • Page 78 Operation 7.6 Extracting liquid nitrogen WARNING Before extracting liquid nitrogen from the dewar, carefully read the following safety precautions. Improper handling of liquid nitrogen may result in serious injury or death.  Transferring and handling liquid nitrogen can be extremely hazardous if the proper precautions are not taken.
  • Page 79 Operation WARNING The operator should be outfitted with the recommended personal protective equipment outlined above before extracting liquid nitrogen. Remove liquid nitrogen by opening the valve on the extraction line. When the valve is first opened, escaping gas will be heard and a white colored vapor will be seen exiting the end of the extraction line.
  • Page 80 If the dewar pressure gauge shows a pressure greater than 15 PSIG, disconnect the nitrogen flex line from the low pressure regulator and relieve the pressure through the bleed valve. The problem must be diagnosed and corrected immediately. Contact Cryomech if the cause of the over-pressurization is not determined.
  • Page 81 To shut down the air compressor, switch its dedicated circuit breaker off. 7.9 Disassembling the system for transport or storage Use the following steps to prepare a Cryomech Liquid Nitrogen Plant for eventual transport or storage. Assure that all components are stored in appropriate containers and location.
  • Page 82 Operation until they are released from the FPT fittings. Store the connectors for transport or storage. 8) (Water-cooled models only) Drain the water from the helium compressor. Blow remaining water out with compressed air. 7.9.2 Helium flex lines 1) Using the wrenches supplied in the tool kit, disconnect the high and low pressure flex lines from the helium compressor package by turning the Aeroquips...
  • Page 83 Operation Hold this wrench to prevent the cold head’s Aeroquip from loosening. Turn this wrench Figure 7-6: Disconnecting flex lines from a cold head 3) Install the dust plugs (that originally came with the system and are stored in the tool kit) on the female Aeroquip...
  • Page 84 Operation 7.9.5 Refrigerated air dryer (option) 1) Turn the power switch off. 2) Disconnect the cord from the power source. Coil up the power cord in preparation for transport or storage. 3) Disconnect the copper tubing from the inlet and outlet ports. 4) If applicable, disconnect the drain line from the condensate drain tube.
  • Page 85 Operation 7.10 Troubleshooting 7.10.1 Helium compressor will not start Helium compressor will not start. SYMPTOM POSSIBLE 1) No power supplied to the helium compressor. CAUSE 2) Circuit breaker off. 3) Power switch depressed with dewar cord unplugged. 4) Pressure switch tripped. 5) Temperature switch tripped.
  • Page 86 Operation 7.10.2 Helium compressor starts, no pressure fluctuation SYMPTOM Helium compressor starts, no fluctuation in the pressure gauges, no tapping sound from the cold head. POSSIBLE 1) Cold head motor cord not connected to the cold head. CAUSE 2) Aeroquip connector(s) not completely tightened. 3) High and low pressure helium flex lines reversed.
  • Page 87 Operation 7.10.4 Air compressor will not start SYMPTOM Air compressor will not start. POSSIBLE 1) Circuit breaker tripped. CAUSE 2) Interruption of the power supply to the air compressor. 3) Motor overload switch tripped. REMEDY 1) Reset the circuit breaker. 2) Check the power supply to the system and verify that it meets the requirements outlined in Section 5.
  • Page 88 Operation 7.10.6 No power to the electrical protection device SYMPTOM Yellow light not illuminated. POSSIBLE 1) Electrical protection device power cord not attached to helium compressor. CAUSE 2) Electrical protection device fuse blown. 3) No power supplied to the helium compressor. REMEDY 1) Attach the electrical protection device power cord to the receptacle on the front panel of the helium compressor.
  • Page 89 Once the Dewar is warm (room temperature) it should be re- purged for a minimum of 4 hours before restarting. 7.11 Contact Cryomech with Questions It is hoped that the Operation Section of this manual has helped you to obtain satisfactory results in the use of your Liquid Nitrogen Plant.
  • Page 90 Operation 7-18...
  • Page 91 Section 8 Routine Maintenance 8.1-N...
  • Page 92 Please adhere strictly to the maintenance schedule of the entire system. Cryomech recommends keeping a detailed maintenance log. For more detailed information please contact Cryomech.
  • Page 93 Routine Maintenance 8.3 Cold head CAUTION Service to the cold head must be performed using Cryomech parts and the appropriate work instruction. CONTACT CRYOMECH IF THE COLD HEAD NEEDS SERVICING. 8.4 Helium compressor adsorber replacement Required tools - CP800 Series Compressors...
  • Page 94 6) Loosen and disconnect the hose clamp that attaches the adsorber to the front panel. 7) Remove the adsorber from the compressor package. 8) Check the Aeroquip couplings for oil residue. If oil is present, contact Cryomech for further assistance.
  • Page 95 Routine Maintenance This procedure should only be used to vent small quantities of helium from an overcharged system. 1) Make sure the service valve is closed. See Figure 8-2. 2) Attach the small service Aeroquip coupling to the service access port. 3) Open the service valve slowly.
  • Page 96 Routine Maintenance Service Valve Service Aeroquip Coupling Charging line Figure 8-2: Service valve and access port 6) Attach a charging line from the service Aeroquip to a typical vacuum/charging system as shown in Figure 8-3 and Figure 8-4 below. Helium Tank Valve High Pressure Regulator Vacuum Helium Line...
  • Page 97 Routine Maintenance Line to Helium Vent Valve Tank Vacuum Sending Unit Relief Valve Vacuum Valve Charging Lines Service Aeroquips Figure 8-4: Close up of vacuum/charging manifold and pump 7) Evacuate to 50 microns. 8) Isolate the vacuum pump and add 50 PSIG (3.4 bar) of helium. 9) Vent the helium and repeat steps 7 &...
  • Page 98 Routine Maintenance 8.7 Clean air filter (CP2800 air cooled compressors only) It is recommended that the filters are cleaned every 90 days but it is dependent on the type of environment that the equipment is subject to. 1) Lightly soiled - Blow with compressed air - point compressed air nozzle in the opposite direction of the operating air flow (blow from exhaust side towards intake side).
  • Page 99 Wipe the mating surfaces of the coupling with a dry, lint-free cloth. • After wiping, blow off the coupling with clean, dry compressed air. • Solvents should never be used. • If any grease or oil gets on the Aeroquip coupling, contact Cryomech.
  • Page 100 Routine Maintenance 8.10 Replaceable fuses 8.10.1 Dewar level controller (LNP240 only) See the Fuse Specifications table in Section 5 for the ratings and characteristics of all replaceable fuses in the helium compressor. Qualified service personnel only should replace the fuses. 8.10.2 Electrical protection device (option) 1) Open the enclosure door to visually inspect the fuse covers.
  • Page 101 Helium flex lines The helium flex lines must be handled with care. If they become damaged and need to be replaced, new ones must be obtained from Cryomech and installed using the directions in the installation section of this manual.
  • Page 102 Appendix Spray Lubricant Instructions...
  • Page 103 Failure to follow these instructions will cause performance degradation and will void the warranty on your system. The purpose of this work instruction is to document the proper use of TFL-50® Dry Lube on Cryomech systems with Aeroquip® connectors. Related documents and work instructions: TFL-50® MSDS Connection, Installation 1.
  • Page 104 Appendix b. Make certain the flat gasket is properly seated in the male Aeroquip®. Flat Gasket Figure A-2: Cleaning the male Aeroquip® 2. Thread the female Aeroquip® onto the male by hand, until tight. Figure A-3: Female to male connection, hand tightened CAUTION Never apply lubricant to the open ends of the Aeroquips®.
  • Page 105 Appendix Figure A-4: Typical amount of lubricant 4. Apply a small amount of TFL-50® to the swivel portion of the female Aeroquip®. Swivel portion Figure A-5: Apply lubricant to swivel portion 5. Apply a small amount of TFL-50® to the threaded portion of the male Aeroquip®. Threaded portion Figure A-6: Apply lubricant to threaded portion 6.
  • Page 106 Appendix Disassembly 1. Apply a small amount of TFL-50® to the swivel portion of the female Aeroquip® as shown in Figure A-5. 2. Use wrenches to loosen and remove the Aeroquips® (see manual for instructions). 30Jan07...