Pressure Vessel Operating Conditions

The central component of the Nova 8800 is a pressure vessel designed to accommodate pressures of more than 2,000 psi.  During normal conditions, the unit will operate at pressures between 1,400 and 1,500 psi and a temperature of approximately 95°F.  The vessel is designed, constructed and certified to the applicable codes of the American Society of Mechanical Engineers (ASME).  Certification documentation is available from NovaSterilis upon request.

The working pressure and temperature in these sterilizers should not exceed 1900 psi and 200°F. 

 

Specs of Pressure Vessel

The Pressure Vessel, Vessel Head and Retaining Rings are manufactured in accordance with ASME code requirements and can be safely used at temperatures and pressures discussed elsewhere in this manual.  The Pressure Vessel and Vessel Head are manufactured from 316 Stainless Steel.  The Pressure Vessel has an inside diameter of 16 inches and a depth of 28.25 inches.  The vessel volume is approximately 20.8 US gallons (78.8 L) or approximately 5,403 cubic inches.  The Retaining Rings are a plated steel alloy and split in 2 symmetrical halves.  The combined weight of these components is approximately 1837 pounds. The Vessel Head Seal is specifically designed to accommodate the pressures and chemicals used in the sterilization process.  It has been designed to accommodate hundreds of leak proof operations.

 

Stirring System

The stirring system is programmed to check for correct stirring speed and proper engagement of the stirrer.  The system is designed to automatically attempt to re-engage the stirrer in the event it senses disengagement.  If the system cannot automatically re-engage the stirrer, the system will provide visual notification on the touch screen monitor and a printed error message. The stirrer is programmed to operate at speeds between 620 RPM and 720 RPM.

 

Temperature Monitoring

Vessel temperature is monitored using a Type J thermocouple penetrating the vessel through a 1/8" diameter threaded opening in the bottom of the vessel.  The detector is sealed in a 1/8” stainless steel sheath and is connected to the thermocouple socket at the controller using an extension wire.  The current temperature is displayed on the touch screen monitor whenever the system power is on.  Heaters are installed to maintain temperature as measured by the unit’s thermocouple at the desired operational temperature during operation.  The heaters are programmed to avoid operation below approximately 10°C and can operate in the full on, full off or percent on modes.  The instrument accuracy of the temperature monitoring system is approximately +/- 2° Celsius and the system has been designed to accommodate this tolerance.

 

Pressure Monitoring

Vessel pressure is monitored using input from 2 redundant pressure sensors to ensure the validity of the reading.  The pressure sensors are piped on the vessel side of the CO2 inlet piping.  The current vessel pressure is displayed on the touch screen monitor whenever the system is power is on.  The pressure monitoring system is accurate to better than 1% of expected operating range.

 

Computer Information

The unit employs a single board computer equipped with 256 MB of RAM and hard disk storage for embedded software and data for several thousand runs.  The board provides connections for the following standard and optional peripheral equipment:

 

Standard:

·         LCD Touch Panel Monitor (connected via 15 pin and 9 Pin D-SUB connectors).  See Touch Screen Monitor Section for operating instructions.

·         Printer (connected via a DB 25 pin connector)

·         Barcode Scanner (connected via DB 9 pin connector)

Optional:

·         PC Keyboard (standard keyboard / PS/2 mouse connector)

·         Network connections (RJ 45 connector)

 

Optimal Ambient Conditions

The unit is designed to be installed indoors in a well ventilated area.  Ambient air conditions should remain between 59 to 86°F (15 to 30°C) and relative humidity not expected to exceed 80% (non-condensing). Acceptable geographic altitudes are from 0 to 6,550 feet (0 to 2000 meters).

 

Dimensions

 

NOVA 8800*

Buffer Space

Total Space

Height

72”

6”

78”

Width

55”

24” each side

79”

Depth

41”

> 36” from wall

77”

 

The installed unit weighs approximately 2,200 pounds.  The weight is distributed over 4 legs and wheels.

Nova8800 Drawing
Nova8800 Drawing

 

Electrical Service Requirements

The Nova 8800 is manufactured with plugs for standard receptacles for the following circuits:

 

·         One (1) - 120 volt, 60 Hz, Minimum 15A circuit

·         One (1) - 240 volt, 60 Hz, Minimum 50A circuit

 

Pneumatic System Supply Requirements

Compressed air is used to operate the pneumatic system.  Compressed nitrogen may be substituted if necessary.  The source should be filtered and the filter should be located immediately upstream of the unit.  The source shall not exceed 120 psi @ 15 SCFM and shall be regulated to 85psi.  Air supply piping should be:

 

·         ½ “ stainless steel (copper piping may be used per applicable local code requirements); OR

·         ½ ” flexible tubing (polyethylene, polyurethane, or nylon) with pressure rating >150 psi

 

Carbon Dioxide Supply

The CO2 supply enters the unit through the port labeled “CO2 IN” (½” Swagelok® Bulkhead fitting).  A reliable source of carbon dioxide is critical for proper operation of the Nova 8800.  NovaSterilis support services are available to arrange for CO2 supply.  Temperatures for CO2 storage should be such that the CO2 remains in a liquid state.  Tanks shall be of the siphon type (equipped with a dip tube) to remove liquid CO2 from the bottom of the cylinder.  The preferred CO2 source configuration as follows:

 

·       Cylinders: Two (2) banks of four (4) - 75 pound CO2 siphon cylinders.  1-CGA 320 fitting (UN1013, Class 2.2) per CO2 bottle with 1/4" NPT fitting

·       Gas: Medical Grade (99.9% purity) or better

·       Piping: 1/2" SS pipe/tube .035 tube wall (booster to vessel and vessel to exhaust)

 

The Vessel volume is slightly less than 80 liters.  Each run will require approximately 135 pounds of CO2.  When installed in banks, each bank of cylinders shall be isolatable and connected to a common manifold.  NovaSterilis can construct and install an appropriate manifold upon request.  Alternative CO2 supply configurations should be reviewed with NovaSterilis prior to implementation.

 

As delivered, the unit will exhaust through the “CO2 OUT” port via a ½” Swagelok® bulkhead fitting.  The customer’s facility shall install a means to adequately vent the CO2.  Never attempt to operate the unit without adequate CO2 exhaust venting.

 

Preventive Maintenance

Preventive Maintenance should be performed by an authorized NovaSterilis service technician under a NovaSterilis factory service contract (details available upon request). The following tasks are performed during routine maintenance:

  • Pressure Relief Valve refurbishment and calibration
  • Stirring system cleaning, refurbishment, and checkout. Outlet valve condition check and timing
  • Vibration check and component tightening
  • Instrument calibration