Bulk Steam Sterilizers

STEELCO floor loading range steam sterilizers VS L series are designed for laboratory applications including research laboratories, biocontainment and animal care facilities.

VS L sterilizers are engineered to offer best in class solutions for the reduction of energy and water consumption to give users lowest operating costs per load, ECO water saving packages reduce water consumption to nearly zero depending on chosen model and options.

All Steelco steam sterilizers VS L range are equipped with high quality AISI 316L stainless steel pressure vessels. Pressure vessels are full jacket doublewall design and chamber cross section is rectangular with 4 standard chamber sizes.

Sterilizers are available in single or double horizontal sliding door configuration. Doors are automatically actuated.

Steeclo VS L sterilizers are controlled by commonly available industrial grade PLC digital controllers with color touch screen HMI.

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STEELCO manufactures according the ISO 9001 quality system. Steam sterilizers VS L series meet the following standard requirements:
UL/CSA Standards
ASME (section VIII div.1, Section I)


material and construction
Pressure vessel is made of AISI 316L solid stainless steel plate Ra < 0,315μ inch in finish. Pressure vessels chamber cross section is rectangular and full jacket double-wall design made of stainless steel AISI 316L.

The external insulation of the vessel is realized with non-toxic fiber. The covering reduces heat emission and noise level. Covering can be easily removed for maintenance operations.

Service access panels / Control panel and technical room
Piping, valves, electrical components and wiring are easily accessible from panel or side access.

Door system
Doors are made of stainless steel AISI 316L, with no welding and are be automatically actuated.
Automatic sliding doors are activated by a motorized endless screw system. A high sensibility safety bumper guarantees the safety of the operator.
Door locking is automatically actuated.
The perimetral silicone seal is pushed against the door by compressed air if available and/or the sterilizer is equipped with pneumatic valves.

RTD (Resistance Temperature Detectors) temperature probes
A dual element PT1000 temperature probe is installed in the drain of the chamber to allow the precise control of temperature variations within the chamber. Jacket RTD provides temperature control within the chamber jacket. An additional load control probe is provided as standard forload temperature monitoring throughout the entire cycle.

Steam supply systems
Standard steam supply: Steam from building (type “V”)
Optional steam supply:
* Integral electric steam generator (type “E”) made of carbon steel or AISI 316L stainless steel
* Integral steam-to-steam AISI 316L generator for clean steam application (type “I”)

STEELCO steam sterilizers VS L series are equipped with a Safety Lock which prevents the operator from starting a program before the door is fully closed. The door is mechanically locked during the whole cycle and cannot be opened until the cycle has completed and until pressure and temperature in the chamber are normalized. A main power ON/OFF switch is located on the electrical box.

Emergency Stop Button for power door sterilizers is located on the front panel, below the sterilizer control touch pad. When pressed, immediately shuts off all outputs on the sterilizer. A key is used to reset the switch. This is an option for power-door equipped sterilizers only.
Control Lockout Switch equipped on chamber door(s), senses when door seal is energized and tight against the door. Control prevents cycle from starting until the limit switch signal is received. If control loses appropriate signal during cycle, alarm activates, cycle aborts and chamber safely vents with a controlled exhaust.
– Pressure Relief Valve limits the amount of pressure buildup so that the rated pressure in the vessel is not exceeded.
– Power Door Safety Feature causes door driveto slip if the sliding door encounters an obstruction during its movement.

Water saving packages for a better environmental performance of autoclaves equipped with either water ejector or water ring vacuum pump vacuum systems.

– ECO CD – cool down system
The system consists of a tank that collects both chamber and condensate drains. Temperature within the tank is controlled by a thermostatic valve and drain temperature is kept below 140°F prior to discharge by adding cold water from building.

– ECO EVO system
The system consists of a tank that collects both chamber and condensate drains. Collected water is re-circulated to feed vacuum systems. Water temperature within the tank is controlled by a thermostatic valve by adding cold water from building. Added water is triggered according to vacuum systems need, drain temperature is kept below 140°F prior to discharge.

– ECO EVO PLUS – system
The system consists of a water tank that collects both chamber and condensate drains. Collected water is re-circulated to feed vacuum systems. Water temperature within the tank is controlled by a thermostatic valve and the system exchanges heat with a chilled water loop from building. Water is added mainly for system start up and water consumption is reduced to nearly zero. Drain temperature is kept below 140°F prior to discharge.

ADVISORY NOTE: ECO options as well as other options may not be available for all models and subject to overall dimensions changes of the equipment. Water saving vary in relation to the autoclave chamber size and utilities.

PLC based control system: the control system consists of an industrial PLC (Allen & Bradley) with a color touchscreen panel with Input/ Output modules and a printer. The PLC includes an Ethernet port to connect the sterilizer to a system of traceability and process control that can also handle multiple machines and allows to print the report cycle in paper format. The control system is equipped with a color touch screen HMI installed on the loading side of the sterilizer, an additional HMI panel is installed on the unloading side on a pass through configuration to allow the operator to check the status of the sterilizer.

As an option, a second HMI panel providing full functionality of the system can be installed on the unloading side on the double door version.

Up to 50 cycles available with standard cycles and testing/maintenance cycles.

User access:
The operator can access the normal use of the sterilizer by logging in. Access to the configuration of the machine is protected by 3 levels of password:
1) Supervisor: this level grants an access to the basic functions (recording and setting) of the equipment: date, time, operators list, cycles reprint…
2) Maintenance Technician: this level allows the same functionalities as “Supervisor level” but also grants the possibility to modify the parameters of the customizable cycles and a more complete access to the machine parameters.
3) STEELCO Service: this level grants a full control of the equipment and the possibility to edit the factory cycles

Software calibration of the parameters
Software calibration of the pressure and temperature parameters can be performed through the touch screen display by a qualified technician with the control panel in the Service Mode.

Control system provides printed record of all calibration data for verification to current readings.

Thanks to our user friendly operator interface the dedicated screens permit the maintenance people to access the functions of calibration and verification of the components operation status
The dedicated screens permit the supervisors responsible for the maintenance to easily set up the machine.
During the cycle, the temperature and the pressure values are recorded at set time intervals.
Printout of the cycle report. At the end of the cycle, the printer prints a report of the cycle.

Vacuum Leak Test
This standard cycle is used to verify the vacuum integrity of the sterilizer. While running this cycle, the sterilizer chamber must be empty.
Max accepted leak rate; 0.013 bar / 10 min
Max accepted leak rate; 0.19 psi / 10 min
Max accepted leak rate; 1.3 kPa / 10 min

D.A.R.T. (Bowie Dick Test)
This standard cycle is used to verify the effectiveness of the steam penetration and air removal for the sterilizers provided with a vacuum pump.
Sterilization temperature: 275°F
Sterilization time: 3.5 Minutes
Drying time: 5 Minutes

Working programs are factory set and available for the operator selection in the control panel.

Cycles configuration:
Sterilizers are factory programmed with the cycles at 275°F and 250°F. The temperature inside the chamber is uniform in every part, and the temperature deviation is less than 32°F.

Cycle description
Once a program is started, the sterilizer automatically processes the load through a predefined combination of the standard phases below mentioned.
Conditioning – This phase is executed to reach the optimal conditions needed for a sterilization cycle as well as for a testing cycle. A series of pulses of vacuum and pressure with steam is generated inside the chamber. The last steam injection will bring both the chamber pressure and temperature at the sterilization values.
Sterilization – The temperature and the pressure of the chamber are maintained constant for the needed sterilization time
– Drying – The vacuum is continuously created into the chamber for a specified time; at the end, the atmospheric pressure is re-established. Additional cycles can be customized.

Programs included:
1) Gravity cycle
For the sterilization of heat- and moisturestable goods and decontamination of bagged non-biohazardous laboratory wastes. Gravity cycle utilizes the gravity air-displacement principle.
2) Pre vacuum – post vacuum cycle 275°F (Utensils, glassware, textiles)
For efficient, high-volume sterilization of porous, heat- and moisture-stable materials. Prevacuum cycle utilizes a mechanical air evacuation system.
3) Pre vacuum – post vacuum cycle 250°F (Plastic, rubber products and macrolon cages)
For efficient, high-volume sterilization of heat-sensitive materials. Prevacuum cycle utilizes a mechanical air evacuation system.
4) Liquid cycle 250°F (liquids in open or vented containers)
For the sterilization of liquids and media in vented borosilicate glass or metal containers. Liquid cycle utilizes the optimal solution cooling feature, during exhaust (cooling) phase, to control the exhaust rate.

Steam Autoclave mod. VS L, single or double door, floor or pit mounted
Automatic sliding door
Service room (technical area) on the right side or on the left side of the sterilizer
Frame and external panels made of AISI 304 stainless steel
– “V”: connection for steam from building
ASME stamped pressure vessel
ASME stamped pressure relief valves
Chamber made of AISI 316L stainless steel fine satin finishing (Ra < 0,315μ inch)
Degreasing and passivation of the chamber
Piping and valves in copper-brass
Stainless steel full jacket chamber
Solenoid valves
Chamber rails with shelves
Water ejector vacuum system
Water-saving system ECO CD with drain cooling system (T<140°F)
PLC control system
Electrical components UL compliant
Product RTD probe
Vacuum breaker filter DOP tested (filtration grade 99.999%, filter can be sterilized)
Thermal printer on loading side

PLC system
Siemens industrial PLC package
HMI full capability on unloading side

Service/control side (when applicable)
Right side service
Left side service

Chamber options
Chamber made of 316Ti stainless steel
Chamber polishing (Ra<0.5 μm)

Application of side and top panels for free standing versions

Steam source
Steam filter for direct steam feeding
“E”: integral electric steam generator
“I”: AISI 316L integral steam to steam generator

Process steam wetted piping of AISI 316L stainless steel
Valves and components of AISI 316L stainless steel

Vacuum system
Double stage water ring vacuum pump

Valve options
Pneumatic valves
Air compressor (compressed air necessary for pneumatic valves actuation)

ECO water saving options

Cycle options
– Jacket cooling cycle: this cycle, specific for porous loads, provides a rapid cooling by introducing cool softened water into the jacket
– Air over pressure with jacket cooling cycle: this cycle is specific for treating liquids in either sealed or vented rigid containers. It is designed for cooling liquids in vented containers where boiling and liquid loss need to be prevented or to prevent liquids in sealed rigid containers from rupturing. Cool softened water is introduced into the jacket and process compressed air (PCA) into the chamber – it prevents boiling of vented liquids and provides counter pressure for sealed liquids in rigid containers
Effluent decontamination cycle*: this cycle is used for processing contaminated items; condensates of the chamber are not discharged to prevent harmful pathogens and viruses from exiting the sterilizer during the exhaust and vacuum phases of the sterilization chamber and prior to sterilization time and temperature requirements are met. The drain is controlled by an hydrophobic 0.08μ inch filter and both filter and condensate are sterilized during the cycle.
Diaphragm Valves: these valves are indicated for demanding sanitary and high purity applications, as they prevent fluid from contacting the actuating components within the valve. They are standard in case of a decontamination cycle, while they can be ordered as option in case of porous load or liquid cycles*
In Situ air intake Filter Sterilization cycle: this additional factory pre-set program is used to sterilize the chamber air intake filter while it is in place. The program will automatically sterilize the filter with no user intervention. The hydraulic configuration comprehends additional valves, temperature probe and condensate drain system. This program is applicable with both the Disposable HEPA Filter and the Stainless steel HEPA Filter with disposable cartridge.
Low temperature cycle (Isothermal or F0): In this cycle the exposure length is based on a settable value for the total accumulation of F0 during the charge and exposure phases. The cycle is completed when accumulated F0 value is reached.
Disposable HEPA Filter / Stainless steel HEPA Filter with disposable cartridge: filters for vacuum brake with a predisposition for water intrusion test; can be sterilized in-situ

Containment options
Bio-Seal Frame
: this option is designed to hermetically seal the autoclave and prevent the cross contamination between contaminated and non-contaminated areas. It consists of stainless steel panels that are hermetically sealed by means of a special silicone on the autoclave body.

Process feature options
Pipework with sample points for testing clean steam quality
Thermocouple fitting (up to 16 thermocouples)

Control options
Free contacts (for critical alarms): these relay contacts (also called “dry contacts”) can be used to signal alarms or to provide information on the cycle status
Connection for remote monitoring (tele-service)

Uninterruptible Power Supply
UPS for a temporary power supply of the PLC control system

Seismic options
Seismic tie down kit
Seismic package

Validation and documentation options
IQ documentation
OQ documentation
FAT documentation
SAT site acceptance test

Water softener
It reduces the hardness of the water to be supplied to the steam generator

Loading shelves and racks, transport trolleys, automatic loading/unloading systems *
Loading shelf (AISI 316L)
Double level loading rack (AISI 316L)
Triple level loading rack (AISI 316L)
Fixed height transport trolley (AISI 304)
Adjustable height transport trolley (AISI 304)

*ADVISORY NOTE: These options and accessories may not be available for all models and may subject to overall dimensions changes on the equipment.

ModelInternal Chamber Dimensions External Chamber Dimensions
Single Door Models
VS 378686/1 L37 in (W)
86 in (H)
86 1/2 in (D)
102 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 498686/1 L26 in (W)
36 in (H)
86 1/2 in (D)
126 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 618686/1 L26 in (W)
36 in (H)
86 1/2 in (D)
150 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 728686/1 L26 in (W)
36 in (H)
86 1/2 in (D)
172 1/2 in (W)
109 in (H)
104 7/8 in (D)
Double Door Models
VS 378686/2 L37 in (W)
86 in (H)
86 1/2 in (D)
102 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 498686/2 L26 in (W)
36 in (H)
86 1/2 in (D)
126 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 618686/2 L26 in (W)
36 in (H)
86 1/2 in (D)
150 1/2 in (W)
109 in (H)
104 7/8 in (D)
VS 728686/2 L26 in (W)
36 in (H)
86 1/2 in (D)
172 1/2 in (W)
109 in (H)
104 7/8 in (D)