Sigma 3-16PK - Service Manual

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CONTROLLED COPY

Centre for Biological Engineering

Standard Operating Procedure SOP122

Title: Use and Maintenance of Sigma Refrigerated Centrifuge 3-16PK

Location: CBE Laboratory Unit (H21/22)

Version 003 Effective Date: 26

June 2018 Review 26

June 2020

Written by: Victoria Workman

Reviewed by: P.Hourd

Approved by: R/I.Temple

Page 1 of 22

1PURPOSE

To describe procedures for the safe operation and maintenance of the bench standing Sigma 3-16PK

refrigerated centrifuge.

2 SCOPE

This SOP applies to the use and maintenance of Sigma 3-16PK centrifuge by authorised CBE

personnel within CBE laboratories. The centrifuge is used for separating substances or mixtures with a

density of up to max 1.2g/cm

. The SOP covers the use of the centrifuge using the following

designated rotors; swing-out rotor for sealable buckets (Cat.-No. 11180) and swing-out rotor for plate

centrifugation (Cat.-No. 11222). This SOP does not cover the use of any other type of rotor with this

centrifuge. Certified and hermetically sealed accessories (e.g. rotors, buckets or safety cups) MUST be

used for applications involving the centrifugation of infectious, toxic or pathogenic material

SPECIAL NOTES: HEALTH & SAFETY

2.1 Hazards associated with use of centrifuge

• Mechanical failure of rotating parts (often violent).

• Contact with rotating parts.

• Sample leaks causing aerosols, stress corrosion, contamination.

• Sample imbalance causing machine movement/walking.

• Fire/explosion.

• Contact with contaminated components/vapours.

2.2 Safe Working Practices (also refer to Safety Note in Operator Manual)

Users MUST read all Precautionary Statements in Section 2 of the Operators Manual and should

refer to the Guidelines in Annex 1 for further recommendations on the safe use of centrifuges.

(i) Ensure that the centrifuge is placed on a horizontal level surface and there is a clearance of at

least 30 cm around the centrifuge when in operation. Make sure that hazardous materials are

not stored or placed within this area and there is sufficient ventilation.

(ii) The centrifuge should not be placed in a safety cabinet unless an operator protection factor (KI

Discus) test has been carried out with it running in situ and it shown not to compromise operator

protection.

(iii) Always observe the start-up checks detailed in this SOP before using the centrifuge

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The Sigma 3-16PK refrigerated centrifuge is a bench-standing laboratory instrument designed for separating substances or mixtures with a density of up to 1.2 g/cm³. It is primarily used in biological engineering laboratories for various centrifugation applications.

Function Description

The centrifuge operates by spinning samples at high speeds, generating centrifugal force that separates components based on their density. It features refrigeration capabilities, allowing for temperature-controlled centrifugation, which is crucial for sensitive biological samples. The device is equipped with an automatic rotor identification system that performs a check after startup, ensuring the correct rotor is installed and adjusting pre-selected speeds if necessary. This system enhances safety and operational accuracy.

Important Technical Specifications

Model: Sigma 3-16PK refrigerated centrifuge
Serial Number: 137665
Maximum Sample Density: 1.2 g/cm³
Temperature Range: -10 °C to +40 °C (preselectable)
Rotors Supported:
- Swing-out rotor (Cat.-No. 11180):
  - Maximum load: 1100g per bucket (four buckets total)
  - Maximum speed: 4700 rpm
- Plate rotor (Cat.-No. 11222):
  - Maximum load: 600g per plate holder (three plates per holder)
  - Maximum speed: 3000 rpm
Centrifuge Tubes: Corning plug seal cap, sterile, polypropylene, non-pyrogenic, RCF: 9400xg, max 50mL (Fisher, CFT-643-021J).
Cleaning Agents: 70% IMS (for cleaning), 2% Detergent solution (Neutracon).

Usage Features

The centrifuge offers a user-friendly interface with a display for various program options and settings:

Display Fields: Time, "Lock" symbol (for lockdown), Temperature, Rotor selection, Imbalance indication, Run mode, Program selection, Speed, and RCF (Relative Centrifugal Force).
Rotary Knobs: Used for setting parameters such as rotor number, time, speed, and RCF.
Start Key: Initiates a centrifugation run.
Stop Key: Stops the centrifugation run.
Lid Key: Opens the centrifuge lid.

Setting Parameters:

Rotor Setting: The desired rotor number is selected using the rotary knobs. The system automatically identifies the installed rotor and corrects speed settings if a different rotor is detected.
Time Setting: Centrifugation duration can be set in minutes and seconds, or hours and minutes. Fine adjustments (1-second or 1-minute steps) are possible by holding the stop key during adjustment. Runtime can be changed while the centrifuge is running.
Speed Setting: The desired speed (in rpm) is set using the rotary knobs. The display indicates when the maximum permissible speed for the rotor is reached. Speed can be adjusted during a run. Fine adjustments (1 rpm steps) are possible by holding the stop key during adjustment.
RCF Setting: The desired RCF value (in x g) is set using the rotary knobs. The display indicates when the maximum permissible RCF for the rotor is reached. RCF can be adjusted during a run. Fine adjustments (1 x g steps) are possible by holding the stop key during adjustment.
Temperature Setting: Temperatures between -10 °C and +40 °C can be preselected in 1 °C steps. The temperature scale on the display shows the actual temperature in the rotor chamber and indicates if the set temperature is above, below, or identical to the actual temperature.
Rapid Cooling Facility (PrC): This feature allows for quick pre-cooling of the centrifuge. It runs at 1/3 of the maximum rotor speed continuously until the set temperature is reached, then reloads the previously set program. This helps prevent distortion of measurement results and increased wear of mechanical components.

Rotor and Sample Loading:

Rotor Insertion: The rotor is placed straight down onto the motor shaft and secured with a tie-down screw using a rotor wrench. It is recommended to remove and re-insert the rotor daily or after approximately 20 cycles to ensure a proper connection.
Swing-out Rotor (11180):
- Accommodates four buckets, each with a maximum load of 1100g.
- Samples must be distributed symmetrically, ensuring opposing buckets carry identical loads and are filled with liquids of similar density. A maximum difference of 100g between adjacent buckets is allowed.
- Buckets are placed correctly on the trunnions at a slight angle, pointing towards the middle. All four buckets must always be inserted for correct operation.
Plate Holder Rotor (11222):
- Each holder takes a maximum of three plates, up to a total of 600g.
- Plates must be diametrically (diagonally) balanced, not mirror images.
- Both holders must always be used and correctly inserted into the trunnions.
Sample Container Handling: Sample containers should only be filled within the manufacturer's recommended range and never when mounted in the centrifuge (unless specifically designed for this). Overfilling tubes or bottles should be avoided. Only correct designated tubes should be used, and glass containers are strictly prohibited.

Safety Precautions:

Placement: The centrifuge must be placed on a horizontal, level surface with at least 30 cm clearance around it for ventilation. Hazardous materials should not be stored in this area.
Rotor Integrity: Only manufacturer-specified rotors and accessories should be used. Damaged rotors, buckets, or tubes (cracks, nicks, corrosion, discolouration) must not be used and should be reported. Rotors and accessories have a limited lifetime (e.g., rotors must be inspected after 10 years or 50,000 cycles).
Balancing: Proper load distribution and balancing of samples are critical to prevent machine movement, increased wear on bearings, and potential mechanical failure.
Hazardous Materials: Toxic, pathogenic, or radioactive materials must only be centrifuged with proper aerosol containment (e.g., sealed containers, sealed buckets). Flammable or explosive vapours must not be centrifuged.
Operation: Never attempt to slow the rotor by hand. Do not open the lid until the rotor has completely stopped. Stay at the centrifuge until it runs smoothly and shut it down immediately if unusual noise or vibration occurs.
Spills: Any spills must be cleaned immediately.

Maintenance Features

The centrifuge requires regular maintenance to ensure safe and efficient operation.

Pre-run Checks: Before each use, all safety-relevant parts (rotor, accessories, cover seal, adapters, tie-down screw) must be inspected for cleanliness, damage, wear, abrasion, or discolouration. Buckets and centrifuge tubes should also be checked. Any signs of damage require immediate consultation with the Responsible Person and recording the inspection outcome.
Rotor Care:
- Rotors must be kept clean and dry after use to prevent corrosion. Washing with mild detergent and warm water using a nylon bottle brush is recommended, followed by thorough drying. Rotors should be stored upside down with the cover and tubes removed.
- Aluminium rotor components should not be exposed to strong acids, bases, alkaline lab detergents, or heavy metal salts to avoid corrosion.
- The centrifuge chamber, drive spindle, and tapered mounting surface of the rotor must be clean and free of scratches or burrs.
- The rotor tie-down nut must be secure, and the rotor properly seated on the drive hub.
- If the chamber temperature is below room temperature, pre-cool the rotor to minimize seizing to the spindle.
- The centrifuge undergoes a service every 2 years, with reports filed in the equipment file.
Tube Care: Tubes should be checked for cracks before use. The inside of cups should be inspected for rough walls and adhering matter. Tubes must be properly balanced and not filled above the manufacturer's recommended maximum. Compatibility of tube material with the solvent medium should be checked.
Routine Checks (Monthly):
- The housekeeper is responsible for monthly inspections of all safety-relevant parts for damage, wear, or discolouration. Damaged parts must be replaced immediately.
- The concentricity of the motor shaft should be visually inspected by slowly rotating the rotor by hand. If the shaft does not turn on a perpendicular axis, the motor and shaft must be replaced.
- The unit should be checked for atypical running noises.
- All screw connections must be tight.
- All inspection outcomes are recorded in the Preventative Maintenance of Centrifuges Record.
Centrifuge Cleaning (Daily/Monthly):
- Any liquid spills must be removed immediately.
- After each day's use, the inside of the centrifuge chamber, all rotation assembly parts, and head accessories must be cleaned and dried. Inserts and adaptors should be removed for adequate cleaning and drying.
- Monthly cleaning involves wiping the centrifuge casing, venting slots, rotor chamber, rotor, and accessories with mild (pH 6-8) detergent. Organic solvents must not contact the drive shaft or ball bearing, as they can decompose lubricant.
- After cleaning, holders should be dried with tissue, and a small amount of grease applied to the load-bearing bolts of the rotor and buckets.
- All cleaning events are recorded in the Preventative Maintenance of Centrifuges Record.
Sterilization and Disinfection:
- In case of spills or leaks, the centrifuge must be disinfected immediately, following risk assessment procedures.
- Rotors can be autoclaved, but not more than 10 times. The Operator's Manual should be consulted for material resistance and recommended sterilization cycles.
- After autoclaving, all safety-relevant parts must be checked for damage, wear, or leaks.
- For glass breakage, all glass particles must be carefully removed. Rubber inserts should be cleaned or replaced. To remove glass and metal dust from the rotor chamber, grease the upper part of the chamber, rotate the rotor at moderate speed for 5 minutes, and then wipe away the grease with a cloth.
Malfunction/Faults: If any part fails or malfunctions (vibration, noise, failure to operate), the user must contact the Laboratory Manager/Responsible Person. The centrifuge should be tagged and locked-out ("Do Not Use" notice) while awaiting service. External maintenance requires prior disinfection and a 'Decontamination Certificate'.
Decommissioning: If the centrifuge or rotor needs to be decommissioned, a checklist must be completed to ensure no hazardous materials remain and the unit is decontaminated. This checklist is forwarded to the DSO or responsible person for disposal.