Safety Department
ImperialCollegeLondon
Sherfield Building
South Kensington Campus
LondonSW7 2AZ, UK
Tel: +44 (0)20 7594 9421
Fax: +44 (0)20 7594 9424
Guidance Note GN042
Maintenance, inspection and testing of pressure vessels in research laboratories
October 2007
This guidance note is primarily directed at Laboratory Managers, laboratory workers, Campus Managers, Building Managers, Maintenance Team Managers.
Pressure vessels which either contain steam at any pressure, or exert a pressure in excess of 0.5 bar above atmospheric pressure and contain gas or fluids (or some mixture of them), require maintenance in accordance with manufacturers’ instructions, testing to ensure that standards are met, and inspection to ensure that the vessel body, pipework and valves and parts are in good condition – similar to an MOT.
Pressure vessels include items such as pressure cookers, bench top sterilizers, autoclaves, steam generators, air compressors and some liquid nitrogen vessels. Items such as Estates plant (building-wide steam generators, boilers, compressed gas silos etc) are not included in the scope of this guidance.
This guidance note includes:
- Definitions of pressure vessels
- How to register a pressure vessel for insurance inspection
- Information on the record keeping requirements.
Table of Contents
1.Relevant Legislation
2.Responsibilities under College Health and Safety Policy
3.Definitions
4.Pressure vessels and systems
5.Maintenance and use in accordance with manufacturers’ instructions
6.Requirement to inspect and examine
7.Written scheme of examination (WSE)
8.Information required by the Insurance Inspector
9.Arranging an Insurance Inspection
10.Procedures for registration with Estates
11.Entry of non-authorised personnel into laboratories
12.Rented and second-hand vessels
13.Laboratory equipment which is integral with the building
14.Procedures for inspection and re-inspection after repair or modification
15.Failing an inspection - actions to be taken
16.Decommissioning and deregistering unwanted vessels
17.Testing autoclaves in accordance with specific regulations (GM, COSHH etc)
18.Annual update of personnel and equipment databases
19.Record keeping
20.Appendices
1.Relevant Legislation
a)The Health and Safety at Work, etc. Act 1974 requires employers to provide and maintain plant and systems of work that are safe and without risks to health.
b)The Pressure Systems Safety Regulations 2000 (PSSR)[1] aims to prevent serious injury from the hazard of stored energy as a result of the failures of a pressure system or one of its component parts. The contents are not considered in the same way as COSHH except where there is a risk of scalding or where the contents may speed up corrosion or degeneration of the vessel and its components.
c)The Provision and Use of Work Equipment Regulations 1998 aims to ensure that work equipment should not result in health and safety risks, regardless of its age, condition or origin.
2.Responsibilities under College Health and Safety Policy
As an employer, the College must ensure that its plant and machinery is safe and will not cause harm to any persons, including College staff, students and visitors (including representatives of manufacturers, suppliers, service organisations, external contractors and members of the public.
It is the responsibility of the Principal Investigator, Supervisor or other person in charge of the area to ensure that activities (including safe use and storage of equipment) under their direction do not jeopardise the College’s compliance with the law. In practice, this is often delegated to laboratory managers. Safe use of pressure vessels would include ensuring that suitable vessels are purchased, installed and commissioned by competent persons, registered with the Estates Helpdesk, used safely by trained persons, maintained in accordance with manufacturer’s instructions, and inspected in accordance with a Written Scheme of Examination drawn up by a Competent Person (the College Insurance Inspector).
Principals of Faculties and Heads of Department/ Division are accountable to the Rector for the proper implementation of all health and safety policies and procedures in their respective areas and compliance with College and statutory requirements.
Whilst certain practical duties and implementation of procedures may be delegated by Principal Investigators, Supervisors or Heads of Departments, final responsibility for ensuring that compliance is achieved remains with the Principal Investigator/Supervisor and Head of Department.
3.Definitions
Laboratory areas -for the purposes of this document, ‘laboratory areas’ include: research and diagnostic laboratories, laboratory equipment rooms, cold rooms, media preparation rooms, wash-up rooms, post-mortem rooms and greenhouses. It does not include other potentially hazardous areas that are under Estates control.
User -the College employee who: decides when installed plant will be turned on or off; who decides who has access to the plant; who is responsible for the controls of the plant; and who maintains and runs the plant on a day to day basis
Owner -the person who owns mobile or rented equipment which may be used by other persons such as College employees or College students
Competent person - is someone who is trained and experienced in a particular skill, and can recognise limitations of personal expertise. In the College this expertise has been contracted out to the College Insurance Inspector, who is supported by relevant specialist services and organisational arrangements, as required by the PSSR Approved Code of Practice.
Written scheme of examination – a WSE is drawn up by a College Insurance Inspector (unless this is already supplied from the installer/commissioner of the system) and lists the parts of a piece of equipment or plant (eg safety valves), and the frequency and thoroughness of inspection required for each part.
Relevant fluid - includes steam at any pressure or gas or fluids (or some mixture of them) at 0.5 bar above atmospheric pressure.
4.Pressure vessels and systems
A Pressure Vessel is a receptacle containing steam at any pressure, or exerting a pressure over 0.5 bar (7.5 psi) above atmospheric pressure and containing gas or fluids (or some mixture of them).
There are three types of Pressure System
i)A pressure vessel, its associated pipe work and protective devices.
ii)Pipe work with protective devices, eg safety valve and/or gas regulator, to which a transportable pressure receptacle may be connected
iii)A pipeline and it’s protective devices
There are three categories of Pressure System – in the laboratory environment, most will fall into the minor or intermediate systems. Examples may be found in Appendix 1 – Examples of pressure equipment.
Minor systems / Intermediate systems / Major systemsSmall, simple, systems containing steam, pressurised hot water, inert gases or fluorocarbon refrigerants. / Anything that does not fall into minor or major categories. / Steam generator over 10 MW
Pressure should be less than 20 bar (2.0 MPa) above atmospheric pressure unless the system has a direct-fired heat source, when it should be less than 2 bar (200kPa) / Pipelines are included if the pressure-volume product is greater than 105 bar litres / Any pressure storage system where largest vessel is more than 106 bar litres (100MPa m3)
Pressure-volume product for largest vessel should be less than 2x 105 bar litres (20 MPa m3). / Any manufacturing or chemical reaction system where the pressure-volume product for the largest vessel is more then 105 bar litres (10 MPa m3)
Temperatures in system should be between –20C to 250C / Pipelines are included if the pressure-volume product is greater than 105 bar litres
Smaller refrigeration systems operating at lower temperatures
Pipelines are not included
5.Maintenance and use in accordance with manufacturers’ instructions
Manufacturers and suppliers are required to specify servicing requirements to purchasers of machinery. This would include service periods for conditions of “normal use”. To ensure safe use, all machinery used in the work place, including pressure vessels must be serviced and maintained in accordance with the manufacturer’s recommendations.
The Department owning the vessel is responsible for establishing the equipment maintenance contract and meeting the cost of maintenance.
The Local Estates Representative should be contacted when a maintenance contract is being established or renewed – they may know of alternative suppliers offering more favourable terms or if a College-wide contract is in place. In any case, the local Estates representative will need to be made aware of service visits, as this can then be co-ordinated with insurance inspections when necessary, usually at time of thorough examination.
Equipment may require more frequent and more stringent servicing as well as additional control measures depending on its location and use. Advice should be sought from the manufacturer in this instance. See 8.Information required by the Insurance Inspector
6.Requirement to inspect and examine
If a pressure vessel or part of a pressurised system fails, the consequences could be severe (explosion, scalding etc). Therefore the User is responsible for ensuring that College-owned (including grant-funded) pressure systems are maintained, operated safely, and precautions taken to prevent over-pressurisation.
In addition, the User must ensure that a competent person (the College Insurance Inspector) makes a thorough annual inspection and regular examination of any College-owned pressure systems containing steam or having a pressure x volume equal to 250 bar litres or more.
The scope and frequency of the examination is defined in a Written Scheme of Examination, drawn up by the College Insurance Inspector. Usually a written scheme is produced as part of the commissioning process, but in any case will be provided by the Insurance Inspector on the first examination. The DecisionTree in Appendix 1 helps to determine the duty holders.
7.Written scheme of examination (WSE)
If the supplier has not provided documentary evidence on commissioning and testing, advice must be obtained from the College Insurance Inspector(s) on whether a WSE should be drawn up before first use of any relevant pressure equipment. The scope of the examination depends on the complexity of the equipment and the harm resulting in the event of failure.
The User must determine the scope of the WSE – if for example the equipment is likely to be weakened due to chemical or environmental conditions then pipe work should be included or if sudden failure of pipe work would give rise to danger. In practice, the College Insurance Inspector would do this on the User’s behalf provided he is supplied with certain information (see below).
The College Insurance Inspector sends the original WSE to the Estates Helpdesk, who in turn will send copies to the local Estates representative. The Insurance Inspector will notify any subsequent modifications to the WSE (after repair for example) to the Estates Helpdesk, who will notify to the local Estates Contact by means of an amended hard copy and an electronic version, which is then circulated as an update. Appendix 2 – Local Estates Contacts
8.Information required by the Insurance Inspector
To determine the depth and frequency of an examination, the Inspector will need to be informed of the use and environmental conditions that the equipment is subjected to, for example:
i)If environmental conditions are extreme, if corrosive chemicals such as acids or salts are used within the vessel or are present in the external atmosphere, then physical degradation of the equipment components is expected and the service frequency may need to be increased. Similar consideration must be given to extremes of temperature, moisture, dust, etc.
ii)If domestic-type equipment is being used for research purposes (as this would not be considered to be normal use by the manufacturer or supplier). Note that domestic pressure cookers must not be used for laboratory-type work within the College.
The User should note under such circumstances, maintenance and servicing periods may need to be more frequent then those specified by the manufacturer. See 5. Maintenance and use in accordance with manufacturers’ instructions
9.Arranging an Insurance Inspection
This should coincide with annual maintenance, as the machine may need to be stripped down for the Inspector to access its workings. To ensure that maintenance coincides with inspection, two actions are necessary.
i)Your vessel(s) will need to be registered with the Estates Help Desk and the Dept/Divisional Safety Officer.
ii)Your maintenance contractor’s details will need to be registered with the local Estates Contact who will try to co-ordinate the visit of the Inspector with that of the service engineer.
The College currently meets the cost of the Insurance inspection.
Once the Inspector has visited he will issue a certificate. This will be issued as hard and electronic copy to the Estates Helpdesk. The Estates Helpdesk will send hard copy to the local Estates representative and to the Department Safety Officer.
If the Insurance Inspector identifies a safety problem he will inform the user and the local Estates representative, who will be required to isolate and remove from service the piece of equipment pending its repair by the department.See 15.Failing an inspection - actions to be taken
10. Procedures for registration with Estates
You must register existing, newly purchased and second-hand equipment by email to . You will need to provide all the information required on the Estates form. See Appendices Pressure Vessel Registration Form.
In addition, the supplier will provide commissioning and testing data. Pressure vessels may continue to be used in departments for many years, and may even be moved between buildings, campuses etc. It is important that original commissioning and testing data is not lost, so Users should send a copy of the commissioning and testing data to the local estates contact, and give the original to the Department Safety Co-ordinator.
On receipt of the completed form, the Estates Helpdesk will arrange for the Insurance Inspector to visit the Department to make a WSE and inform the local Estates contact, maintenance provider, User, Department Safety Co-ordinator and Divisional Safety Advisor that the Insurance Inspector has been notified. Estates will add the item(s) to the College Register for subsequent annual inspections.
Newly purchased equipment must be registered in the same way, but the insurance inspection will only be necessary 12 months after installation.
If registering newly installed second-hand pressure systems, unless the supplier has provided commissioning and testing data, you will also need to ask the Helpdesk whether or not a WSE needs to be drawn up before first use. Estates will contact the College Insurance Inspector to determine if this is necessary and to arrange a visit.
The maintenance and inspection of fixed installations (those that form part of the building pressure system) is organised by the Local Estates contact on some campuses. It remains the responsibility of the department to check that maintenance and inspection is being done.
If vessels are already registered, they may have been marked with a unique identifier – such as a consecutive number and a Building/campus code. The unique identifier will identify the equipment regardless of where it is located within the College. The unique identifier will appear on the Inspector’s report, and on the College and Divisional database of pressure vessels. The serial number will act as the unique identifier where this is not in evidence.
11. Entry of non-authorised personnel into laboratories
Insurance Inspectors, service engineers, Estates personnel etc may not enter biological Containment Laboratories, plant rooms or other high-risk workplaces unless permit-to-work or equipment decontamination procedures are followed accordingly (see College Guidance Note).
12. Rented and second-hand vessels
Mobile vessels are often on long-term hire. The owner of any pressure vessel is required to have it maintained and tested (and examined where relevant). This applies to nitrogen pressure vessels owned by nitrogen supply companies such as BOC. BOC are responsible for carrying out the annual maintenance and testing on all of their vessels and would normally fix a label to the equipment showing when this was next due. They usually provide a copy of the test certificate to the hirer (on Hammersmith Campus these are kept by Stores), or a copy may be obtained directly from the BOC. The hirer is responsible for checking that tests have been carried out, and for ensuring that vessels failing the test are removed from service and either repaired or replaced by the supply company.
The purchase of second-hand pressure systems should be avoided to minimise risks. They may be in poor condition and the maintenance history may be unknown. Before use of such equipment it is essential that a full service visit (combined with an Insurance Inspection if over 250 bar litre) is arranged. See 10.Procedures for registration with Estates
13. Laboratory equipment which is integral with the building
Some equipment is linked to a building steam generating plant, for example non-self generating autoclaves. This type of machine will be examined in accordance with a WSE, as it forms part of a larger, unseen steam system. Estates will arrange for the maintenance and testing of plant supplying the service to the autoclave. However departments are responsible for ensuring that maintenance and examinations of any attached autoclaves are carried out (as in 6-10). Other items such as gas generators and some compressed gas supply lines may also be part of building-wide pressure system. The Estates Department currently recharges user departments for the cost of maintaining this type of system. Pressure vessels operating via a standard 13 Amp plug are unlikely to fall into this category. If you are uncertain, contact the Estates Helpdesk for advice.