1. Written scheme of examination
Requirements for a Written Scheme are:
A written scheme of examination is a document containing information about selected items of plant or equipment which form a pressure system, operate under pressure and contain a "relevant fluid". The term "relevant fluid" is defined in the Regulations and covers compressed or liquefied gas including air above 0.5 bar pressure (approximately 7 psi), pressurised hot water above 110 degrees Celsius and steam at any pressure.
Items of plant forming the pressure system should be included in a written scheme of examination if a failure of the item could unintentionally release pressure from the system, and the resulting release of stored energy could cause injury.
2. Responsibility of users and owners to define scope of scheme
The user of installed systems and the owner of mobile systems are responsible for deciding which pressure system is covered by the Regulations. To arrive at a properly informed decision, users or owners may seek advice from other sources. These could be Insurance Companies, in-house engineering staff, inspection bodies and consultants. However, the legal responsibility for defining the scope of the scheme rests with users or owners. The written scheme should generally cover all items within a self-contained pressurised system, which may give rise to danger. If there is more than one self-contained pressure system, there will be a need for more than one written scheme.
3. Confirmation of scope of scheme
When the scope of the written scheme has been decided, the user or owner of the pressure system should contact a person with sufficient knowledge and experience about the system. This person should be capable of offering informed advice on the subject. Discussions on the scope of the written scheme should be made with them, and if necessary, modify the scope accordingly.
4. Competent person
The users or owners of pressure systems need to select a competent person and in doing so should take reasonable steps to ensure that the competent person selected can actually demonstrate competence, i.e. the necessary wealth of knowledge, experience and independence. In practice the competent person is likely to be a body or company specialising in engineering inspection work or an Insurers engineering surveyor.
5. Review of written scheme
The written scheme of examination must be 'suitable' throughout the lifetime of the plant or equipment and it follows that it should be reviewed, and when necessary, revised. For example, as the age of some plant increases there may be a need to carry out more frequent examinations, or change their content or type. It is the user's responsibility under the Regulations to ensure that the content of the written scheme is reviewed at appropriate intervals by a competent person to determine if it remains suitable, but clearly the competent person should be in a position to give advice on this aspect.
6. Legal responsibility
Users and owners of pressure systems covered by a written scheme of examination have a legal responsibility to ensure that a competent person examines the systems in accordance with the scheme.
The user of an installed system and the owner of a mobile system shall ensure that the system is properly maintained in good repair, so as to prevent danger. The maintenance needs should be determined taking into account the age of the system, the conditions of operation and the environment in which it works.
Consideration should be given to what systems or parts require routine checks and replacement e.g. lubrication fluids and coolants. Some parts of systems should be subject to sample inspection during regular shutdowns when signs of deterioration, leakage, external damage or corrosion are apparent.
Pipework may not be subject to examination under the written scheme, but periodic checks should be carried out at the more vulnerable areas such as expansion loops, bends and low points.
Systems which, have been out of service, will need more detailed checks when being brought back into use.
Protective devices must be checked at appropriate intervals to ensure they remain in efficient working order. Where manufacturers/suppliers instructions are appropriate to the system and are sufficiently comprehensive they should be used to assist maintenance.
8. Keeping of records
The last report relating to the system made by a competent person and also any previous reports must be kept if they contain information that will help in assessing whether the system is safe to operate, or any repairs or modifications to the system can be carried out safely.
Records should also be kept of any modifications or repairs to the pressure systems. Where the user or owner of a pressure system changes, the previous owner or user shall as soon as practicable give to the new user or owner in writing anything (relating to the system or part thereof) kept by him.
Where the Regulations require records to be kept in writing, then they can be kept in a form that is capable of being reproduced as a written copy if required. Generally records can therefore be held on computer providing they are secure from loss or unauthorised interference.