22
Planned Maintenance Programmes
(Preventative/Precautionary Maintenance)
MAINTENANCE
General
Mira products are precision-engineered and should give continued superior and safe
performance, provided:
1.
They are installed, commissioned, operated and maintained in accordance with
the recommendations stated in this Product Manual.
2.
Periodic attention is given as necessary to maintain the product and its
associated installation components in good functional order. Guidelines for
frequency are given below.
The principle functional parts affecting the abilityof the valve to supply safe mixed water
temperatures are contained in a cartridge. The designed minimum service life of this
cartridge is five years under normal operating conditions. However, when supply
conditionsand/or usage patterns do not conform to ‘normal operating conditions’ the
cartridge should be replaced more frequently (
refer to normal operating conditions
).
In all cases where users are deemed at risk, irrespective of supply or usage conditions
or the evidence of any performance checks, the cartridge should be replaced at
intervals of no more than three years.
It is recommended that the user maintains a log of all periodic performance checks,
which, for Type 3 valves in healthcare installations, should consist of the in-service
tests shown in
Figure 6
(page 31), together with a record of any service work
carried out and cartridge exchange details.
The use of main supply-line or zone strainers (recommended maximum mesh aperture
dimension is 0.5 mm) will reduce the need to remove debris at each mixing valve point.
The frequency and extent of attention required will vary according to prevailing site
and operational conditions. In applications (such as non-healthcare) where the risks
to the user are too slight to justify the full in-service test procedure and maintenance
logging process, the procedure under Performance check is suggested to cover
average duty and site conditions.
- In-service tests
- Regular temperature checking in between In-service tests
- Maintenance of a log of In-service tests and temperature checks together
with details of critical parts replacements and any other service work.
1.
In all other cases it is recommended that a routine of preventative maintenance
be employed which is based upon assessment of the risks to the user. The
following practices are intended to support such a routine: