BS EN 13951: 2003
BS EN 13951 Liquid pumps. Safety requirements. Agrifoodstuffs equipment. Design rules to ensure
hygiene in use.
This standard applies to liquid pumps and pump units operating with agrifoodstuffs. It is NOT
intended to be used for pumps handling pharmaceutical products. The
standard aims to ensure that the pump if used in accordance with the
instruction handbook, will remain safe and, provided it is adequately
cleaned, will not cause contamination of the product. Note: due to the
influence of the product, the process and the cleaning regime adopted, the
hygiene of the pump should ultimately be the responsibility of the
end-user.
The standard makes reference to BS EN 1672-2:1997 Food
processing machinery - Basic concepts, Part 2 Hygiene requirements.
BS
EN 13951 is one means of complying with the specific essential
requirements of the Machinery Directive 98/37/EC (amended by 98/79/EC).
We need to request specific information at the time of
quotation:
- Cleanability level required - levels 1, 2, 3 or 4
(see table below) - the level
selected should take into account the risks arising from the pumped
product, the placement of the pump in the process and the cleaning regime
anticipated.
- If abrasive fluids are pumped (eg crystalline or fibrous
foodstuffs), then the possibility of abrasive wear needs to be discussed
and the choice of materials agreed.
- Surface finishes - the cleanability depends of the topography of
the surface (profile, roughness), local fluid velocities, pump type,
application and cleaning process. What is required depends on the pump
application, eg the product itself (viscosity / effective viscosity and
tenacity of residues) and where the pump is in the process (ie handling of
raw, semi-processed or final product). We recommend 0.8µmRa
for our pure finish.
- Connections - the customer will select the most appropriate
connection having considered the hazards which may arise from their
selection, installation and operation. Retention of product may be due to
misalignment, physical change from thermal or chemical effects, incorrect
installation (over or under tightening, omission of parts), or gaps and
cavities inherent in the design. Hazards can arise from forces and moments
from the pipework, unscrewing or mechanical shocks.
- Seal types. The hygienic risk level depends on the pumped product
and the seal type. Note that mostly the liquids will be 'Low viscous', and
therefore the risk with a single mechanical seal will be low or medium.