SECTION 8
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Maintenance instructions
Notes on the Plate Heat exchangers
Zilmet UK Plate Heat Exchanger Maintenance Recommendations (as per Zilmet Documentation)
Please, note that only qualified and licensed personnel may perform service and maintenance.
Should the pressure loss through the heat exchanger increase and/or to reach the design temperature be not possible, replace the heat exchanger or clean up
the heat exchange plates. To perform service and control, make sure that the system is off, cooled down and not pressurized, all the electric parts are not
energised and the heat exchanger is completely empty.
In some applications encrustations and/or deposits are likely to build up on the heat exchange plates (e.g. applications with hard water at high operating
temperature). In order to reduce the quantity of encrustations and deposits in the heat exchanger, use oxalic acid solution (HOOCCOOH · 2H2O) at 20° C as a
cleaning fluid: the concentration of the acid must be 5% and the cleaning with acid solution must last 15 minutes at maximum.
Before cleaning, completely empty the heat exchanger: the compatibility of the cleaning fluid with the residues of the operating fluids must be taken into
account in relation with the emanation of toxic or dangerous substances. After the cleaning with acid solution, use sodium bicarbonate (NaHCO3) solution at
20°C to neutralize the acid solution: the concentration of the basic solution must be 2%. The flow rate of both the acid solution and the basic solution through
the heat exchanger must be at least 1.5 times greater than the operating flow rate: the flow rate direction both for the acid solution and the basic solution
must be opposite to the operating flow rate direction. Finally wash the heat exchanger with clean soft water to completely remove every residue of acid and
basic solution.
Any residue of the acid or basic solution in the heat exchanger may cause serious damages to things/properties and persons: after the cleaning, completely
remove every residue of acid and basic solution from the heat exchange plates. In cleaning the heat exchanger as above described, all the technical and
organizing means must be adopted according to the laws and local regulations referring to the occupational health and safety; use the individual protection
devices prescribed in the safety data sheet of each chemical products. All the technical and organizing means must be adopted to treat the waste water
according to environmental laws and local regulations.
Should the fouling factor of the operating fluids be high, completely empty the heat exchanger in case of extended time of not use.
Zilmet S.p.A. shall not be responsible for any damage to things and to properties and/or injuries to persons due
to not observing all the above instructions and, particularly, to improper calculation and choice, installation and
maintenance of this heat exchanger and/or of the connected system.
Plate Heat Exchangers are designed for easy access and simple removal for servicing.
Four Fixing bolts and seals, all available as spares if required. Service engineers are advised to keep a stock of
these spares in case during works one or more gets lost or damaged.
09/17 E & OE
Summary of Contents for Hiper Xi45 INDIRECT HIU 45DHW/10HTG
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