Varisco S.p.A.
Z.I. Nord - Terza Strada, 9 - 35129 PADOVA – ITALY
Tel.+39.049.8294111 Email: [email protected]
Fax+39.049.8076762 Web: www.variscospa.com
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Through the cleaning windows if present on the pump body.
•
Manually, disassembling the pump
•
Automatically (CIP) for pumps with suitable connectors.
8.2 STATORS AND SEALING SYSTEMS
8.2.1 STATORS
Approx. every 900 hours of operation, it is necessary to check the wear, especially for the stator and
the sealing system (packing or mechanical seal).
The frequency of control operations will be determined according to the wear of both of them, not
exceeding anyway 1500 working hours.
8.2.2 SEALS
8.2.2.1 PACKING SEALS
Packing seals limit the leakage of product, but do not prevent it entirely. A small leakage is
necessary to prevent excessive friction and subsequent possible overheating.
At startup, after replacement, tighten the gland bush lightly until it is set and in ideal working
conditions (for 10-15 min.), then tighten it more strongly to obtain the smallest possible leakage.
FUNCTIONING ERRORS AND THEIR CONSEQUENCES
In case the pack were excessively compressed, the following damages may arise:
•
Dry working
•
Burnt pack
•
Scored shaft (with subsequent leakage of fluid).
NOTE: The packing seal is in optimal working condition if constantly damped by the product to be
pumped.
8.2.2.2 SINGLE MECHANICAL SEAL
The type and brand of the mechanical seal used is specified in the order confirmation. In case of
significant leakage, check the surfaces of the seal faces and seat. Replace them if necessary.
8.2.2.3 MECHANICAL SEALS FOR VERTICAL PUMPS
Use particular caution on vertical pumps with motor on top (type SV/VM).
At startup, the mechanical seal has not yet been in contact with the fluid and briefly works dry until
the air in the pump body has been expelled.
At first startup or after a prolonged stop, lubricate the mechanical seal before starting the pump.
Lubricate with water, glycerine or oil, depending on the product to be pumped: check for
compatibility with the elastomers of the mechanical seal.
8.3 CONTROL AND REPLACEMENT OF ARTICULATED JOINTS
The driveline joint is one of the most stressed parts of the pump, therefore needs regular and
adequate controls.
On any kind of joint, it is always necessary, though the pump may work normally, to immediately
replace damaged sleeves, even if the damage is slight.
Sleeves of any kind are to be kept in warm water for some minutes before replacement, in order to
soften them and ease the fitting to both ends of the joint and prevent damage on the elastomer they
are made of.
