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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4.3.2 CLOSED COUPLING
Closed coupling mounting does not take into account the use of a male shaft, therefore the hollow
shaft of the pump is linked directly to the motor male shaft. In this case, it is necessary to use
motors (or motoreducer in the case) capable of standing axial stresses coming from counter-
pressure reactions during pumping.
Note: It is possible, for a special series of feedbox pumps, to link the propeller shaft directly to an
angular worm screw gearmotor, without any support.
4.4 CONNECTING ROD JOINTS
Depending on the type of pump, the connecting rod can use different types of joints (see par. 9.3):
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Type SN1: Pin joint with elastomeric sleeve for smaller pumps.
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Type SN2: Universal joints with elastomeric sleeve and changeable bushing.
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Type SN3: Homokinetic joint with elastomeric sleeve.
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Type SN4: Pin joint with dual elastomeric sleeve and changeable bushing.
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Type SN5: Universal joint with elastomeric sleeve and changeable bushing for high power.
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Type SN6: Universal joint with elastomeric sleeve and changeable bushing.
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Type SN7: Open Pin joint for use with foods without sleeve.
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Type SN8: Pin joint with short bell and flat sleeve.
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Type SN9: Pin joint with short bell for high power.
4.5 SEALING SYSTEMS
The liquid sealing systems may change according to the type of fluid and to the technologic
conditions of pumping. The following types are available (see par. 9.4 and Service manual):
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Type TEN 01: Packing seal.
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Type TEN 02: Fluxed packing seal.
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Type TEN 03: Oil seal.
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Type TEN 04: Single mechanical seal.
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Type TEN 05: Double fluxed mechanical seal.
Note: Mechanical seals can be fluxed, or employ quench techniques.
On request, it is possible to manufacture mechanical seals complying with API 610 standards.
4.6 ACCESSORIES
All pumps may be equipped with accessories to improve their performance.
4.6.1 DRY-RUN PROTECTION
The protection against dry run prevents stator damage whenever the liquid is missing. A thermal
sensor is fitted to the stator, and linked to the electric board. If there is no fluid in the stator, the
stator rubber overheats and the increase in temperature activates the electric circuit, which stops the
motor. This device may be installed subsequently.
