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MAN16MG05

instructions

for

use

series

drh

1/2/3/4 -

dst

drt

6.3.3 Check of efficiency of parts and components

•

The metal structures, as well as normal alterations due to environmental factors and wear of mobile parts (hinges),

can be subject, even inadvertently or during handling operations, to bumps, contact or grazing with other
equipment or to anomalous strain which can cause damage to the frames, welding and pivots. Therefore, after
careful cleaning, the structures must periodically undergo scrupulous checks to ensure their suitability and if
necessary, any damage be remedied.

• The brackets, composed of plates and pivot, which form hinged elements, are subject to wear as they are

mobile, swinging elements exposed to sliding friction in the areas of contact. If excessive wear is found,
substitute them during the check.

• All screw bolts, high resistance plugs and pins must be disassembled and carefully checked annually, and so

must the relative seating.

For the individual parts of the DRH electric rope hoists and relative trolleys the following instructions

must be strictly adhered to:

Annual check of the efficiency of structural elements, pivots and hinges

(fig. 132):

Repair or substitute hinged parts where one finds:

• deformation:

lengthening, crushing, staining, bending

• wear:

worn parts, scarcement, incisions, abrasions, corrosion, oxidation, scratching,

peeling point

• breakage:

cracks in the welding, cracking, cuts or incisions, broken parts

• variation of a section

≥

10%, or of the diameter or thickness

≥

5% compared to initial

values.

DONATI TECHNICIAN

DONATI SERVICE

fig. 132

instructions

for

use

series

drh

1/2/3/4 -

dst

drt

MAN16MG05

• Rope check:

• The rope and rope guide undergo wear

• Check the state of the rope to localise any degradation

• Regular lubrication will lengthen its life

•

It is often possible to improve a rope performance by ascertaining what causes deterioration by examining
used ropes.

• During inspections it is worthwhile to carefully examine the parts of the rope which wind around the

pulleys and which are near the fixing points at the ends

• Record in the checks register the date and results of the examination so that in the future, the time when

the rope will have to be replaced can be predicted

• The decision to replace the rope, in accordance with the ISO 4309:2004, must be determined by

the number and position of breaks in the threads which make up the strands, by the level of wear and
corrosion and by other relevant damage or lacerations

• The breaks are often difficult to see as the ends of the broken threads stay in the original position and do

not stick out from the surface of the rope

• In order to find these breaks it is necessary to remove the lubricant which covers the rope, scrape a piece

of soft wood along the length of it and, if possible, bend the rope by hand, in order to force the ends of
the threads to stick up and become visible

• Perform a check “with no load” so that detecting a break is easier

• Check for any deformations of the rope, which may be of helicoidal type; with a reduced diameter

concentrated in short lengths; with local flattening of the rope or angular deformations due to external

causes of high intensity. In the first situation the deformation causes irregular movements of the rope
during dragging, these movements are the main cause of increased wear and breakage of the threads,
the second situation is frequently found at the anchorage points at the ends of the rope.

• During rope inspections check for

(see ISO 4309:2004):

• The number of broken threads

• Any reduction in the diameter of the rope

• Corrosion and wear of the rope

• Deformation of the rope

• Any effects which may have been caused by heat exposure

Quarterly check of efficiency of the lifting rope and of the fixing elements

(anchorage with

wedge) - (fig. 133):

• The rope must be replaced if it shows (see ISO standard 4309:2004):

• a reduction in the diameter

≥

7% due to corrosion and wear

• one or more broken strands
• deformation with: permanents bends, flattening etc.
• the rope core coming out
• one or more strands which are loose or sticking out even when under strain
•

the total number of broken threads, in a length = to 6 diameter,

≥

10% of the number of

threads in the external strand (see “rope formation” - fig. 133)

•

alterations caused by unusual thermal input (recognisable externally by the annealed iron

colour that the rope assumes)

• PFor the characteristics of the rope of the DRH hoists see table

(fig. 133)

• During rope checks, the operator must wear gloves in order to avoid the danger of

pricking or perforation due to contact with broke threads!

• For rope replacement see point 6.6.1