4
Checks on load hook
(see Fig. 4 and Table 1)
Opening dimension C on the hooks is important. A hook with too
large a maximum dimension has been exposed to overloading
or overheating. It therefore does not have the necessary load
capacity. The hooks may also have been exposed to long-term
wear (dimension K).
Hooks must be discarded and replaced if:
•
The maximum C value is exceeded (according to Table 1)
•
The minimum K value falls short (according to Table 1)
•
The hook shows signs of cracking
•
The hook is deformed or otherwise damaged
Defective hooks must be replaced before using the chain block
again.
Table 1
Load
hook
WLL (t)
0,25
0,5
1
2
3
5
10
20
Model
KTHA250
KTHA500
KTHA1000 KTHA2000
KTHA3000 KTHA5000
KTHA10000 KTHA20000
Dimension C nominal mm
24
25,5
30
38,5
41,5
47
55
84
Dimension C max mm
26,4
28,0
33
42,3
45,5
51,7
60,5
92,4
Dimension K nominal mm
15
19
25
33,5
39
44,5
62
93
Dimension K min mm
13,5
17,1
22,5
30,2
35,1
40,0
55,8
83,7
Checks on load chain
(see Fig. 5 and Table 2)
Inspect the load chain over its whole length to detect any deformed or otherwise damaged links. Make a check measurement of suspect links.
Measure the worn areas Also, every 300 mm (normally), make check measurements of the internal length of 5 links (pitch dimension 5xP – ac-
cording to Table 2).
Fig 5 Checking load chain dimensions
Table 2
Load chain
Max. load (t)
0,25
0,5
1
2
3
5-20
Model
KTHA250
KTHA500
KTHA1000
KTHA2000
KTHA3000
KTHA5000-20000
Link diameter nominal mm
4,0
5,0
6,3
8,0
7,1
9,0
Link diameter min. mm
3,6
4,5
5,7
7,2
6,4
8,1
Pitch dimension (5xP) nominal mm
60,0
75,0
95,0
120,0
105,0
135,0
Pitch dimension (5xP) max. mm
61,8
77,2
98,0
123,5
108,1
139,0
The load chain must be discarded and replaced if:
•
cracks are detected on any link
•
any link is deformed or otherwise damaged
•
The minimum value of any link’s diameter falls short
•
the maximum value of the pitch dimension is exceeded at any point
•
the chain is damaged by overheating or has been affected by weld splatter
Load chains must
not
be repaired – they must be replaced by new chain. If it is desired to lengthen the chain, it must be replaced by a new and
longer chain.
Replacement of the chain shall be performed professionally by an authorized repairer and the chain must meet the requirements stated in the
standard EN 818-7.
Fig. 3 The chain must not be twisted Fig. 4 Load hook
C
