INSTRUCTIONS WS11Q004
Wärtsilä 4-stroke Technical Services
Issue 3, 30 September 2014
Inspection of CENTA CENTAXSEC couplings Information to Operators and Owners of concerned installations
For your information Concerned engines / components CENTA CENTAX type coupling on: WÄRTSILÄ® 20, 32, 32DF, 32GD, 34DF, 46, 46F, 50DF, 50SG WÄRTSILÄ® Vasa 22, 22/26, 32, 32LN, 32LNGD Reference 11 Coupling Validity / Issue Until further notice, replacing issue 02 dated 09 November 2007.
Wärtsilä Finland Oy Services P.O. Box 252 (Tarhaajantie 2) FIN-65101 Vaasa, Finland
24 hrs Tel: +358 10 709 080 Switchboard Tel: +358 10 709 0000 Fax: +358 6 356 7374
INSTRUCTIONS WS11Q004, Issue 3, Page 2 / 2 + 23
Introduction Centa Antriebe Kirschey GmbH has published evaluation criteria for their CENTAXSEC type couplings. These evaluation criterias are enclosed in this document. Instructions
Instructions The life time of a rubber coupling is influenced by many factors, such as age hardening, torque (over)loading, thermal (over)loading and environmental factors. In order to prevent coupling failure regular inspections must be carried out. The evaluation criteria shall be used when inspecting the coupling
Recommendation Wärtsilä recommends the following inspections. Visual inspection of the rubber elements: o
After 1 000 operating hours
o
After 4 000 operating hours
o
All further 6 000 operating hours, respectively 1x annually.
NOTE: Shorten the inspection intervals accordingly if the permanent set is close to maximum, cracks or detachments has occurred or rate of change of these is increasing.
Enclosures “Element evaluation, CENTAX-SEC couplings, W000-00002-EN, rev. 3”, 23 pages.
Contacts For questions about the content of this Instructions bulletin, or if you need Wärtsilä assistance, services, spare parts and/or tools, please contact your nearest Wärtsilä representative. If you don’t have the contact details at hand, please follow the link “Contact us” – “24h Services” on the Wärtsilä webpage: www.wartsila.com
© 2014 Wärtsilä Finland Oy – All rights reserved No part of this publication may be reproduced or copied in any form or by any means (electronic, mechanical, graphic, photocopying, recording, taping or other information retrieval systems) without the prior written permission of the copyright holder. Wärtsilä Finland Oy makes no representation, warranty (express or implied) in this publication and assumes no responsibility for the correctness, errors or omissions for information contained herein. Information in this publication is subject to change without notice. Unless otherwise expressly set forth, no recommendation contained in this document or any of its appendices is to be construed as provided due to a defect of the product, but merely as an improvement of the product and/or the maintenance procedures relating thereto. Any actions by the owner/operator as a result of the recommendations are not covered under any warranty provided by Wärtsilä and such actions will thus be at the owners/operators own cost and expense. NO LIABILITY WHETHER DIRECT, INDIRECT, SPECIAL, INCIDENTAL OR CONSEQUENTIAL, IS ASSUMED WITH RESPECT TO THE INFORMATION CONTAINED HEREIN. THIS PUBLICATION IS CONFIDENTIAL AND INTENDED FOR INFORMATION PURPOSES ONLY.
Element evaluation
CENTA instructions CENTAX-SEC Couplings W000-00002-EN Rev. 3
CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Contents 1
General notes ......................................................................................... 4
2
Safety ..................................................................................................... 5 2.1
2.2 3
2.1.1
Signal words ......................................................................... 5
2.1.2
Pictograms ............................................................................ 6
Qualification of the assigned personnel ................................................. 6
Element evaluation ................................................................................. 7 3.1
3.2
3.3
4
Safety instructions ............................................................................. 5
General information ........................................................................... 7 3.1.1
Permanent set ....................................................................... 8
3.1.2
Cracking ............................................................................... 9
3.1.3
Surface assessment ..............................................................10
Ring elements ..................................................................................11 3.2.1
Permanent set of ring elements ..............................................11
3.2.2
Cracking on ring elements ......................................................12
Segmented elements .........................................................................18 3.3.1
Permanent set of segmented elements CX-276 to CX-294, CX-496 and CX-498 ..............................................................18
3.3.2
Permanent set of segmented elements CX-391 to CX-394 ..........19
3.3.3
Cracking of segmented elements ............................................20
Treating cracks preventively ................................................................. 23
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Index of illustrations Fig. 3-1 Fine diamond shaped cracks on the rubber surface ........................... 10 Fig. 3-2 Permanent set of ring elements ...................................................... 11 Fig. 3-3 Circumferential cracks on ring elements........................................... 12 Fig. 3-4 Occasional cracks on ring elements ................................................. 12 Fig. 3-5 Permanent set: Example segmented element CX-276 ........................ 18 Fig. 3-6 Permanent set: Example segmented element CX-391 ........................ 19 Fig. 3-7 Circumferential cracks on segmented elements................................. 20 Fig. 3-8 Occasional cracks on segmented elements ....................................... 20
Index of tables Table 3-1 Permanent set and crack depths (size 50…69) ............................... 13 Table 3-2 Permanent set and crack depths (size 70…78) ............................... 14 Table 3-3 Permanent set and crack depths (size 80…90) ............................... 15 Table 3-4 Permanent set and crack depths (size 176…188) ............................ 16 Table 3-5 Permanent set and crack depths (size 190…194) ............................ 17 Table 3-6 Permanent set and crack depths (size 276…288) ............................ 21 Table 3-7 Permanent set and crack depths (size 290…498) ............................ 22
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 1
General notes
IMPORTANT CENTA does not assume any responsibility for damages and disruption of operations resulting from non-observance of these CENTA instructions.
The CENTA Antriebe Kirschey GmbH remains owner of the copyright to these CENTA instructions. Please contact our head office, if you have any technical enquiries: CENTA Antriebe Kirschey GmbH Bergische Strasse 7 42781 Haan GERMANY Phone +49-2129-912-0 Fax +49-2129-2790
[email protected] www.centa.info
CENTA Antriebe Kirschey GmbH
4 / 23
CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 2
Safety These CENTA instructions should enable the user to:
assess the coupling independently and with simple means
to care for the coupling properly
to preventively treat smaller cracks
These CENTA instructions must therefore be read carefully and understood by the persons responsible before commencing work on and with the coupling.
WARNING Injuries and material damages can occur by:
non-compliance with the respective safety and accident prevention regulations valid at the place of use
The respective safety and accident prevention regulations valid at the place of use must be observed for the tasks described in these CENTA instructions.
2.1
Safety instructions The safety instructions are characterised by a pictogram in the chapters of these CENTA-instructions.
2.1.1
Signal words The following signal words are used in the safety instructions:
DANGER
Denotes the immediate threat of danger. If not prevented, fatal or extremely serious injuries can result.
WARNING
Denotes a potentially dangerous situation. If not prevented, fatal or extremely serious injuries can result.
CAUTION
Denotes a potentially dangerous situation. If not prevented, minor injuries and/damage to property may result.
IMPORTANT
Denotes application tips and particularly useful information. This is not a signal word denoting a dangerous or damaging situation.
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 2.1.2
Pictograms Possible pictograms in the safety precautions:
Warning of a hazardous area
Do not switch
Use protective gloves
Use protective goggles
2.2
Qualification of the assigned personnel All tasks described in these CENTA instructions may only be carried out by trained, instructed and authorised persons.
WARNING Injuries and material damages can occur by:
Work on the coupling, which is not described in these CENTA instructions.
Only carry out tasks, which are described in these CENTA instructions.
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3
Element evaluation
3.1
General information
WARNING Injuries can occur as a result of:
Contact with rotating parts
Before starting work at the coupling, switch off the plant and secure against unintentional start-up.
Visual inspection of the rubber elements/rubber segments:
After 1000 operating hours
After 4000 operating hours
All further 6000 operating hours, respectively 1x annually
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.1.1
Permanent set CENTAX-SEC rubber elements/rubber segments transfer the torque by thrust. Different operating conditions and thereby resulting stresses lead to different permanent sets of the rubber elements/rubber segments. The permanent set of each individual rubber element must be assessed for several rubber elements/rubber segments lined up in succession.
IMPORTANT Replace the rubber elements/rubber segments in the following cases:
The permanent set S (see Table 3-1 … 3-7) is exceeded.
IMPORTANT Couplings with several rubber elements / rubber segments in series require another intensive inspection of the rubber elements / rubber segments if:
the difference SD between the largest determined permanent deformation Smax and the smallest determined permanent deformation Smin is greater than 50% Smax (see examples below). Example 1: Smax = 40mm; Smin = 30mm; SD = 10 mm = 25% Smax Rubber elements can further be used. Example 2: Smax = 40mm; Smin = 16mm; SD = 24 mm = 60% Smax The result of the further intensive inspection decides whether or not the rubber elements / rubber segments can further be used. Contact CENTA-Service in the CENTA headquarters for details (address see Chapter 1).
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.1.2
Cracking Pronounced signs of wear, such as deep cracks, impair torque transmission by reduction of the cross section. Such cracks at the locations illustrated in the following figures may only occur up to the specified depths. We recommend preventively rounding off cracks, in order to limit the damage process under normal operating conditions. Determining and eliminating the reason of cracking. Inform CENTA immediately together with photos of the documented cracks and damages, if the maintenance personnel cannot determine the reason for cracking (Address see Chapter 1). Inform CENTA immediately together with photos of the documented debonding and damages, if the rare case occurs, that the rubber/metal connection debonds (Address see Chapter 1). An immediate replacement of the elements could be necessary.
IMPORTANT Replace the rubber elements/rubber segments in the following cases:
Cracks running over the entire element width and which have achieved the values indicated in the tables 3-1 … 3-7.
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.1.3
Surface assessment
Fig. 3-1 Fine diamond shaped cracks on the rubber surface The rubber surfaces harden and become porous due to the influence of e.g. heat and ozone. This results in fine diamond shaped cracks.
IMPORTANT These signs of wear do not represent any impairment of the transmission capacity.
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.2
Ring elements
3.2.1
Permanent set of ring elements
Fig. 3-2 Permanent set of ring elements Item
Info
Designation
a
Twist angle marking in as-delivered state
b
Twist angle marking with permanent set
Remark
Determine and document the permanent set S by means of the twist angle marking.
The permissible permanent set S for ring elements can be inferred from Table 3-1 … 3-5 .
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.2.2
Cracking on ring elements
Fig. 3-3 Circumferential cracks on ring elements
Fig. 3-4 Occasional cracks on ring elements
Examine rubber elements for cracks. Mark and photograph cracks. Determine and document crack depths A and B and examine again latest after three months.
The permissible crack depths A and B for ring elements can be inferred from Table 3-1 … 3-5 .
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
50/52
51
55/56
64
65
67
66/68
69
Shore hardness (Shore A)
Permanent set S [mm]
45
40
50
43
60
37
70
22
45/50
42
60
40
70
23
45/50
42
60
39
70
23
50
51
60
45
70
23
50
47
60
43
70
24
50
49
60
43
70
23
50
38
60
34
70
20
50
41
60
36
70
21
Allowable crack depth A [mm]
B [mm]
2
3.5
3
5
2
3.5
3
5
2.5
4
3.5
6
3
5
3
5
Table 3-1 Permanent set and crack depths (size 50…69)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
70/71
72
75
78
Shore hardness (Shore A)
Permanent set S [mm]
50
46
60
40
70
23
50
47
60
42
70
25
50
48
60
43
70
27
50
61
60
54
70
34
Allowable crack depth A [mm]
B [mm]
3.5
6
4
7
5
8.5
5.5
9.5
Table 3-2 Permanent set and crack depths (size 70…78)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
80
81
82
84
85
88
90
Shore hardness (Shore A)
Permanent set S [mm]
50
61
60
54
70
34
50
64
60
56
70
35
50
72
60
64
70
42
50
76
60
69
70
43
50
82
60
73
70
47
50
85
60
74
70
46
50
91
60
81
70
49
Allowable crack depth A [mm]
B [mm]
6
10
8.5
14.5
6.5
11
7.5
13
8.5
14.5
8
13.5
9.5
16
Table 3-3 Permanent set and crack depths (size 80…90)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
176
177
179
181
183
184
185
186
187
188
Shore hardness (Shore A)
Permanent set S [mm]
50/60
48
70
29
50/60
52
70
32
50/60
58
70
34
50/60
63
70
39
50/60
65
70
40
50/60
72
70
43
50/60
71
70
47
50/60
87
70
55
50/60
92
70
55
50
101
60
95
70
58
Allowable crack depth A [mm]
B [mm]
7
11.5
7.5
13
8
14
8.5
15
9.5
16
10
17
11
18
12
20
15
24
16
27
Table 3-4 Permanent set and crack depths (size 176…188)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
190
192
193
194
Shore hardness (Shore A)
Permanent set S [mm]
50
104
60
99
70
63
50/60
98
70
62
50
104
60
98
70
62
50
108
60
105
70
65
Allowable crack depth A [mm]
B [mm]
17
29
18
31
20
34
20
34
Table 3-5 Permanent set and crack depths (size 190…194)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.3
Segmented elements
3.3.1
Permanent set of segmented elements CX-276 to CX-294, CX-496 and CX-498
Fig. 3-5 Permanent set: Example segmented element CX-276
Determine and document permanent set S by means of the plates.
The permissible permanent set S for segmented elements size CX-276 to CX-294, CX-496 and CX-498 can be inferred from Table 3-6 … 3-7 .
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.3.2
Permanent set of segmented elements CX-391 to CX-394
Fig. 3-6 Permanent set: Example segmented element CX-391
Determine and document permanent set S by means of the plates.
The permissible permanent set S for segmented elements size CX-391 to CX-394 can be inferred from Table 3-6 … 3-7 .
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 3.3.3
Cracking of segmented elements
Fig. 3-7 Circumferential cracks on segmented elements
Fig. 3-8 Occasional cracks on segmented elements
Examine rubber segment for cracks. Mark and photograph cracks. Determine and document crack depths A, B and C and examine again latest after three months.
The permissible crack depths A, B and C for segmented elements can be inferred from Table 3-6 … 3-7 .
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
276
277
279
281
283
284
285
286
287
288
Shore hardness (Shore A)
Permanent set S [mm]
50/60
42
70
28
50/60
46
70
28
50/60
48
70
31
50/60
56
70
35
50/60
58
70
37
50/60
63
70
38
50/60
71
60
48
50/60
77
70
48
50/60
86
70
52
50
98
60
94
70
58
Allowable crack depth A [mm]
B [mm]
C [mm]
7
11.5
27
7.5
13
30
8
14
33
8.5
15
34
9.5
16
38
10
17
40
11
18
43
12
20
46
15
24
57
16
27
63
Table 3-6 Permanent set and crack depths (size 276…288)
CENTA Antriebe Kirschey GmbH
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CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings Size
290
292
293
294
391/392
393/394
496
498
Shore hardness (Shore A)
Permanent set S [mm]
50
115
60
112
70
71
50
109
60
106
70
68
50
111
60
105
70
67
50
119
60
115
70
73
50
184
60
162
70
104
50
216
60
184
65
154
70
118
50
104
60
99
70
62
50
106
60
101
70
62
Allowable crack depth A [mm]
B [mm]
C [mm]
17
29
68
18
31
73
20
34
78
20
34
79
18
30
72
20
34
80
21
36
86
23
39
92
Table 3-7 Permanent set and crack depths (size 290…498)
CENTA Antriebe Kirschey GmbH
22 / 23
CENTA instructions
W000-00002-EN
Element evaluation
Rev. 3
CENTAX-SEC Couplings 4
Treating cracks preventively We recommend rounding off cracks preventively. Contact CENTA-Service in the CENTA headquarters for details (address see Chapter 1).
CENTA Antriebe Kirschey GmbH
23 / 23
