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Metal bellows mechanical seals
- Description
-
Mechanical seals with metal bellows are used if it is necessary to avoid using any elastomer components in the seals, for example, if they are used in the chemical processing industry. The main reason for rejecting elastomers, apart from their chemical disparity, also lies with the small temperature range for elastomer component application. More specifically, when either the maximum or the minimum temperature limit is exceeded, elsatomers will lose their function.
The production of metal bellows is based on connecting a big number of profiled lamels. The number of lamels is determined by the strength which the seal must achieve. The connection is welded.
Mechanical seals with metal bellows are suitable for use in operating conditions which are characterized by high temperature and high pressure. Besides, this type of seal can be used for sealing crystallizable liquids and liquids containing other solid substances, as the bellows are capable of self-purification based on the centrifugal force principle.
Analog:
Burgmann MF95N, John Crane 515 / 5515
Mechanical seals with metal bellows are recommended for sealing:
- highly contaminated liquids, including hydrochloric and acetic acids at elevated temperatures;
- oils and lubricants;
- water and juice;
- in the chemical and oil industries;
- in the organic chemical industry.
Materials for sealing faces:
carbographite
chromium steel
nickel chrome steel
increased rigidity nickel chrome steel
tungsten carbide
silicon carbide
ceramics (AI2O3)
Operating limits:
p = 15 bars
t = -40 ... 220В°C
v = 25 m/s
d1
d3
D6
D7
l1k
l3 l8 20
34
29
35
37.5
30.5 15 22
36
31
37
37.5
30.5 15 24
39
33
39
40
33 15 25
39
34
40
40
33 15 28
42
37
43
42.5
35.5 15 30
44
39
45
42.5
35.5 15 32
46
42
48
42.5
35.5 15 33
47
42
48
42.5
35.5 15 35
49
44
50
42.5
35.5 15 38
54
49
56
45
37 16 40
56
51
58
45
37 16 43
59
54
61
45
37 16 45
61
56
63
45
37 16 48
64
59
66
45
37 16 50
66
62
70
47.5
38 17 53
69
65
73
47.5
38 17 55
71
67
75
47.5
38 17 58
78
70
78
52.5
42 18 60
80
72
80
52.5
42 18 63
83
75
83
52.5
42 18 65
85
77
85
52.5
42 18 68
87
81
90
52.5
41.5 18.5 70
90
83
92
60
48.5 19 75
99
88
97
60
48.5 19 80
104
95
105
60
48.5 19 85
109
100
110
60
48.5 19 90
114
105
115
65
52 20.5 95
119
110
120
65
52 20.5 100
124
115
125
65
52 20.5 + customized seals as per your drawings and specifications
- Name
- NMM-2 Metal bellows mechanical seal
- Description
-
Mechanical seals with metal bellows are used if it is necessary to avoid using any elastomer components in the seals, for example, if they are used in the chemical processing industry. The main reason for rejecting elastomers, apart from their chemical disparity, also lies with the small temperature range for elastomer component application. More specifically, when either the maximum or the minimum temperature limit is exceeded, elsatomers will lose their function.
The production of metal bellows is based on connecting a big number of profiled lamels. The number of lamels is determined by the strength which the seal must achieve. The connection is welded.
Mechanical seals with metal bellows are suitable for use in operating conditions which are characterized by high temperature and high pressure. Besides, this type of seal can be used for sealing crystallizable liquids and liquids containing other solid substances, as the bellows are capable of self-purification based on the centrifugal force principle.
Analog:
AESSEAL BSAI / BSAIG, Burgmann MFL85N / MFLWT80, John Crane 670 / 680, Chesterton 886
Mechanical seals with metal bellows are recommended for sealing:
- highly contaminated liquids, including hydrochloric and acetic acids at elevated temperatures;
- oils and lubricants;
- water and juice;
- in the chemical and oil industries;
- in the organic chemical industry.
Materials for sealing faces:
carbographite
chromium steel
nickel chrome steel
increased rigidity nickel chrome steel
tungsten carbide
silicon carbide
ceramics (AI2O3)
Operating limits:
p = 15 bars
t = -40 ... 220В°C
v = 25 m/s
d1
d3
D4min
l3
I1k
20
34
36
25.5
37.5
22
36
38
25.5
37.5
24
38
40
28
40
25
39
41
28
40
28
42
44
30.5
42.5
30
44
46
30.5
42.5
32
46
48
30.5
42.5
33
47
49
30.5
42.5
35
49
51
30.5
42.5
38
52.5
56
32
45
40
54.5
58
32
45
43
58
62
32
45
45
60
64
32
45
48
63
67
32
45
50
66
70
34
47.5
53
69
73
34
47.5
55
71
75
34
47.5
58
74
78
39
52.5
60
76.5
80
39
52.5
63
79.5
84
39
52.5
65
81.5
85
39
52.5
68
85
89
39
52.5
70
88
92
45.5
60
75
93.5
98
45.5
60
80
98.5
103
45
60
85
105
110
45
60
90
110
115
50
65
95
115
120
50
65
100
120
125
50
65
+ customized seals as per your drawings and specifications
- Name
- NMM-1 Metal bellows mechanical seal
- Description
-
Analog:
John Crane 605, Burgmann MFLWT80 / MFLCT80, AES BSAIG
The solution for extreme temperatures and highly viscous media.
Design with welded metal bellows.
Secondary seals made of thermally expanded graphite.
Hydraulically unloaded.
It does not depend on the direction of rotation of the shaft.
Materials of friction pair:
- carbon graphite (A, B)
- tungsten carbide (U3)
- silicon carbide (Q1, Q2)
Secondary seals:
- thermally expanded graphite (G)
Parameters:
- p = 25 bars
- t = -100 ... 400В°C
- v = 20 m/s
Do not require any adaptation of the pump.
To order seals, it is sufficient to know the pump grade or the manufacturer's seal number.
- Name
- NMM-G Metal bellows mechanical seal
