Sermatech Ethylene
Flexijoint   Pressure Ratings For Flexijoint® Bellows
 

The pressure rating of a Flexijoint Bellow is primarily effected by four(4) factors; size, style, number of convolutions and temperature. These factors must be considered when calculating the pressure rating of a bellows.
To determine the maximum, non-shock, operating pressure(P) for a specific bellows:

    P = Pressure Factor(Fp) X Style Factor(Fs)

Example 1:
The maximum operating pressure for a 4" x 4 conv. bellows at 250°F.
           P = 42 x 1.58 = 66.4 psi

Example 2:
A 6" x 5 convolution bellows operating at 50psi. The maximum safe operating temperature would be found by dividing the pressure by the factor(Fs) for that bellows to determine the temperature factor(Fp), then finding the temperature by using the Pressure Factor(Fp) curve above.
                       (Fp) = 50 / 1.30 = 38.5    or   approximately 275°F

 

Size / Style Factor (Fs)

Number of Convolutions
Size Type 2 3 4 5 6 7 8 9 10
1/2

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.60		 1.82
1.25		 1.80
1.07		 1.69
0.89		 1.59
0.68		 1.50
0.61		 1.41
0.51
3/4

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.62		 1.82
1.27		 1.80
1.10		 1.70
0.91		 1.61
0.70		 1.52
0.64		 1.44
0.54
1

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.63		 1.82
1.29		 1.80
1.13		 1.71
0.97		 1.62
0.73		 1.54
0.67		 1.47
0.57
1-1/2

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.66		 1.82
1.38		 1.80
1.19		 1.71
1.02		 1.62
0.87		 1.54
0.75		 1.47
0.64
2

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.67		 1.82
1.39		 1.80
1.20		 1.74
1.03		 1.70
0.88		 1.73
0.76		 1.77
0.65
3

Antisquirm
Flexijoint

 2.25
2.25		 1.93
1.93		 1.87
1.67		 1.82
1.42		 1.81
1.18		 1.77
1.00		 1.74
0.85		 1.70
0.72		 1.67
0.62
4

Antisquirm
Flexijoint

 2.25
2.25		 1.86
1.86		 1.82
1.58		 1.78
1.34		 1.75
1.14		 1.74
0.97		 1.70
0.83		 1.67
0.70		 1.63
0.60
6

Antisquirm
Flexijoint

 2.10
2.10		 1.80
1.80		 1.77
1.53		 1.74
1.30		 1.71
1.11		 1.67
0.94		 1.64
0.78		 1.61
0.68		 1.58
0.58
8

Antisquirm
Flexijoint

 2.04
2.04		 1.75
1.75		 1.72
1.50		 1.69
1.28		 1.66
1.10		 1.63
0.94		 1.60
0.80		 1.58
0.69		 1.55
0.59
10

Antisquirm
Flexijoint

 1.95
1.95		 1.72
1.72		 1.69
1.45		 1.64
1.22		 1.64
1.07		 1.61
0.91		 1.58
0.78		 1.56
0.67		 1.53
0.58
12

Antisquirm
Flexijoint

 1.85
1.85		 1.65
1.65		 1.61
1.37		 1.60
1.19		 1.57
1.04		 1.54
0.89		 1.52
0.77		 1.50
0.66		 1.48
0.56
14

Antisquirm
Flexijoint

 1.78
1.78		 1.58
1.58		 1.55
1.31		 1.53
1.10		 1.51
0.94		 1.49
0.80		 1.47
0.69		 1.45
0.59		 1.43
0.50
16

Antisquirm
Flexijoint

 1.70
1.70		 1.53
1.53		 1.52
1.20		 1.50
0.98		 1.48
0.84		 1.45
0.72		 1.43
0.61		 1.42
0.53		 1.40
0.45
18

Antisquirm
Flexijoint

 1.62
1.62		 1.51
1.51		 1.49
1.18		 1.47
0.96		 1.45
0.83		 1.44
0.71		 1.43
0.61		 1.42
0.52		 1.40
0.45
20

Antisquirm
Flexijoint

 1.54
1.54		 1.41
1.41		 1.39
1.16		 1.38
0.93		 1.36
0.80		 1.35
0.69		 1.34
0.59		 1.32
0.51		 1.31
0.43
24

Antisquirm
Flexijoint

 1.47
1.47		 1.34
1.34		 1.33
1.15		 1.31
0.92		 1.30
0.79		 1.29
0.68		 1.28
0.58		 1.26
0.50		 1.25
0.43
30

Antisquirm
Flexijoint

 1.38
1.38		 1.28
1.28		 1.27
1.11		 1.26
0.87		 1.24
0.75		 1.23
0.63		 1.22
0.54		 1.21
0.46		 1.20
0.39
36

Antisquirm
Flexijoint

 1.25
1.25		 1.20
1.15		 1.13
1.08		 1.07
0.84		 1.05
0.72		 1.01
0.66		 0.98
0.52		 0.96
0.44		 0.93
0.38