Vibration Severity Range Limits (Velocity)

From ISO 2372

Vibration Severity Ranges for Machines Belonging to:

In/Sec (PK)

MM/Sec (RMS)

Class I

< 20 HP

Class II

20-100 HP

Class III

>100 HP

Class IV

>100 HP

0.015

0.28

A

A

A

A

(Good)

0.025

0.45

0.039

0.71

B

0.062

1.12

B

0.099

1.80

C

B

0.154

2.80

C

B

(Allowable)

0.248

4.50

D

C

0.392

7.10

D

C

(Tolerable)

0.617

11.2

D

0.993

18.0

D

(Not Permissable)

1.540

28.0

2.480

45.0

3.940

71.0

A: Good

B: Allowable

C: Tolerable

D: Not Permissible

Suggested Classifications:

Class I: Small (up to 15kW) machines and subassemblies of larger machines.

Class II: Medium size (15kW to 75kW) machines without special foundations, or machines up to 300kW rigidly mounted on special foundations.

Class III: Large rotating machines rigidly mounted on foundations which are stiff in the direction of vibration measurement.

Class IV: Large rotating machines mounted on foundations which are flexible in the direction of vibration measurement.