ISO Vibration Standards Reference

Comprehensive guide to ISO vibration standards for industrial equipment

description ISO 10816-7

Pump

Rotodynamic pumps for industrial applications, including measurements on rotating shafts

speed Measurement: Rms Velocity Mm Per Second
category Category I

Power Range: less than 200kW above 1kw

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2.5 - 4.0 Acceptable for unrestricted long-term operation
Zone C
Warning 		4.0 - 6.6 Unsatisfactory for long-term continuous operation
Zone D
Danger 		6.6+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2.5 Boundary between Zone A and Zone B
B/C 4.0 Boundary between Zone B and Zone C
C/D 6.6 Boundary between Zone C and Zone D

info Pumps required to have a high level of reliability, availability or safety reasons

category Category I

Power Range: more than 200kW

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 3.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		3.5 - 5.0 Acceptable for unrestricted long-term operation
Zone C
Warning 		5.0 - 7.6 Unsatisfactory for long-term continuous operation
Zone D
Danger 		7.6+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 3.5 Boundary between Zone A and Zone B
B/C 5.0 Boundary between Zone B and Zone C
C/D 7.6 Boundary between Zone C and Zone D

info Pumps required to have a high level of reliability, availability or safety reasons

category Category II

Power Range: less than 200kW above 1kw

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 3.2 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		3.2 - 5.1 Acceptable for unrestricted long-term operation
Zone C
Warning 		5.1 - 8.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		8.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 3.2 Boundary between Zone A and Zone B
B/C 5.1 Boundary between Zone B and Zone C
C/D 8.5 Boundary between Zone C and Zone D

info Pumps for general or less critical application

category Category II

Power Range: more than 200kW

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 4.2 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		4.2 - 6.1 Acceptable for unrestricted long-term operation
Zone C
Warning 		6.1 - 9.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		9.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 4.2 Boundary between Zone A and Zone B
B/C 6.1 Boundary between Zone B and Zone C
C/D 9.5 Boundary between Zone C and Zone D

info Pumps for general or less critical application

description ISO 20816-2

Steam Turbine and Generators

Land-based gas turbines, steam turbines and generators in excess of 40 MW, with fluid-film bearings and rated speeds of 1500 r/min, 1800 r/min, 3000 r/min and 3600 r/min

view_module Vibration of non-rotating parts
Measurement: Rms Velocity Mm Per Second

Machine: steam turbine and generator

Speed Range: 1500 or 1800 shaft rotational speed

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2.8 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2.8 - 5.3 Acceptable for unrestricted long-term operation
Zone C
Warning 		5.3 - 8.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		8.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2.8 Boundary between Zone A and Zone B
B/C 5.3 Boundary between Zone B and Zone C
C/D 8.5 Boundary between Zone C and Zone D

Machine: steam turbine and generator

Speed Range: 3000 or 3600 shaft rotational speed

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 3.8 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		3.8 - 7.5 Acceptable for unrestricted long-term operation
Zone C
Warning 		7.5 - 11.8 Unsatisfactory for long-term continuous operation
Zone D
Danger 		11.8+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 3.8 Boundary between Zone A and Zone B
B/C 7.5 Boundary between Zone B and Zone C
C/D 11.8 Boundary between Zone C and Zone D

Machine: gas turbine

Speed Range: 3000 or 3600 shaft rotational speed

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 4.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		4.5 - 9.3 Acceptable for unrestricted long-term operation
Zone C
Warning 		9.3 - 14.7 Unsatisfactory for long-term continuous operation
Zone D
Danger 		14.7+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 4.5 Boundary between Zone A and Zone B
B/C 9.3 Boundary between Zone B and Zone C
C/D 14.7 Boundary between Zone C and Zone D
view_module Vibration of rotating shafts
Measurement: Peak-To-Peak Displacement

warning Values required but not provided in this table

description ISO 20816-3

Critical Machines

Industrial machinery with a power rating above 15 kW and operating speeds between 120 r/min and 30000 r/min

speed Measurement: Rms Velocity Mm Per Second
group Group 1

Support Class: Rigid

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2.3 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2.3 - 4.5 Acceptable for unrestricted long-term operation
Zone C
Warning 		4.5 - 7.1 Unsatisfactory for long-term continuous operation
Zone D
Danger 		7.1+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2.3 Boundary between Zone A and Zone B
B/C 4.5 Boundary between Zone B and Zone C
C/D 7.1 Boundary between Zone C and Zone D

info Large machines with rated power above 300kW and not more than 50MW

Support Class: Flexible

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 3.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		3.5 - 7.1 Acceptable for unrestricted long-term operation
Zone C
Warning 		7.1 - 11.0 Unsatisfactory for long-term continuous operation
Zone D
Danger 		11.0+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 3.5 Boundary between Zone A and Zone B
B/C 7.1 Boundary between Zone B and Zone C
C/D 11.0 Boundary between Zone C and Zone D

info Large machines with rated power above 300kW and not more than 50MW

group Group 2

Support Class: Rigid

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 1.4 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		1.4 - 2.8 Acceptable for unrestricted long-term operation
Zone C
Warning 		2.8 - 4.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		4.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 1.4 Boundary between Zone A and Zone B
B/C 2.8 Boundary between Zone B and Zone C
C/D 4.5 Boundary between Zone C and Zone D

info Medium-sized machines with rated power above 15kW up to and including 300kW

Support Class: Flexible

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2.3 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2.3 - 4.5 Acceptable for unrestricted long-term operation
Zone C
Warning 		4.5 - 7.1 Unsatisfactory for long-term continuous operation
Zone D
Danger 		7.1+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2.3 Boundary between Zone A and Zone B
B/C 4.5 Boundary between Zone B and Zone C
C/D 7.1 Boundary between Zone C and Zone D

info Medium-sized machines with rated power above 15kW up to and including 300kW

description ISO 20816-4

Gas turbines

Gas turbines in excess of 3 MW, with fluid-film bearings

view_module Vibration of non-rotating parts
Measurement: Rms Velocity Mm Per Second

Location: bearing housing or pedestal

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 4.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		4.5 - 9.3 Acceptable for unrestricted long-term operation
Zone C
Warning 		9.3 - 14.7 Unsatisfactory for long-term continuous operation
Zone D
Danger 		14.7+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 4.5 Boundary between Zone A and Zone B
B/C 9.3 Boundary between Zone B and Zone C
C/D 14.7 Boundary between Zone C and Zone D
view_module Vibration of rotating shafts
Measurement: Peak-To-Peak Displacement

warning Values required but not provided in this table

description ISO 10816-1:1995

General guidelines

speed Measurement: Rms Velocity Mm Per Second
class Class 1
bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 0.71 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		0.71 - 1.8 Acceptable for unrestricted long-term operation
Zone C
Warning 		1.8 - 4.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		4.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 0.71 Boundary between Zone A and Zone B
B/C 1.8 Boundary between Zone B and Zone C
C/D 4.5 Boundary between Zone C and Zone D

info Individual parts of engines and machines, integrally connected to the complete machine in its normal operating condition. (Production electrical motors of up to 15 kW are typical examples of machines in this category.)

class Class 2
bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 1.12 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		1.12 - 2.8 Acceptable for unrestricted long-term operation
Zone C
Warning 		2.8 - 7.1 Unsatisfactory for long-term continuous operation
Zone D
Danger 		7.1+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 1.12 Boundary between Zone A and Zone B
B/C 2.8 Boundary between Zone B and Zone C
C/D 7.1 Boundary between Zone C and Zone D

info Medium-sized machines (typically electrical motors with 15 kW to 75 kW output) without special foundations, rigidly mounted engines or machines (up to 300 kW) on special foundations.

class Class 3
bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 1.8 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		1.8 - 4.5 Acceptable for unrestricted long-term operation
Zone C
Warning 		4.5 - 11.2 Unsatisfactory for long-term continuous operation
Zone D
Danger 		11.2+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 1.8 Boundary between Zone A and Zone B
B/C 4.5 Boundary between Zone B and Zone C
C/D 11.2 Boundary between Zone C and Zone D

info Large prime-movers and other large machines with rotating masses mounted on rigid and heavy foundations which are relatively stiff in the direction of vibration measurements.

class Class 4
bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2.8 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2.8 - 7.1 Acceptable for unrestricted long-term operation
Zone C
Warning 		7.1 - 18.0 Unsatisfactory for long-term continuous operation
Zone D
Danger 		18.0+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2.8 Boundary between Zone A and Zone B
B/C 7.1 Boundary between Zone B and Zone C
C/D 18.0 Boundary between Zone C and Zone D

info Large prime-movers and other large machines with rotating masses mounted on foundations which are relatively soft in the direction of vibration measurements (for example, turbogenerator sets and gas turbines with outputs greater than 10 MV).

description ISO 10816-1:2009

General guidelines

speed Measurement: Rms Velocity Mm Per Second
tune Vibration Limits Range

info Note: This standard provides a range of values. The actual limits depend on machine type and size.

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 4.5 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		4.5 - 9.3 Acceptable for unrestricted long-term operation
Zone C
Warning 		9.3 - 14.7 Unsatisfactory for long-term continuous operation
Zone D
Danger 		14.7+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 4.5 Boundary between Zone A and Zone B
B/C 9.3 Boundary between Zone B and Zone C
C/D 14.7 Boundary between Zone C and Zone D

info This table only applies to machines for which specific parts of ISO 10816 have not been developed and for which there is no past satisfactory experience available. Small machines (e.g. electric motors with power up to 15 kW) tend to lie at the lower end of the range and larger machines (e.g. prime movers with flexible supports in the direction of measurement) tend to lie at the upper end of the range.

description ISO 20816-8:2018

Reciprocating compressor systems

Reciprocating compressor systems with diesel engines

view_module Vibration of non-rotating parts
settings Compressor Type: Horizontal Compressors Measurement: Rms Velocity Mm Per Second

Location: Foundation

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2 - 3 Acceptable for unrestricted long-term operation
Zone C
Warning 		3 - 4.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		4.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2 Boundary between Zone A and Zone B
B/C 3 Boundary between Zone B and Zone C
C/D 4.5 Boundary between Zone C and Zone D

Location: Frame top

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 5.3 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		5.3 - 8 Acceptable for unrestricted long-term operation
Zone C
Warning 		8 - 12 Unsatisfactory for long-term continuous operation
Zone D
Danger 		12+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 5.3 Boundary between Zone A and Zone B
B/C 8 Boundary between Zone B and Zone C
C/D 12 Boundary between Zone C and Zone D

Location: Cylinder lateral

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 8.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		8.7 - 13 Acceptable for unrestricted long-term operation
Zone C
Warning 		13 - 19.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		19.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 8.7 Boundary between Zone A and Zone B
B/C 13 Boundary between Zone B and Zone C
C/D 19.5 Boundary between Zone C and Zone D

Location: Cylinder rod

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 10.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		10.7 - 16 Acceptable for unrestricted long-term operation
Zone C
Warning 		16 - 24 Unsatisfactory for long-term continuous operation
Zone D
Danger 		24+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 10.7 Boundary between Zone A and Zone B
B/C 16 Boundary between Zone B and Zone C
C/D 24 Boundary between Zone C and Zone D

Location: Dampers

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 12.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		12.7 - 19 Acceptable for unrestricted long-term operation
Zone C
Warning 		19 - 28.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		28.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 12.7 Boundary between Zone A and Zone B
B/C 19 Boundary between Zone B and Zone C
C/D 28.5 Boundary between Zone C and Zone D

Location: Mainline piping

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 12.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		12.7 - 19 Acceptable for unrestricted long-term operation
Zone C
Warning 		19 - 28.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		28.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 12.7 Boundary between Zone A and Zone B
B/C 19 Boundary between Zone B and Zone C
C/D 28.5 Boundary between Zone C and Zone D
view_module Vibration of non-rotating parts
settings Compressor Type: Vertical Compressors Measurement: Rms Velocity Mm Per Second

Location: Foundation

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 2 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		2 - 3 Acceptable for unrestricted long-term operation
Zone C
Warning 		3 - 4.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		4.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 2 Boundary between Zone A and Zone B
B/C 3 Boundary between Zone B and Zone C
C/D 4.5 Boundary between Zone C and Zone D

Location: Frame top

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 5.3 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		5.3 - 8 Acceptable for unrestricted long-term operation
Zone C
Warning 		8 - 12 Unsatisfactory for long-term continuous operation
Zone D
Danger 		12+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 5.3 Boundary between Zone A and Zone B
B/C 8 Boundary between Zone B and Zone C
C/D 12 Boundary between Zone C and Zone D

Location: Cylinder lateral

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 10.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		10.7 - 16 Acceptable for unrestricted long-term operation
Zone C
Warning 		16 - 24 Unsatisfactory for long-term continuous operation
Zone D
Danger 		24+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 10.7 Boundary between Zone A and Zone B
B/C 16 Boundary between Zone B and Zone C
C/D 24 Boundary between Zone C and Zone D

Location: Cylinder rod

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 8.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		8.7 - 13 Acceptable for unrestricted long-term operation
Zone C
Warning 		13 - 19.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		19.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 8.7 Boundary between Zone A and Zone B
B/C 13 Boundary between Zone B and Zone C
C/D 19.5 Boundary between Zone C and Zone D

Location: Dampers

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 12.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		12.7 - 19 Acceptable for unrestricted long-term operation
Zone C
Warning 		19 - 28.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		28.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 12.7 Boundary between Zone A and Zone B
B/C 19 Boundary between Zone B and Zone C
C/D 28.5 Boundary between Zone C and Zone D

Location: Mainline piping

bar_chart Vibration Zones Visualization
Zone A (Healthy)
Zone B (Healthy)
Zone C (Warning)
Zone D (Dangerous)
A/B
B/C
C/D
Zone Range (mm/s) Description
Zone A
Healthy 		0 - 12.7 Newly commissioned machines normally fall within this zone
Zone B
Healthy 		12.7 - 19 Acceptable for unrestricted long-term operation
Zone C
Warning 		19 - 28.5 Unsatisfactory for long-term continuous operation
Zone D
Danger 		28.5+ Sufficient severity to cause damage to the machine

Threshold Boundaries:

Boundary Value (mm/s) Meaning
A/B 12.7 Boundary between Zone A and Zone B
B/C 19 Boundary between Zone B and Zone C
C/D 28.5 Boundary between Zone C and Zone D
legend_toggle ISO Vibration Zone Definitions
Zone A

Zone A: Healthy

The vibration of newly commissioned machines normally falls within this zone.

Zone B

Zone B: Healthy

Machines with vibration within this zone are normally considered acceptable for unrestricted long-term operation.

Zone C

Zone C: Warning

Machines with vibration within this zone are normally considered unsatisfactory for long-term continuous operation.

Zone D

Zone D: Danger

Vibration values within this zone are normally considered to be of sufficient severity to cause damage to the machine.

Note: The boundaries A/B, B/C, and C/D represent threshold values between zones. Values are in mm/s (RMS velocity) unless otherwise specified.