Additional Resources > Windchill Risk and Reliability Practitioner’s Guide > Data Tables > Mechanical Devices
Mechanical Devices
Table A-56 provides information for mechanical devices.
Table A-56. Mechanical Items - Base Failure Rates, Environmental Factors and Failure Mode Data
Non- operational
Item Description
Operational
Base Failure Rate λb failures 106 hrs
Base Failure Rate λb failures 106 hrs
Environmental Factors ( KE )
Predominant Failure Modes
GFP
G.1
G.2
S.1
S.2
A.1
A.2
Mode
% Factor
Ground Fixed Protected
Ground Fixed
Ground Mobile
Ship Protected
Ship Exposed
Air Protected
Air Exposed
0.53
Accumulator, Hydraulic
35.0
1.5
1.3
1.5
2.0
4.5
0.29
Actuator, Hydraulic
15.0
3.5
3.3
3.5
6.0
8.0
0.06
Actuator, Pneumatic
15.0
5.5
2.5
7.5
5.0
8.0
1.2
Barometric Capsule
1.2
N/A
N/A
N/A
2.0
4.0
Distortion
50
Porosity
50
0.1
Bearing, Ball, Light Duty
2.3
3.0
2.0
3.0
2.0
4.0
Lubrication Failure
45
Contamination
25
0.04
Bearing, Ball, Heavy Duty
4.5
2.2
1.2
2.2
1.5
3.2
Lubrication Failure
45
Contamination
25
0.002
Bearing, Jewel
0.4
3.0
1.3
3.0
2.0
4.0
Contamination
60
Distortion
20
Lubrication
12
0.005
Bearing, Rotary, Roller
1.2
3.0
2.5
3.0
2.2
3.5
0.005
Bearing, Rotary, Sleeve
3.0
7.0
3.0
7.0
8.0
10.0
0.0005
Bearing, Spherical
1.0
5.0
3.0
5.0
6.4
l0.0
0.0002
Bearing, Translatory, Sleeve
0.2
6.0
2.3
6.0
5.0
l0.0
0.0005
Bearing, Bush
0.4
6.0
2.3
6.0
5.0
10.0
1.0
Bellows
9.5
5.0
4.0
5.0
10.0
12.0
0.0002
Bracket, Mounting
0.1
4.0
1.5
4.0
2.0
6.0
0.01
Brake Assembly, Mechanical, Friction
1.5
3.0
1.3
3.0
2.0
3.0
0.0001
Cam and Follower
1.8
5.0
1.2
5.0
1.5
6.0
Lubrication Faults
33
Adhesive Bond
27
Failure Distortion
33
Carburetor
0.0005
Clutch, Dog
0.5
3.0
2.7
3.0
6.0
9.0
0.05
Clutch, Friction
3.5
6.2
2.6
6.0
4.0
8.0
Contamination Lubrication
20
Failure
15
Mechanical Degradation
50
0.005
Clutch, Magnetic
5.0
3.0
2.0
3.0
4.0
5.0
0.05
Clutch, Slip
2.4
6.0
2.0
6.0
4.0
7.0
0.0001
Connections, Hydraulic
0.35
2.5
1.5
3.0
3.5
4.3
0.0001
Connections, Pneumatic
0.4
2.5
1.5
3.0
3.5
5.0
0.05
Counter, Mechanical
2.0
5.0
2.0
5.0
4.0
5.0
Lubrication Failure
58
Contamination
21
0.004
Coupling, Flexible Drive
1.25
5.0
4.0
5.0
10.0
13.0
0.002
Coupling,
Rotary Shaft
0.2
2.0
1.3
2.0
2.0
3.0
Diaphragm, Metal
5.0
6.0
Diaphragm, Rubber
8.0
Drive, Belt
34.0
5.3
Drive, Cable
3.2
6.0
Drive, Constant Speed
(Pneumatic)
20.0
7.0
Drive, Pulley
1.3
6.0
Duct
2.0
12.0
0.0001
Filter, Fuel
3.0
11.0
0.0001
Filter, Hydraulic Fluid
3.25
8.0
0.001
Filter, Pneumatic
1.5
6.5
0.01
Gasket, Cork
0.5
6.5
0.01
Gasket, Paper
1.0
6.8
0.01
Gasket, Monel Mesh
0.4
6.25
0.01
Gasket, 0 Ring
0.16
2.0
1.5
2.0
2.5
6.25
Deterioration
90
0.01
Gasket, Phenolic
0.4
6.25
0.01
Gasket, Rubber
0.16
6.25
Deterioration
65
0.05
Gauge Pressure (Bourden Tube)
9.5
2.0
1.5
2.0
2.0
2. 4
Mesh
0.03
4.0
2.7
4.0
6.0
Contamination
21
Mechanical Failure
21
Misalignment
29
Lubrication Inadequate
29
Gear Train, Anti-Backlash, per Mesh
1.0
3.0
2.0
3.0
4.0
Gear Box
12.0
2.5
Heat Exchanger
0.9
4.0
1.8
2.0
1.2
3.5
0.001
Hose, Heavy Stress
25.0
4.0
Deterioration
85
End Fitting Failure
10
0.005
Hose, Flexible
1.5
2.2
Deterioration
85
End Fitting Failure
10
0.005
Hose, Pneumatic
10.0
15.0
Deterioration
85
End Fitting Failure
10
Hose, Coolant (I.C. Engine)
22.0
N/A
N/A
Deterioration
85
Insert, Wire, Screwthread
0.1
0.01
Jack, Hydraulic
0.18
Motor, Hydraulic Mount,
Anti-Vibration
5.0
8.0
2.7
8.0
10.0
0.0001
Mirror
0.1
3.0
2.0
3.0
4.0
Plugs, Spark,
I.C. Engine
0.18
Pump, Engine Driven, Hydraulic
8.0
5.0
2.0
5.0
4.0
10.0
0.06
Pump, Fuel, Engine Driven
12.0
2.0
1.5
2.0
2.5
3.0
Pump, Vacuum, Engine Driven
9.0
2.0
1.5
2.0
5.0
6.0
0.002
Piston, Hydraulic
1.3
5.0
2.0
5.0
4.0
6.0
0.0004
Prism
0.4
3.90
2.0
3.0
4.0
0.003
Radome
8.0
2.0
N/A
2.0
N/A
3.0
0.01
Reducer, Pneumatic Pressure
0.3
2.0
1.5
2.0
2.5
3.0
0.01
Regulator, Hydraulic Pressure
2.3
3.0
2.0
3.0
4.0
5.0
0.01
Reservoir, Hydraulic
2.4
3.0
2.0
3.0
4.0
5.0
Seal, Sliding
3.0
3.0
2.0
3.0
3.5
6.25
0.01
Seal, 0 Ring
0.16
2.0
1.5
2.0
2.5
3.0
Seal, Rotating
7.0
3.0
2.0
3.0
3.5
5.0
Strip, Bonded
0.09
2.0
1.5
2.0
2.5
3.0
Shaft, Gear, Extension
0.35
2.0
1.5
2.0
2.5
3.0
Spring, Calibration, Sensitive
2.0
4.0
2.3
4.0
5.0
6.0
Distortion
30
Fracture
67
Return Force
0.32
3. 0
1.5
3.0
2.5
3.0
Distortion
30
I.C. Engine
9.6
1.5
1.0
1.5
N/A
N/A
Distortion
30
Fracture
67
Tank, Fuel, Integral (Wing)
13.0
N/A
N/A
N/A
N/A
10.0
0.24
Tank, Small, SP
2.0
2.0
0.24
Tank, Small, LP
1.5
2.0
0.05
Timer, Mechanical
2.0
5.0
2.7
5.0
6.0
7.0
Valve, Air
1.7
3.0
4.0
5.0
4.0
6.0
0.17
Valve, Butterfly
1.32
Valve, Filler and Charging (Gas)
0.9
3.0
2.0
4.0
4.0
6.0
Valve, Float, Fuel
15.0
2.0
1.5
2.0
3.0
4.0
0.24
Valve, Fuel, Check
1.3
1.4
1.25
1.4
2.2
3.0
0.28
Valve, Hydraulic, Ball
0.6
2.3
0.002
Valve, Hydraulic, Check
2.0
6.0
0.005
Valve, Hydraulic, Control
0.01
Valve, Hydraulic, Pressure Regulator
3.5
2.4
8.0
0.002
Valve, Hydraulic, Relief
10.0
3.0
Valve Hydraulic, Restrictor
2.0
10.0
0.66
Valve, Hydraulic, Servo
48.0
3.3
Valve, Hydraulic, Shut-off
6.0
3.0
Valve, Hydraulic, Shuttle
9.0
6.0
Valve, Hydraulic, Spool
55.0
3.5
3.0
3.5
3.0
6.0
Valve, Pneumatic, Bleed
0.22
Valve, Pneumatic, Check
1.2
6.0
0.02
Valve, Pneumatic, Control
0.6
3.0
1.8
3.0
7.0
9.0
Valve, Pneumatic, Pressure Regulator
2.0
10.0
58.0
0.001
Valve, Pneumatic, Relief
1.6
2.5
6.0
10.0
17.0
31.0
Valve, Pneumatic, Selector
Valve, Pneumatic, Shut-off
52.0
1.4
2.0
0.03
Valve, Solenoid, General
6.4
3.0
1.7
3.0
3.0
4.0