Valve Live Loading With Belleville Springs for Valve Live Loading With Belleville Springs ®
ValveLive Loading
With
Belleville Springs for Valve Live Loading
WithBellevilleSprings®
What is Valve Live Loading?The addition of Belleville
Springs to the gland follower studs to maintain the
packing load of the valve over time.
Belleville Springs for Valve Live Loading
What’s In The Name?BellevilleBelleville
NamedNamed for Julian F. Belleville who received a British patent in the 1860’s. .
(It was on a valve application)(It was on a valve application)
Belleville Springs for Valve Live Loading
Belleville Springs, Belleville Disc Springs, Disc Springs and Conical Compression Washers
are all names for the same type of spring.
(It was on a valve application)(It was on a valve application)
Typical Belleville Spring
OD
Hh
Belleville Springs for Valve Live Loading
ID
Comprised of 5 main components
Outside Diameter Inside Diameter Material Thickness Overall Height
Deflection or Movement
Single Belleville Spring
1500 lb. Flat Load
(Example)
1500
Belleville Springs for Valve Live Loading
0 10 15 200
500
750
1000
1250
1500
Belleville Spring with
1500lb/689kg Flat Load
NoLoad 33% 66% Flat
Belleville Springs for Valve Live Loading
Load
0lbs/0kg
33%
500lbs/227kg
66%
1000lbs/454kg 1500lbs/680kg
Flat
Stacking Arrangementsof Solon Belleville Springs
Single Parallel
Belleville Springs for Valve Live Loading
Single
Series
Parallel
Parallel / Series
Deflection Chart
750
1000
1250Lo
ad
Belleville Springs for Valve Live Loading
Deflection
0 20 40 600
250
500
Which Valves Are Candidates For Live Loading?
Frequently Cycled Valves
Operated Valves (Air or Motor)
Critical Applications
Belleville Springs for Valve Live Loading
Critical Applications
Safety or Difficult Location
History of Packing Leaks
Monitored Valves
Reasons For Valve Leaks?
Wrong Packing for the Application
Bent, Scored, or Pitted Valve Stems
Improper Packing Installation
Infrequent Use
Belleville Springs for Valve Live Loading
Infrequent Use
Frequent or High Cycles
Loss Of Packing Load
Co
mp
ress
ive
Str
ess
(PS
I)
Pac
kin
g C
om
pre
ssiv
e S
tres
s(M
Pa)
5000
3000
34.5
20.7
How Live Loading WorksHow Live Loading WorksHow Live Loading WorksHow Live Loading Works
With
Live Load
Belleville Springs for Valve Live Loading
In - Service Consolidation (%)
Pac
kin
g C
om
pre
ssiv
e
Pac
kin
g C
om
pre
ssiv
e
5 100
Without
Live Load
Pac
kin
gP
ress
ure
Retightening Vs Live LoadingRetightening Vs Live LoadingRetightening Vs Live LoadingRetightening Vs Live Loading
Belleville Springs for Valve Live Loading
Springs MaintainPacking Pressure
Gland NutsRe-tightened
Pac
kin
g
543 61 2
Loss Of Torque Leads To Leakage
Years
Live LoadNo Live Load
Leakage
Threshold
Basic Formula For CalculatingBasic Formula For CalculatingBasic Formula For CalculatingBasic Formula For CalculatingValve Live Loading Valve Live Loading Valve Live Loading Valve Live Loading
A = Packing Area
P = 1.5 x System Pressure or Manufacturers Load Factor
=RequiredBolt Load
A x P
B
Belleville Springs for Valve Live Loading
P = 1.5 x System Pressure or Manufacturers Load Factor(Whichever is greater)
B = Number of Gland Bolts
Torque(Ft. Lbs.) =
.2 x Bolt Load x Bolt Diameter
12
Formula based on 5 ring graphite set (EPRI)
Selecting the Proper Spring Material Selecting the Proper Spring Material Selecting the Proper Spring Material Selecting the Proper Spring Material Operating Environment & Temperature
Good for most environments except Chloride & Fluorides (Unless plated) -400 F / -240 C to 550 F / 288 C
-400ºF/-240ºC to 550ºF/288ºC
17-7PH – Most Widely Used17-7PH – Most Widely Used
301 SS – Limited Size Range301 SS – Limited Size Range
Inconel 718 – Higher CostInconel 718 – Higher Cost
Belleville Springs for Valve Live Loading
-40ºF/-40ºC to 350ºF/177ºC
6150 Alloy – Needs to be plated for outdoor use6150 Alloy – Needs to be plated for outdoor use
Inconel 718 – Higher CostInconel 718 – Higher CostHigh Temperatures & Corrosives -400F / -240C to 1100F / 593 C
H-13 Tool Steel – High TempH-13 Tool Steel – High TempAmbient to 1100F / 593C
Selecting the Proper Spring Material Selecting the Proper Spring Material Selecting the Proper Spring Material Selecting the Proper Spring Material
Spring Load vs Material
It is important to note when selecting a Belleville
Belleville Springs for Valve Live Loading
It is important to note when selecting a Belleville
spring that the same size part made with a different
material may have a different flat load.
Factors in Selecting a Belleville Spring Factors in Selecting a Belleville Spring Factors in Selecting a Belleville Spring Factors in Selecting a Belleville Spring
MaterialTemperature
Environment
Coatings
Corrosives
Size Constraints
Belleville Springs for Valve Live Loading
Size ConstraintsOD, ID, Height of spring stack
LoadUsually select a spring with a flat load
20% higher than the preload
Why Sleeves Are Used
I.D. Of Spring Is Too Large For The Gland Stud
Metric Springs Used With Inch Studs
Sleeve Is Used To Limit Torque
Belleville Springs for Valve Live Loading
Spring Thickness Is Less Than The Stud Thread Root
(Usually Done With External Sleeve)
Sleeve Is Used To Measure Relaxation In Packing
Other Live Loaded Areas
Live Loaded Bonnet
Belleville
Belleville Springs for Valve Live Loading
Spring
Other Live Loaded AreasLive Loaded Ball Seat
Belleville
Belleville Springs for Valve Live Loading
Belleville Spring
Live Loading Information
Stem Dia.Stuffing Box Dia.Stuffing Box DepthStud Dia.No. of StudsSystem Temp.System PressurePacking TypeAvailable Stud LengthNo. of Packing RingsPacking LoadPacking TorqueIn-Service Consolidation
***
***
**
General Information
CustomerUnitSystemValve Mfg.Valve SizeValve ClassValve TypeSerial No.Tag No.LocationPositionOperated
Typical
Live Loading
Belleville Springs for Valve Live Loading
In-Service ConsolidationBushing Hgt
Bonnet Information
No. of StudsStud Dia.Gasket TypeGasket SizeGasket No.TorqueSolon Part No.
Flange Information
No. of StudsStud Dia.Gasket TypeGasket SizeGasket No.TorqueSolon Part No.
Spring Information
Solon Part No.No of Springs / StudSpring Configuration
* Req’d For Live Loading CalculationsSurvey Sheet
Thank you!
Solon Manufacturing Co. George Davet, Chief Engineer
800-323-9717
Belleville Springs for Valve Live Loading
OD
ID
Hh