Valve
Live Loading
With
Belleville
Springs®
Belleville Springs for Valve Live Loading
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?
Belleville
Named for Julian F. Belleville who received a
British patent in the 1860’s..
(It was on a valve application)
Belleville Springs, Belleville Disc Springs, Disc Springs
and Conical Compression Washers
are all names for the same type of spring.
Belleville Springs for Valve Live Loading
Typical Belleville Spring
OD
h H
ID
Comprised of 5 main components
Outside Diameter Inside Diameter
Material Thickness Overall Height
Deflection or Movement
Belleville Springs for Valve Live Loading
Single Belleville Spring
1500 lb. Flat Load
(Example)
1500
1250
1000
750
500
0
0 10 15 20
Belleville Springs for Valve Live Loading
Belleville Spring
with
1500lb/689kg Flat Load
No
Load 33% 66% Flat
0lbs/0kg 500lbs/227kg 1000lbs/454kg 1500lbs/680kg
Belleville Springs for Valve Live Loading
Stacking Arrangements
of Solon Belleville Springs
Single Parallel
Series Parallel / Series
Belleville Springs for Valve Live Loading
Deflection Chart
1250
1000
Load
750
500
250
0
0 20 40 60
Deflection
Belleville Springs for Valve Live Loading
Which Valves Are Candidates
For Live Loading?
Frequently Cycled Valves
Operated Valves (Air or Motor)
Critical Applications
Safety or Difficult Location
History of Packing Leaks
Monitored Valves
Belleville Springs for Valve Live Loading
Reasons For Valve Leaks?
Wrong Packing for the Application
Bent, Scored, or Pitted Valve Stems
Improper Packing Installation
Infrequent Use
Frequent or High Cycles
Loss Of Packing Load
Belleville Springs for Valve Live Loading
How Live Loading Works
34.5
Packing Compressive Stress (MPa)
Packing Compressive Stress (PSI)
5000 With
Live Load
3000 20.7
Without
Live Load
0 5 10
In - Service Consolidation (%)
Belleville Springs for Valve Live Loading
Retightening Vs Live Loading
Packing Pressure
Leakage
Threshold Loss Of Torque Leads To Leakage
Years 1 2 3 4 5 6
No Live Load Live Load
Gland Nuts Springs Maintain
Re-tightened Packing Pressure
Belleville Springs for Valve Live Loading
Basic Formula For Calculating
Valve Live Loading
Required = A x P
Bolt Load
B
A = Packing Area
P = 1.5 x System Pressure or Manufacturers Load Factor
(Whichever is greater)
B = Number of Gland Bolts
Torque .2 x Bolt Load x Bolt Diameter
(Ft. Lbs.)
=
12
Formula based on 5 ring graphite set (EPRI)
Belleville Springs for Valve Live Loading
Selecting the Proper Spring Material
Operating Environment & Temperature
17-7PH – Most Widely Used
Good for most environments except Chloride & Fluorides (Unless
plated) -400 F / -240 C to 550 F / 288 C
301 SS – Limited Size Range
-400ºF/-240ºC to 550ºF/288ºC
Inconel 718 – Higher Cost
High Temperatures & Corrosives -400F / -240C to 1100F / 593 C
6150 Alloy – Needs to be plated for outdoor use
-40ºF/-40ºC to 350ºF/177ºC
H-13 Tool Steel – High Temp
Ambient to 1100F / 593C
Belleville Springs for Valve Live Loading
Selecting the Proper Spring Material
Spring Load vs Material
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.
Belleville Springs for Valve Live Loading
Factors in Selecting a Belleville Spring
Material
Temperature
Environment
Corrosives
Coatings
Size Constraints
OD, ID, Height of spring stack
Load
Usually select a spring with a flat load
20% higher than the preload
Belleville Springs for Valve Live Loading
Typical Installation of
Solon Belleville Springs
Belleville Springs for Valve Live Loading
Alternate Installations
Belleville Springs for Valve Live Loading
Alternate Installations
Belleville Springs for Valve Live Loading
Alternate Installations
Belleville Springs for Valve Live Loading
Sleeves No Sleeves
Belleville Springs for Valve Live Loading
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
Spring Thickness Is Less
Than The Stud Thread Root
Sleeve Is Used To Measure
Relaxation In Packing
(Usually Done With External Sleeve)
Belleville Springs for Valve Live Loading
Other Live Loaded Areas
Live Loaded Bonnet
Belleville
Spring
Belleville Springs for Valve Live Loading
Other Live Loaded Areas
Live Loaded Ball Seat
Belleville
Spring
Belleville Springs for Valve Live Loading
Typical Live Loading Information General Information
Stem Dia.* Customer
Stuffing Box Dia.* Unit
Live Stuffing Box Depth*
Stud Dia.*
No. of Studs*
System Temp.*
System
Valve Mfg.
Valve Size
Valve Class
Valve Type
System Pressure*
Loading Packing Type*
Available Stud Length
No. of Packing Rings
Packing Load
Serial No.
Tag No.
Location
Position
Operated
Packing Torque
In-Service Consolidation
Bushing Hgt Flange Information
Survey * Req’d For Live Loading Calculations
Spring Information
No. of Studs
Stud Dia.
Gasket Type
Gasket Size
Sheet
Solon Part No. Gasket No.
No of Springs / Stud Torque
Spring Configuration Solon Part No.
Bonnet Information
No. of Studs
Stud Dia.
Gasket Type
Gasket Size
Gasket No.
Torque
Solon Part No.
Belleville Springs for Valve Live Loading
Thank you!
Solon Manufacturing Co.
George Davet, Chief Engineer
gdavet@solonmfg.com
800-323-9717
OD
h H
ID
Belleville Springs for Valve Live Loading
