Valve Live Loading With Belleville Springs · Belleville. NamedNamedfor Julian F. Belleville who...

ValveLive Loading

With

Belleville Springs for Valve Live Loading

WithBellevilleSprings®

Valve Live Loading With Solon Belleville Springs

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.


What is 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, 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


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


0 10 15 200

500

750

1000

1250

1500

Belleville Spring with

1500lb/689kg Flat Load

NoLoad 33% 66% Flat


Load

0lbs/0kg

33%

500lbs/227kg

66%

1000lbs/454kg 1500lbs/680kg

Flat

Stacking Arrangementsof Solon Belleville Springs

Single Parallel


Single

Series

Parallel

Parallel / Series

Deflection Chart

750

1000

1250Lo

ad


Deflection

0 20 40 600

250

500

Which Valves Are Candidates For Live Loading?

Frequently Cycled Valves

Operated Valves (Air or Motor)

Critical Applications


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


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


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


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


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


-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


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


Size ConstraintsOD, ID, Height of spring stack

LoadUsually select a spring with a flat load

20% higher than the preload

Typical Installation of Solon Belleville Springs


Alternate Installations


Sleeves No Sleeves


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

(Usually Done With External Sleeve)

Sleeve Is Used To Measure Relaxation In Packing

Other Live Loaded Areas

Live Loaded Bonnet

Belleville


Spring

Other Live Loaded AreasLive Loaded Ball Seat

Belleville


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


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

[email protected]

800-323-9717


OD

ID

Hh

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