Belleville Springs for Valve Live Loading

Transcription

Valve
Live Loading
With
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’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.
Typical Belleville Spring
OD
h
ID
Comprised of 5 main components
Outside Diameter
Inside Diameter
Material Thickness
Overall Height
Deflection or Movement
H
Single Belleville Spring
1500 lb. Flat Load
(Example)
1500
1250
1000
750
500
0
0
10
15
20
Belleville Spring
with
1500lb/689kg Flat Load
No
Load
0lbs/0kg
33%
500lbs/227kg
66%
1000lbs/454kg
Flat
1500lbs/680kg
Stacking Arrangements
of Solon Belleville Springs
Single
Series
Parallel
Parallel / Series
Deflection Chart
1250
Load
1000
750
500
250
0
0
20
40
60
Deflection
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
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
34.5
5000
With
Live Load
3000
20.7
Without
Live Load
0
5
10
In - Service Consolidation (%)
Packing Compressive Stress (MPa)
Packing Compressive Stress (PSI)
How Live Loading Works
Packing Pressure
Retightening Vs Live Loading
Leakage
Threshold
Years 1
Loss Of Torque Leads To Leakage
2
No Live Load
Gland Nuts
Re-tightened
3
4
5
6
Live Load
Springs Maintain
Packing Pressure
Basic Formula For Calculating
Valve Live Loading
Required
Bolt Load
=
A x P
B
A = Packing Area
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
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
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.
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
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
Sleeve Is Used To Measure
Relaxation In Packing
(Usually Done With External Sleeve)
Other Live Loaded Areas
Live Loaded Bonnet
Belleville
Spring
Other Live Loaded Areas
Live Loaded Ball Seat
Belleville
Spring
Typical
Live
Loading
Survey
Sheet
Live Loading Information
Stem Dia.*
Stuffing Box Dia.*
Stuffing Box Depth*
Stud Dia.*
No. of Studs*
System Temp.*
System Pressure*
Packing Type*
Available Stud Length
No. of Packing Rings
Packing Load
Packing Torque
In-Service Consolidation
Bushing Hgt
General Information
Customer
Unit
System
Valve Mfg.
Valve Size
Valve Class
Valve Type
Serial No.
Tag No.
Location
Position
Operated
Flange Information
* Req’d For Live Loading Calculations
Spring Information
Solon Part No.
No of Springs / Stud
Spring Configuration
No. of Studs
Stud Dia.
Gasket Type
Gasket Size
Gasket No.
Torque
Solon Part No.
Bonnet Information
No. of Studs
Stud Dia.
Gasket Type
Gasket Size
Gasket No.
Torque
Solon Part No.
Thank you!
Solon Manufacturing Co.
George Davet, Chief Engineer
[email protected]
800-323-9717
OD
h
ID
H

Belleville Springs for Valve Live Loading

Transcription

Similar documents

Lower Breitenbush Hot Springs Visioning

The Triplets Of Belleville The Triplets of Belleville (2003) is a film wr

Jr Lancers - Belleville East Sports

Belleville Spring

Providence at Harbour Club

11011 ANAQUA SPRINGS | Anaqua Springs Ranch

View Dr van Niekerk`s presentation

Winterfest Wine Tasting 2016 Flyer

PV0003 Data Sheet

Welcome Picnic at Ginnie Springs

Moog® EXCLUSIVE BELLEVILLE WaShEr DESIgn - Fme-Cat