thermal expansion in pipes

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Designing Systems to Compensate for Thermal Expansion and Contraction

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Page 1: Thermal Expansion in Pipes

Designing Systems

toCompensate

forThermal

Expansionand

Contraction

Page 2: Thermal Expansion in Pipes

Things We Have Learned From Being Sued

Page 3: Thermal Expansion in Pipes
Page 4: Thermal Expansion in Pipes
Page 5: Thermal Expansion in Pipes
Page 6: Thermal Expansion in Pipes
Page 7: Thermal Expansion in Pipes
Page 8: Thermal Expansion in Pipes
Page 9: Thermal Expansion in Pipes
Page 10: Thermal Expansion in Pipes
Page 11: Thermal Expansion in Pipes
Page 12: Thermal Expansion in Pipes
Page 13: Thermal Expansion in Pipes

6” Model MC - 6 CorrugationsAnchor Load @ 150psi - 11,600#

Page 14: Thermal Expansion in Pipes
Page 15: Thermal Expansion in Pipes
Page 16: Thermal Expansion in Pipes

This is why you should use guides

Page 17: Thermal Expansion in Pipes
Page 18: Thermal Expansion in Pipes
Page 19: Thermal Expansion in Pipes
Page 20: Thermal Expansion in Pipes

Riser F3 Floor 4‐25 Room 2‐4

Page 21: Thermal Expansion in Pipes
Page 22: Thermal Expansion in Pipes

Use Any Natural Flexibility In The piping layout

Page 23: Thermal Expansion in Pipes

2008 ASHRAE Handbook

Heating, Ventilating, and Air Conditioning Systems and Equipment

Chapter 45

Page 24: Thermal Expansion in Pipes

Or this can be simplified to

L = 6.225 √ΔD

L = 3ΔDE√(144in²/ft²)SA

Where Δ = Thermal expansion of leg ABD = Pipe Outside DiameterE = Modulus of ElasticitySA = Allowable Stress

For a Basic Expansion ElbowHard Pipe Δ

L

Anchor

Anchor

A

B

C

Page 25: Thermal Expansion in Pipes

L = 4 √ΔD Where Δ = Thermal expansion of leg ABD = Pipe Outside DiameterE = Modulus of ElasticitySA = Allowable Stress

For a Basic Expansion “Z” Bend Hard Pipe

X

X

Guide

Guide

AnchorAnchor

L

L

L

A

B

Anchor to Anchor Expansion

Page 26: Thermal Expansion in Pipes
Page 27: Thermal Expansion in Pipes
Page 28: Thermal Expansion in Pipes

So what kind of expansion joint to use?

Page 29: Thermal Expansion in Pipes

L = 6.225 √ΔD

W = L/5H = 2*W

Where Δ = Thermal expansion of runD = Pipe Outside DiameterE = Modulus of ElasticitySA = Allowable Stress

For a Basic Expansion Loop Hard Pipe

XX

AnchorAnchor

Guide

Guide

Anchor to Anchor Expansion

2H 2H

W

H

Page 30: Thermal Expansion in Pipes
Page 31: Thermal Expansion in Pipes

Hard Loops Pro/Con

Same material as the rest of piping

Constructed on site, costly to fabricate, hang and insulate

Grandfather used ‘em

Medium anchor loads

Constructed on site

Pro

Needs lots of room

High lateral loads on moment guides.

Con

Page 32: Thermal Expansion in Pipes

Flexible Expansion Loop

Page 33: Thermal Expansion in Pipes

“V” Loops

Page 34: Thermal Expansion in Pipes

The flexible pipe loop is also smaller and has less anchor load than a hard pipe loop

Page 35: Thermal Expansion in Pipes
Page 36: Thermal Expansion in Pipes

Hose Basics

Page 37: Thermal Expansion in Pipes

Corrugated stainless steel hose by itself

has great hoop strength, but poor tensile

strength

Page 38: Thermal Expansion in Pipes
Page 39: Thermal Expansion in Pipes
Page 40: Thermal Expansion in Pipes
Page 41: Thermal Expansion in Pipes

Virtually any amount of movement

Page 42: Thermal Expansion in Pipes

Cap weld,

welding the

hose, braid and

collar together

Page 43: Thermal Expansion in Pipes

Weld the End Fitting to the Hose

Page 44: Thermal Expansion in Pipes

On a flex loop the braid is the anchor

Page 45: Thermal Expansion in Pipes
Page 46: Thermal Expansion in Pipes
Page 47: Thermal Expansion in Pipes
Page 48: Thermal Expansion in Pipes

X

X

165

Feet

2.85

”Exp

.

50 Feet

.59” Exp.

19 F

eet

19 Feet

Guides

4” Sch 40 Carbon Steel With Hard Pipe Expansion 90

Anchor with 582 pounds force

X

X

165

Feet

2.85

”Exp

.50 Feet

.59” Exp.

3 Fe

et3 Feet

Guides

4” Sch 40 Carbon Steel With H&B Dog Leg

Anchor with 180 pounds force

Hose & Braid

Page 49: Thermal Expansion in Pipes
Page 50: Thermal Expansion in Pipes

Flexible Loop Pro/Con

Very compact Some pressure limitations

No maintenance

Minimal guiding requirements

Lowest anchor loads, almost no structural considerations.

Least expensive optionStandard or custom fit

Large movement

Seismic capable

Pro Con

Page 51: Thermal Expansion in Pipes

• Axial movement• Lateral movement• Angular movement

There’s a lot of choices of Bellows

Axial Bellows Externally Pressurized Axial Bellows

Untied Double Bellows Gimbal Bellows

Dual Tied BellowsDouble Hinged

BellowsSingle Hinge

Bellows

Page 52: Thermal Expansion in Pipes

Internally Pressurized

Externally Pressurized

Axial movement onlyCapable of Axial, Lateral and

Angular movements.

Page 53: Thermal Expansion in Pipes

Expansion

Compensators

externally

pressurized

Atmosphere

Built in Liner

Page 54: Thermal Expansion in Pipes

Squirm- Strut Instability - Limits the movement of internally pressurized bellows

The balance between the number of convolutions needed for the movement exceeds the stability of the bellows

Page 55: Thermal Expansion in Pipes
Page 56: Thermal Expansion in Pipes

Internally Pressurized Bellows

Axial

Are Primarily Designed to Handle

Axial Movement

Page 57: Thermal Expansion in Pipes

On the other hand,a dual-tied bellows moves

And laterally

Axially

Page 58: Thermal Expansion in Pipes

Dual-tied bellows joint

Page 59: Thermal Expansion in Pipes
Page 60: Thermal Expansion in Pipes

Anchors

Page 61: Thermal Expansion in Pipes

• Pressure ThrustPressure X effective area ( Use test pressure if greater )

Calculating forces on anchors

•Deflection Load –Published Spring Rate X movement of the joint

• Frictional ResistanceTotal weight of pipe, media, insulation & equip. X coefficient

Page 62: Thermal Expansion in Pipes

• Pressure ThrustPressure X effective area ( Use test pressure if greater )

• Example:4”= 35.96 sq. in effective area x 125 PSI = 4495 #.

Calculating forces on anchors

Page 63: Thermal Expansion in Pipes

To calculate the thrust load:Effective Areas

Page 64: Thermal Expansion in Pipes

Pressure Thrust for the Model MC Ring Controlled Self-Equalizing

Expansion Joint The average car weighs only

3000#

Page 65: Thermal Expansion in Pipes

Deflection Load (spring rate)

Totally independent of pressure or temperature

Page 66: Thermal Expansion in Pipes

• Published Spring Rate X Actual movement of the joint

• Example:4” with 6” Axial = Spring rate of 143 lbs/in

X4.3 (total amount of expansion)

= 614.9 lbs

Deflection Load on Anchors

Page 67: Thermal Expansion in Pipes

•Frictional ResistanceTotal weight of pipe, media, insulation & equip. X coeff.

•Example4” sch. 40 pipe at 10.8 #/ft x 75 ft = 1890 #

4” pipe internal area 12.73 sq.in. / 144 in. per sq.ft. = 0.088 cu.ft. x 175 linear ft. = 15.4 cu.ft. total volume

125 PSI steam = 3.23 cu.ft. per pound = 4.76# weightadd guides & joint & insulation at 500#

Total 2395# x 0.3 Coeff. = 719# frictional resistance

Calculating forces on anchors

Page 68: Thermal Expansion in Pipes

Total Anchor Force

4495 Pressure Thrust614 Deflection Load719 Friction Resistance5,828.9 lbs force

The engineer may add other loads such as snow, ice, wind, based on project conditions

Page 69: Thermal Expansion in Pipes

Intermediate AnchorsIntermediate anchors between expansion devices do not see the full load.

X

Intermediate Anchor

MainAnchor

X X

MainAnchor

Expansion Joint

EJMA recommends to design intermediate anchors for the spring load of one of the joints

Page 70: Thermal Expansion in Pipes

X

MainAnchor

X

X

Expansion Joint

Anchors at fittings can have multi-directional loads

Force

Force

Page 71: Thermal Expansion in Pipes

Expansion Joint

Location

Makes a Difference

Page 72: Thermal Expansion in Pipes

Guiding

Page 73: Thermal Expansion in Pipes

Column strength of pipe.

Page 74: Thermal Expansion in Pipes

Total Anchor Force

4495 Pressure Thrust614 Deflection Load719 Friction Resistance5,828.9 lbs force

Remember our Example

Page 75: Thermal Expansion in Pipes

LINERS•When velocity is high and could set up vibration in bellows

•Compressed air lines

•Exhaust gases

•Abrasive flow media

•Rule of Thumb :When velocity > 10 FPS

Page 76: Thermal Expansion in Pipes

Install 1st. Guide a max. of 4 pipe dia. From the expansion joint.Install 2nd. Guide a max. of 14 pipe dia. From the 1st. Guide. Additional guides as per EJMA recommendations

Page 77: Thermal Expansion in Pipes
Page 78: Thermal Expansion in Pipes

Bellows Pro/Con

Low/ no pressure drop High anchor loads

Externally pressurized-large movement

Easy to insulate

Custom fit

No maintenance

Very compact Engineered anchors

Considerable guiding requirements

Pro Con

Torque can be a problem

Page 79: Thermal Expansion in Pipes

Slip type Joints

Page 80: Thermal Expansion in Pipes

Slip Type Joint

Page 81: Thermal Expansion in Pipes

Slip Joint construction detail

Page 82: Thermal Expansion in Pipes

Ball Joints

Always in, at least pairs

Similar construction with Slip joints

Same maintenance issues

Page 83: Thermal Expansion in Pipes

Slip Type Pro/Con

Low/ no pressure drop High anchor loads

Custom fit

Large movementVery compact

Very expensive

Low or no cycling is a detriment.

Very High maintenance –packing frequently needed

Crucial and Considerable guiding requirements

Engineered anchors

Pro Con

Page 84: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

Lets Start With Determining The Pipe Size and Pipe Dimensions

Page 85: Thermal Expansion in Pipes

To Calculate Expansion

1 Determine design temperature – for example 200° F.

2 Establish installation temperature - For example 50° F

3 Find the expansion rate per 100 feet –1.179” / 100 feet for steel – 1.728” / 100 feet for copper

4 Determine the length of pipe run – for example 165 feet

5 Multiply the expansion rate by the length.(165 / 100) X 1.179 = 1.94” Expansion

6 If the joint is for both thermal and seismic, the values must be added together!

Page 86: Thermal Expansion in Pipes

For An Example

Lets use

Pipe Material Carbon SteelService Hot WaterDesign Temperature 200°FInstallation Temperature 50° FTemperature Difference ΔT 150°FExpansion Rate ΔL 1.179 inches / 100 Feet

Page 87: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

Lets Calculate How Much The Pipe Will Expand

Page 88: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

Lets Establish The Anchor Points

X

X X

X

XX

Anchor(typ)

Anchor(typ)

Page 89: Thermal Expansion in Pipes

First check for Natural

Flexibility

First check for Natural

Flexibility

Page 90: Thermal Expansion in Pipes

Keep in Mind

90° changes in direction are the most efficient piping configuration to use to take up thermal expansion or contraction.

Smaller angles will compound the movements!

Page 91: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

Next, Use Any Natural Flexibility Of The System

X

X X

X

XX

Anchor(typ)

Anchor(typ)

22’

13’

Page 92: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

Next, Complete The System WithFlexible Pipe Loops

X

X X

X

XX

Anchor(typ)

Anchor(typ)

22’

13’MLW81200

MLW80800

MLW30600

Page 93: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

X

X X

X

XX

Anchor(typ)

Anchor(typ)

22’

13’

Or, Complete The System WithExpansion Joints

Don’t forget about the guides. Note the placementof the Metragators

Page 94: Thermal Expansion in Pipes

12”8”

6”

250’ 75’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.88”

0.88”

What if the 75 foot run was only 18 feet?

X

X X

X

XX

Anchor(typ)

Anchor(typ)

22’

13’

Page 95: Thermal Expansion in Pipes

12”8”

6”

250’ 18’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.21”

0.88”

Option 1Use a Hose & Braid Dog Leg

X

X X

X

XX

Anchor(typ)

Anchor(typ)

40”

13’

Page 96: Thermal Expansion in Pipes

12”8”

6”

250’ 18’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.21”

0.88”

Option 2Add an Anchor, and another expansion device

X

X X

X

XX

Anchor(typ)

Anchor(typ)

18’

13’

X

Page 97: Thermal Expansion in Pipes

12”8”

6”

250’ 18’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.21”

0.88”

Next, Complete The System WithFlexible Pipe Loops

X

X X

X

XX

Anchor(typ)

Anchor(typ)

18’

13’MLW81200

MLW80800

MLW30600

X

MLW30800

Page 98: Thermal Expansion in Pipes

12”8”

6”

250’ 18’

85’ 75’

150’

150’

75’

2.95”

1.0”

1.77

”1.

77”

0.88

0.21”

0.88”

Or with Expansion Joints

X

X X

X

XX

Anchor(typ)

Anchor(typ)

22’

13’

X

Page 99: Thermal Expansion in Pipes