Products >  Metraloop®

Metraloop® expansion joints for thermal expansion applications

metraloop-flange-NEW3

hard-pipe-loop-illustation

Seismic, thermal and building movement expansion joint

Pipes transporting hot or chilled water, steam and chemicals are all subject to varying internal temperatures — as well as significant thermal expansion. While a flexible stainless steel hose and braid assembly is excellent for absorbing lateral offset and angular movement, it’s not designed for axial compression or torque. Under compression, the braid is relaxed and its pressure rating lowered, while torque introduces complex stresses that quickly fatigue the hose.

If flexible hose and braid are to be used as the stress-relieving, movement-compensating component of a piping system, it must be installed in a configuration that minimizes axial compression.

Figure 1, Figure 2That’s where the Metraloop joint comes in. Made of flexible stainless steel hose and braid, it accommodates lateral offset and angular movement. In a pipe run with axial expansion and contraction, a Metraloop installed in a hanging down configuration with its legs perpendicular to axial movement (Figure 1) can flex laterally. As long as the legs are designed with sufficient live length, the offset amount never exceeds the elastic limit of the hose, enabling it to flex indefinitely.

Compare that to the “L” shaped configuration of hose and braid (Figure 2). One leg of the assembly is always subjected to axial force (except in a chilled water application, where the pipe is contracting). In addition to being less reliable, the “L” shaped configuration has an offset pipe that costs more and is more difficult to fit than Metraloop.

Compared to conventional bellows-type expansion joints and hard pipe loops, Metraloop exerts a fraction of the anchor load, requires far fewer pipe guides, and takes less space – all significantly reducing overall project costs.

There’s no limit to the thermal applications that Metraloop can handle. It can even be designed with lined hose for high velocity, double-braid for high pressures, and all stainless steel construction for media compatibility.

SWEAT ENDS

Copper sweat ends with bronze hose & braid
(† See Temp Correction Factor)
Custom movements available. Contact Factory.

PIPE
SIZE
MODEL # MOVEMENT END TO
END
LENGTH PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
*SPRING
FORCE
LBS.
WEIGHT
LBS.
3D DRAWING
1/2″       (15mm) MLS30050 ±1.5″ 7-3/4″ 11-1/2″ 706 1130 45 2 Revit/CAD
MLS80050 ±4″ 7-/34″ 15-3/8″ 2.5 Revit/CAD
3/4″       (20mm) MLS30075 ±1.5″ 9-1/2″ 13-1/8″ 577 923 47 2 Revit/CAD
MLS80075 ±4″ 9-1/2″ 17-1/4″ 2.5 Revit/CAD
1″          (25mm) MLS30100 ±1.5″ 10-1/4″ 14-5/8″ 470 752 53 2.5 Revit/CAD
MLS80100 ±4″ 10-1/4″ 19-1/4″ 3 Revit/CAD
1-1/4″     (30mm) MLS30125 ±1.5″ 11-1/8″ 16-3/8″ 361 577 66 3.5 Revit/CAD
MLS80125 ±4″ 11-1/8″ 21-3/8″ 4 Revit/CAD
1-1/2″     (40mm) MLS30150 ±1.5″ 11-5/8″ 17-1/4″ 329 526 70 4 Revit/CAD
MLS80150 ±4″ 11-5/8″ 22-1/2″ 4.5 Revit/CAD
2″          (50mm) MLS30200 ±1.5″ 13-3/8″ 18-3/4″ 317 507 78 9 Revit/CAD
MLS80200 ±4″ 13-3/8″ 24-3/4″ 12 Revit/CAD
2-1/2″     (65mm) MLS30250 ±1.5″ 15″ 19-3/4″ 272 435 83 12 Revit/CAD
MLS80250 ±4″ 17″ 26-1/2″ 18 Revit/CAD
3″          (80mm) MLS30300 ±1.5″ 16″ 21-1/2″ 201 322 90 18 Revit/CAD
MLS80300 ±4″ 18-1/2″ 28-1/2″ 24 Revit/CAD
4″        (100mm) MLS30400 ±1.5″ 20″ 24-3/4″ 142 227 120 26 Revit/CAD
MLS80400 ±4″ 22″ 32″ 31 Revit/CAD

† When ordering a Metraloop with double-braid, please include the letter “D” at the end of the Model #. Example: MLW30200D
* Spring Force: These values reflect the total force required to move the Metraloop its full rated movement for 150 P.S.I. at 70 F.
For higher pressures please contact Metraflex.
** Loops are available in half sections for ease of handling and shipping. If this option is selected add half inch to the “end to end” dimension.

THREAD ENDS

Fittings – Sched. 40 Carbon Steel Hose & Braid – Series 300 Stainless Steel
(† See Temp Correction Factor)
Custom movements available. Contact Factory.

PIPE
SIZE
MODEL # MOVEMENT END TO
END
LENGTH PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
3D DRAWING
1/2″       (15mm) MLT30050 ±1.5″ 12″ 10-1/4″ 1075 1720 300 45 3 Revit/CAD
MLT80050 ±4″ 15″ 15-5/8″ 5.5 Revit/CAD
3/4″       (20mm) MLT30075 ±1.5″ 12-1/4″ 10-3/4″ 792 1267 300 47 3 Revit/CAD
MLT80075 ±4″ 15-1/4″ 17-1/2″ 5.5 Revit/CAD
1″          (25mm) MLT30100 ±1.5″ 12″ 12″ 571 914 300 53 5 Revit/CAD
MLT80100 ±4″ 16″ 18-5/8″ 8 Revit/CAD
1-1/4″     (30mm) MLT30125 ±1.5″ 13-1/2″ 13-3/8″ 531 850 300 66 7 Revit/CAD
MLT80125 ±4″ 16-3/4″ 20″ 10 Revit/CAD
1-1/2″     (40mm) MLT30150 ±1.5″ 15″ 14-3/4″ 472 755 300 70 10.5 Revit/CAD
MLT80150 ±4″ 17-1/2″ 21-1/4″ 14.5 Revit/CAD
2″          (50mm) MLT30200 ±1.5″ 18″ 17-3/8″ 500 750 300 78 15 Revit/CAD
MLT80200 ±4″ 20″ 24/1/2″ 18 Revit/CAD
2-1/2″     (65mm) MLT30250 ±1.5″ 21″ 21″ 387 619 300 83 23 Revit/CAD
MLT80250 ±4″ 21-1/2″ 28-1/4″ 29 Revit/CAD
3″          (80mm) MLT30300 ±1.5″ 26″ 23-3/8″ 288 431 216 90 39 Revit/CAD
MLT80300 ±4″ 26″ 30″ 43 Revit/CAD
4″        (100mm) MLT30400 ±1.5″ 32″ 28″ 232 371 186 120 55 Revit/CAD
MLT80400 ±4″ 32″ 35-3/8″ 59 Revit/CAD

† When ordering a Metraloop with double-braid, please include the letter “D” at the end of the Model #. Example: MLW30200D
* Spring Force: These values reflect the total force required to move the Metraloop its full rated movement for 150 P.S.I. at 70 F.
For higher pressures please contact Metraflex.
** Loops are available in half sections for ease of handling and shipping. If this option is selected add half inch to the “end to end” dimension.

150# FLANGED ENDS

Fittings – Sched. 40 Carbon/Steel Hose & Braid – Series 300 Stainless Steel
(† See Temp Correction Factor)
Custom movements available. Contact Factory.

PIPE
SIZE
MODEL # MOVEMENT END TO
END
LENGTH PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
3D DRAWING
2″          (50mm) MLF30200 ±1.5″ 12-1/2″ 17-3/8″ 500 750 300 78 21 Revit/CAD
MLF80200 ±4″ 14-1/2″ 24-1/2″ 24 Revit/CAD
2-1/2″     (65mm) MLF30250 ±1.5″ 15-1/2″ 21″ 387 619 300 83 30 Revit/CAD
MLF80250 ±4″ 16″ 28-1/4″ 36 Revit/CAD
3″          (80mm) MLF30300 ±1.5″ 18-1/2″ 23-3/8″ 288 431 216 90 46 Revit/CAD
MLF80300 ±4″ 18-1/2″ 30″ 50 Revit/CAD
4″        (100mm) MLF30400 ±1.5″ 24-1/2″ 28″ 232 371 183 120 63 Revit/CAD
MLF80400 ±4″ 24-1/2″ 35-3/8″ 69 Revit/CAD
5″        (125mm) MLF30500 ±1.5″ 30-1/2″ 32-1/4″ 191 306 153 186 91 Revit/CAD
MLF80500 ±4″ 30-1/2″ 40-1/4″ 101 Revit/CAD
6″        (150mm) MLF30600 ±1.5″ 36-1/2″ 36-3/4″ 165 264 132 202 148 Revit/CAD
MLF80600 ±4″ 36-1/2″ 45-3/8″ 163 Revit/CAD
8″        (200mm) MLF30800 ±1.5″ 48-1/2″ 44-1/2″ 212 230 115 260 287 Revit/CAD
MLF80800 ±4″ 48-1/2″ 53-1/2″ 309 Revit/CAD
10″       (250mm) MLF31000 ±1.5″ 60-1/2″ 53-1/4″ 175 200 100 283 453 Revit/CAD
MLF81000 ±4″ 60-1/2″ 63-1/4″ 484 Revit/CAD
12″       (300mm) MLF31200 ±1.5″ 72-1/2″ 61-3/4″ 160 188 94 390 636 Revit/CAD
MLF81200 ±4″ 72-1/2″ 72-3/4″ 666 Revit/CAD
14″       (355mm) MLF31400 ±1.5″ 84-1/2″ 71″ 110 125 63 706 636 Revit/CAD
MLF81400 ±4″ 84-1/2″ 80.5″ 666 Revit/CAD
16″ **     (400mm) MLF31600 ±1.5″ 96-1/2″ 78.5″ 110 170 85 900 636 Revit/CAD
MLF81600 ±4″ 96-1/2″ 91.5″ 666 Revit/CAD
18″ **     (455mm) MLF31800 ±1.5″ 108-1/2″ 86.5″ 85 150 75 1000 636 Revit/CAD
MLF81800 ±4″ 108-1/2″ 100″ 666 Revit/CAD

† When ordering a Metraloop with double-braid, please include the letter “D” at the end of the Model #. Example: MLW30200D
* Spring Force: These values reflect the total force required to move the Metraloop its full rated movement for 150 P.S.I. at 70 F.
For higher pressures please contact Metraflex.
** Loops are available in half sections for ease of handling and shipping. If this option is selected add half inch to the “end to end” dimension.

WELD ENDS

Fittings – Sched. 40 Carbon/Steel Hose & Braid – Series 300 Stainless Steel
(† See Temp Correction Factor)
Custom movements available. Contact Factory.

PIPE
SIZE
MODEL # MOVEMENT END TO
END
LENGTH PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
3D DRAWING
1/2″       (15mm) MLW30050 ±1.5″ 6″ 10-1/4″ 1075 1720 300 45 2.5 Revit/CAD
MLW80050 ±4″ 9″ 15-5/8″ 5 Revit/CAD
3/4″       (20mm) MLW30075 ±1.5″ 5-1/4″ 10-3/4″ 792 1267 300 47 2.5 Revit/CAD
MLW80075 ±4″ 9-1/4″ 17-1/2″ 5 Revit/CAD
1″          (25mm) MLW30100 ±1.5″ 6″ 12″ 571 914 300 53 4 Revit/CAD
MLW80100 ±4″ 10″ 18-5/8″ 7 Revit/CAD
1-1/4″     (30mm) MLW30125 ±1.5″ 7-1/2″ 13-3/8″ 531 850 300 66 6 Revit/CAD
MLW80125 ±4″ 10-3/4″ 20″ 9 Revit/CAD
1-1/2″     (40mm) MLW30150 ±1.5″ 9″ 14-3/4″ 472 755 300 70 9 Revit/CAD
MLW80150 ±4″ 11-1/2″ 21-1/4″ 13 Revit/CAD
2″          (50mm) MLW30200 ±1.5″ 12″ 17-3/8″ 500 750 300 78 13 Revit/CAD
MLW80200 ±4″ 14″ 24-1/2″ 16 Revit/CAD
2-1/2″     (65mm) MLW30250 ±1.5″ 15″ 21″ 387 619 300 83 20 Revit/CAD
MLW80250 ±4″ 15-1/2″ 28-1/4″ 26 Revit/CAD
3″          (80mm) MLW30300 ±1.5″ 18″ 23-3/8″ 288 431 216 90 35 Revit/CAD
MLW80300 ±4″ 18″ 30″ 39 Revit/CAD
4″        (100mm) MLW30400 ±1.5″ 24″ 28″ 232 371 186 120 48 Revit/CAD
MLW80400 ±4″ 24″ 35-3/8″ 54 Revit/CAD
5″        (125mm) MLW30500 ±1.5″ 30″ 32-1/4″ 191 306 153 186 81 Revit/CAD
MLW80500 ±4″ 30″ 40-1/4″ 91 Revit/CAD
6″        (150mm) MLW30600 ±1.5″ 36″ 36-3/4″ 165 264 132 202 125 Revit/CAD
MLW80600 ±4″ 36″ 45-3/8″ 140 Revit/CAD
8″        (200mm) MLW30800 ±1.5″ 48″ 44-1/2″ 212 230 115 260 245 Revit/CAD
MLW80800 ±4″ 48″ 53-1/2″ 267 Revit/CAD
10″       (250mm) MLW31000 ±1.5″ 60″ 53-1/4″ 175 200 100 383 403 Revit/CAD
MLW81000 ±4″ 60″ 63-1/4″ 434 Revit/CAD
12″       (300mm) MLW31200 ±1.5″ 72″ 61-3/4″ 160 188 94 390 556 Revit/CAD
MLW81200 ±4″ 72″ 72-3/4″ 586 Revit/CAD

† When ordering a Metraloop with double-braid, please include the letter “D” at the end of the Model #. Example: MLW30200D
* Spring Force: These values reflect the total force required to move the Metraloop its full rated movement for 150 P.S.I. at 70 F.
For higher pressures please contact Metraflex.
** Loops are available in half sections for ease of handling and shipping. If this option is selected add half inch to the “end to end” dimension.

GROOVED ENDS

Fittings – Sched. 40 Carbon/Steel Hose & Braid – Series 300 Stainless Steel
(† See Temp Correction Factor)
Custom movements available. Contact Factory.

PIPE
SIZE
MODEL # MOVEMENT FACE TO
FACE
LENGTH PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
*SPRING
FORCE
LBS.
WEIGHT
LBS.
3D DRAWING
2″          (50mm) MLG30200 ±1.5″ 18″ 17-3/8″ 500 750 78 15 Revit/CAD
MLG80200 ±4″ 20″ 24-1/2″ 18 Revit/CAD
2-1/2″     (65mm) MLG30250 ±1.5″ 21″ 21″ 387 619 83 23 Revit/CAD
MLG80250 ±4″ 21-1/2″ 28-1/4″ 29 Revit/CAD
3″          (80mm) MLG30300 ±1.5″ 24″ 23-3/8″ 288 431 90 39 Revit/CAD
MLG80300 ±4″ 24″ 30″ 43 Revit/CAD
4″        (100mm) MLG30400 ±1.5″ 30″ 28″ 232 371 120 54 Revit/CAD
MLG80400 ±4″ 30″ 35-3/8″ 60 Revit/CAD
5″        (125mm) MLG30500 ±1.5″ 36″ 32-1/4″ 191 306 186 89 Revit/CAD
MLG80500 ±4″ 36″ 40-1/4″ 99 Revit/CAD
6″        (150mm) MLG30600 ±1.5″ 42″ 36-3/4″ 165 264 202 135 Revit/CAD
MLG80600 ±4″ 42″ 45-3/8″ 150 Revit/CAD
8″        (200mm) MLG30800 ±1.5″ 56″ 44-1/2″ 212 230 260 264 Revit/CAD
MLG80800 ±4″ 56″ 53-1/2″ 286 Revit/CAD
10″       (250mm) MLG31000 ±1.5″ 68″ 53-1/4″ 175 200 283 430 Revit/CAD
MLG81000 ±4″ 68″ 63-1/4″ 461 Revit/CAD
12″       (300mm) MLG31200 ±1.5″ 80″ 61-3/4″ 160 188 390 592 Revit/CAD
MLG81200 ±4″ 80″ 72-3/4″ 622 Revit/CAD

† When ordering a Metraloop with double-braid, please include the letter “D” at the end of the Model #. Example: MLW30200D
* Spring Force: These values reflect the total force required to move the Metraloop its full rated movement for 150 P.S.I. at 70 F.
For higher pressures please contact Metraflex.
** Loops are available in half sections for ease of handling and shipping. If this option is selected add half inch to the “end to end” dimension.

TEMPERATURE CORRECTION FACTORS
For safe working pressures above 70°F multiply the pressures shown at 70°F by the correction factor for the required temperature.

TEMPERATURE °F CORRECTION FACTOR
BRONZE STAINLESS STEEL
70 ° 1.0 1.0
200 ° .89 .92
300 ° .83 .86
400 ° .78 .82
500 ° .77
600 ° .73

Metraloop Options
The sizes, pressures and movements shown reflect our standard Metraloops. Higher pressure, greater movements and special materials, such as all stainless steel construction are available. Please contact your local Metraflex representative or the factory for more information.

Metraflex reserves the right to change product specifications, designs and standard equipment without notice and without incurring obligation.

Refer to the following for installation configurations.

Pressure Drop (Friction Loss) Charts
Use the charts below for all styles (except copper) of Metraloop expansion loops and Fireloops and all end fittings. Please contact factory for copper expansion loop (MLS) pressure loss information.

Download a .PDF version of these charts.

1/2" PIPE

(calculated for water at 60 deg. F.)

drop_050

3/4" PIPE

(calculated for water at 60 deg. F.)

drop_075

1" PIPE

(calculated for water at 60 deg. F.)

drop_100

1-1/4" PIPE

(calculated for water at 60 deg. F.)

drop_125

1-1/2" PIPE

(calculated for water at 60 deg. F.)

drop_150

2" PIPE

(calculated for water at 60 deg. F.)

drop_200

2-1/2" PIPE

(calculated for water at 60 deg. F.)

drop_250

3" PIPE

(calculated for water at 60 deg. F.)

drop_300

4" PIPE

(calculated for water at 60 deg. F.)

drop_150

5" PIPE

(calculated for water at 60 deg. F.)

drop_500

6" PIPE

(calculated for water at 60 deg. F.)

drop_600

8" PIPE

(calculated for water at 60 deg. F.)

drop_800

Configurations

Metraloop hanging down - Horizontal run

Metraloop

Loop should hang straight down and be free to flex. Guides are required to direct movement axially.

Download CAD Drawing

Metraloop straight up - Horizontal run

Metraloop

Support must be provided to prevent the loop from leaning. Pipe hanger rod should be loose enough to allow the 180ƒ return to move up or down 1/4″ as the loop flexes. Guides are required to direct movement of pipe axially.

Download CAD Drawing

Metraloop horizontal - Horizontal run

Metraloop

This installation is recommended for steam*. Support must be provided to prevent the loop from drooping or torquing pipe. Support must allow the 180ƒ return, to move horizontally back and forth 1/4″, as the loop flexes. Guides are required to direct movement of pipe axially.

*Any other orientation may cause condensate to collect.

Download CAD Drawing

Metraloop - Vertical Run

Metraloop

Loop must be supported to allow the 180ƒ return to move horizontally back and forth 1/4″ as the loop flexes. Guides are required to direct movement of pipe axially.

Download CAD Drawing

Metraloop - Nested

Metraloop

For tight pipe runs, any size or number of loops can be designed to nest inside of one another. To order, specify sequence of pipe diameters and corresponding distances between pipe centerlines.

Download CAD Drawing

Metraloop - Inside corner

Metraloop

One Metraloop simultaneously absorbs the thermal expansion of two pipe runs. Space-saving inside corner Metraloop eliminates the need for an anchor at the corner. Guides are required to direct movement of pipe axially. Support must be provided to prevent Metraloop from drooping or torquing pipe and must allow for sufficient movement.

Download CAD Drawing

Metraloop over-under

Metraloop

The Metraloop expansion loop can be manufactured in a variety of configurations. For technical assistance, contact your nearest Metraflex representative, or contact Metraflex directly.

Download CAD Drawing

Metraloop over-over

Metraloop

The Metraloop expansion loop can be manufactured in a variety of configurations. For technical assistance, contact your nearest Metraflex representative, or contact Metraflex directly.

Download CAD Drawing

Metraloop with Flanged Ends

Metraloop

Simple, two-dimensional CAD drawing you can download and import into your piping system design. The Metraloop can be installed hanging down, straight up and horizontally when properly guided. Support must be provided for installations other than hanging straight down to prevent the loop from leaning, drooping or torquing.

Download CAD Drawing

Metraloop Comparison