Metraloop expansion joints for thermal expansion applications
For gas, steam, water, chemical pipe lines
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.
That'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.
† 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.
† 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.
† 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.
† 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.
† 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.
Copper sweat ends with bronze hose & braid
(† See Temp Correction Factor)
PIPE SIZE
MODEL #
MOVEMENT
END TO END
LENGTH
PSI SINGLE BRAID
†PSI DOUBLE BRAID
*SPRING FORCE LBS.
WEIGHT LBS.
1/2" (15mm)
MLSNSF80050
±4"
7-3/4"
12-3/4"
706
1130
45
2.5
3/4" (20mm)
MLSNSF80075
±4"
9-1/2"
16-1/2"
577
923
47
2.5
1" (25mm)
MLSNSF80100
±4"
10-1/4"
18-7/8"
470
752
53
3
1-1/4" (30mm)
MLSNSF80125
±4"
11-1/8"
20-3/8"
361
577
66
4
1-1/2" (40mm)
MLSNSF80150
±4"
11-5/8"
22-1/2"
329
526
70
4.5
2" (50mm)
MLSNSF80200
±4"
13-3/8"
24-1/2"
317
507
78
12
2-1/2" (65mm)
MLSNSF80250
±4"
15"
27"
272
435
83
18
3" (80mm)
MLSNSF80300
±4"
16-1/2"
29"
201
322
90
24
4" (100mm)
MLSNSF80400
±4"
22"
32"
142
227
120
31
† When ordering a Metraloop with double-braid, please include the letter "D" at the end of the Model #. Example: MLWNSF30200D
* 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.
Fittings - Sched. 40 Carbon Steel Hose & Braid - Series 300 Stainless Steel
(† See Temp Correction Factor)
PIPE
SIZE
MODEL #
MOVEMENT
END TO
END
LENGTH
PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
1/2" (15mm)
MLTNSF80050
±4"
15"
15-1/4"
1075
1720
300
45
5.5
3/4" (20mm)
MLTNSF80075
±4"
15-1/4"
16-1/8"
792
1267
300
47
5.5
1" (25mm)
MLTNSF80100
±4"
16"
17-3/4"
571
914
300
53
8
1-1/4" (30mm)
MLTNSF80125
±4"
16-3/4"
19-1/8"
531
850
300
66
10
1-1/2" (40mm)
MLTNSF80150
±4"
17-1/2"
21-1/2"
472
755
300
70
14.5
2" (50mm)
MLTNSF80200
±4"
20"
23-1/2"
500
750
300
78
18
2-1/2" (65mm)
MLTNSF80250
±4"
21"
27-1/4"
387
619
300
83
29
3" (80mm)
MLTNSF80300
±4"
24"
30"
288
431
216
90
43
4" (100mm)
MLTNSF80400
±4"
30"
35"
232
371
186
120
59
† When ordering a Metraloop with double-braid, please include the letter "D" at the end of the Model #. Example: MLWNSF30200D
* 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.
Fittings - Sched. 40 Carbon/Steel Hose & Braid - Series 300 Stainless Steel
(† See Temp Correction Factor)
PIPE
SIZE
MODEL #
MOVEMENT
END TO
END
LENGTH
PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
2" (50mm)
MLFNSF80200
±4"
14-1/2"
23-1/2"
500
750
300
78
24
2-1/2" (65mm)
MLFNSF80250
±4"
17-1/2"
27-1/4"
387
619
300
83
36
3" (80mm)
MLFNSF80300
±4"
18-1/2"
30"
288
431
216
90
50
4" (100mm)
MLFNSF80400
±4"
24-1/2"
35"
232
371
183
120
69
5" (125mm)
MLFNSF80500
±4"
30-1/2"
40"
191
306
153
186
101
6" (150mm)
MLFNSF80600
±4"
36-1/2"
46"
165
264
132
202
163
8" (200mm)
MLFNSF80800
±4"
48-1/2"
58"
212
230
115
260
309
10" (250mm)
MLFNSF81000
±4"
60-1/2"
67"
175
200
100
283
484
12" (300mm)
MLFNSF81200
±4"
72-1/4"
74"
160
188
94
390
666
† When ordering a Metraloop with double-braid, please include the letter "D" at the end of the Model #. Example: MLWNSF30200D
* 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.
Fittings - Sched. 40 Carbon/Steel Hose & Braid - Series 300 Stainless Steel
(† See Temp Correction Factor)
PIPE
SIZE
MODEL #
MOVEMENT
END TO
END
LENGTH
PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
MAX
SATURATED
STEAM
PRESS.
*SPRING
FORCE
LBS.
WEIGHT
LBS.
1/2" (15mm)
MLWNSF80050
±4"
9"
15-1/4"
1075
1720
300
45
5
3/4" (20mm)
MLWNSF80075
±4"
9-1/4"
16-1/8"
792
1267
300
47
5
1" (25mm)
MLWNSF80100
±4"
10"
17-3/4"
571
914
300
53
7
1-1/4" (30mm)
MLWNSF80125
±4"
10-3/4"
19-1/8"
531
850
300
66
9
1-1/2" (40mm)
MLWNSF80150
±4"
11-1/2"
21-1/2"
472
755
300
70
13
2" (50mm)
MLWNSF80200
±4"
14"
23-1/2"
500
750
300
78
16
2-1/2" (65mm)
MLWNSF80250
±4"
17"
27-1/4"
387
619
300
83
26
3" (80mm)
MLWNSF80300
±4"
18"
30"
288
431
216
90
39
4" (100mm)
MLWNSF80400
±4"
24"
35"
232
371
186
120
54
5" (125mm)
MLWNSF80500
±4"
30"
40"
191
306
153
186
91
6" (150mm)
MLWNSF80600
±4"
36"
46"
165
264
132
202
140
8" (200mm)
MLWNSF80800
±4"
48"
58"
212
230
115
260
267
10" (250mm)
MLWNSF81000
±4"
60"
67"
175
200
100
383
434
12" (300mm)
MLWNSF81200
±4"
72"
74"
160
188
94
390
586
† When ordering a Metraloop with double-braid, please include the letter "D" at the end of the Model #. Example: MLWNSF30200D
* 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.
Fittings - Sched. 40 Carbon/Steel Hose & Braid - Series 300 Stainless Steel
(† See Temp Correction Factor)
PIPE
SIZE
MODEL #
MOVEMENT
FACE TO
FACE
LENGTH
PSI
SINGLE
BRAID
†PSI
DOUBLE
BRAID
*SPRING
FORCE
LBS.
WEIGHT
LBS.
2" (50mm)
MLGNSF80200
±4"
20"
23-1/2"
500
750
78
18
2-1/2" (65mm)
MLGNSF80250
±4"
23"
27-1/4"
387
619
83
29
3" (80mm)
MLGNSF80300
±4"
24"
30"
288
431
90
43
4" (100mm)
MLGNSF80400
±4"
30"
35"
232
371
120
60
5" (125mm)
MLGNSF80500
±4"
36"
40"
191
306
186
99
6" (150mm)
MLGNSF80600
±4"
42"
46"
165
264
202
150
8" (200mm)
MLGNSF80800
±4"
56"
58"
212
230
260
286
10" (250mm)
MLGNSF81000
±4"
68"
67"
175
200
283
461
12" (300mm)
MLGNSF81200
±4"
80"
74"
160
188
390
622
† When ordering a Metraloop with double-braid, please include the letter "D" at the end of the Model #. Example: MLWNSF30200D
* 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.
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 pages for installation configurations and technical assistance.
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.
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.
The Metraflex Company, 2323 W. Hubbard Street, Chicago, IL 60612 | 800-621-4347 | 312-738-3800 | Fax 312-738-0415 |