Expansion Joints

NK-7900・NK-7900E

Compact and Light type

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Feature

This product welds inside of flange to a bellows. Light & Compact.
Applicable bellows: Exhaust gas, Special gas, Air, water
Applicable bellows: iO, E
Material: SUS304 SUS316L SUS310S
*Please contact us for material.
Standard: JIS, ANSI, DIN

NK-7900

Materials

Bellows Stainless Steel
Flange Carbon steel, Stainless Steel

*You can add Internal Sleeve and Shipping Bolt as options if you need.

View Steel Types

Bellows for NK-7900 iO Bellows

DN Bellows Size(mm) Production possible Convolution Resisting
pressure(N/mm)		 Expansion / contraction amount per Convolution(mm) Effective cross section(㎟)
Thickness Convolution Height Pitch ID
20 0.3 4.7 6.0 27.0 32 1352.8 0.45 819.4
25 0.3 5.5 6.3 33.5 32 1092.6 0.55 1228.5
32 0.3 6.7 7.0 42.0 32 787.9 0.75 1908.9
40 0.35 6.9 7.5 47.5 32 1255.1 0.75 2384.5
50 0.35 7.4 8.5 59.5 32 1214.4 0.90 3589.1
65 0.4 9.6 9.5 75.0 25 1130.0 1.20 5728.0
80 0.4 10.6 10.5 88.0 25 976.6 1.40 7760.0
100 0.4 10.6 10.5 113.0 25 888.5 1.60 12449.2
125 0.5 11.0 12.0 138.0 38 4941.2 1.40 17671.5
150 0.5 13.0 15.0 164.0 30 3450.5 1.80 24884.6
200 0.5 13.0 15.0 216.0 30 2216.8 1.80 41547.6
250 0.5 16.0 18.0 268.0 25 1492.2 2.70 63794.0
300 0.5 18.0 20.0 317.0 22 1243.2 3.50 88668.3
350 0.6 18.0 20.0 356.0 22 2398.9 3.00 110564.5
400 0.6 23.0 25.0 406.0 17 1333.0 4.70 145355.2
450 0.6 23.0 25.0 456.0 17 2983.2 4.70 181106.6
500 0.6 23.0 25.0 507.0 14 1645.9 5.90 225978.7
550 0.8 32.0 35.0 558.0 12 1803.9 7.80 270992.8
600 0.8 32.0 35.0 609.0 12 1747.0 7.80 320092.6
650 0.8 32.0 35.0 660.0 12 1885.6 7.80 377622.2
700 0.8 32.0 35.0 710.0 12 2021.6 7.00 434278.8
750 0.8 32.0 35.0 762.0 12 2162.9 7.00 497140.8
800 0.8 36.0 40.0 812.0 9 1609.5 8.70 566916.2
850 0.8 36.0 40.0 864.0 9 1708.0 8.70 638436.5
900 0.8 36.0 40.0 914.0 9 1802.7 8.70 711211.5
1000 0.8 40.0 45.0 1015.0 8 1450.2 10.50 876821.3
1100 0.8 40.0 45.0 1117.6 8 1590.9 10.50 1055374.6
1200 0.8 40.0 45.0 1219.2 8 1730.4 10.50 1248482.0
1350 0.8 40.0 45.0 1371.6 8 1939.6 10.50 1568545.6
1500 0.8 40.0 45.0 1524.0 8 2148.7 10.50 1925092.1

Bellows for NK-7900E E Bellows

DN Thickness(mm) ID(mm) Convolution Height(mm) Pitch(mm) Expansion / contraction amount per Convolution(mm) Resisting
pressure(N/mm)
20 0.2 28.6 4.7 4.0 0.60 373.3
25 0.2 35.6 5.5 4.0 0.75 310.3
32 0.2 44.1 6.7 5.0 1.10 209.1
40 0.2 50.1 6.9 5.0 1.15 217.8
50 0.2 62.1 7.4 5.0 1.25 222.6
65 0.2 78.4 9.0 6.5 1.85 150.3
80 0.3 90.9 10.0 6.5 1.55 450.4
100 0.3 116.2 10.0 7.5 1.65 524.3
125 0.3 141.9 10.0 7.5 1.65 630.6
150 0.3 167.4 11.0 7.5 1.90 583.3
200 0.3 218.7 11.0 7.5 1.90 750.5
250 0.3 270.4 13.0 10.0 2.70 527.8
300 0.3 319.9 13.0 10.0 2.70 619.8
350 0.4 356.0 15.0 13.0 2.70 1268.0

The drawing can be downloaded from the link below.

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