Product Made in Japan
Manufacturer: NFK
Model: NK-7300, NK-7300E

NFK expansion joints are used in gas and liquid transport system lines used by steel making, chemical and industrial plants to transport substances such as air, water, gases, steam, oil and exhaust gases. They can compensate for expansion and contraction caused by temperature differences in air-conditioning/sanitation lines in buildings and other structures. They also handle conditions such as line center misalignment, vibrations, foundation subsidence and earthquakes.

Feature

This product is non welding. Production of short face-to-face can be a structure in which to flare the flange end face the bellows.
Applicable fluid: Exhaust gas Air Low pressure steam Water
Applicable bellows: iO, E
Material: SUS304 SUS316L SUS310S
*Please contact us for material.
Standard：JIS, ANSI, DIN

 

Specification

 

Drawing

 

NK-7300

 

 

Materials

 

① Bellows	Stainless Steel
② Inner Sleeve	Stainless Steel
③ Flange	Carbon steel, Stainless Steel
④ Shipping Bolt	Carbon steel, Stainless Steel
⑤ Holder	Carbon steel, Stainless Steel

Bellows for NK-7300E E Bellows

 

Nominal diameter	Thickness(mm)	ID(mm)	Convolution Height(mm)	Pitch(mm)	Expansion / contraction amount per Convolution(mm)	Spring Rate(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

Bellows for NK-7300 iO Bellows

 

DN	Bellows Size(mm)				Production possible Convolution	Spring Rate(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