Type	State	Code
Bright Surface	No coating on the inner and outer surface of steel pipe	SL
Copper plated surface	Copper plating on the outer surface of steel tube	Cu
Galvanized surface	Galvanized or zinc alloy on the outer surface of steel pipe	Zn
Double-sided copper plating surface	The inner and outer surfaces of the steel pipe are plated with copper	Cu/Cu
External galvanized inner copper plating surface	Galvanized or zinc alloy on the outer surface of steel pipe, copper plating on the inner surface	Zn/Cu
Use electroplating, electroless or hot dip plating. Manufacture of steel strip with double-sided copper plating, and the quality of the coating at the weld line should be negotiated by both suppliers and suppliers. Manufacture of steel strip with double-sided copper plating.

Table 2 Outer diameter, wall thickness and theoretical weight

OD/mm	WT/mm
	0.30	0.40	0.50	0.60	0.65	0.70	0.80	0.90	1.00	1.30
	theoretical weight /(kg/m)
3.18	0.0213	0.0274	0.0330
4.00	0.0274	0.0355	0.0432	0.0503
4.76	0.0330	0.0430	0.0525	0.0616	0.0659	0.0701
5.00	0.0348	0.0454	0.0555	0.0651	0.0697	0.0742
6.00	0.0422	0.0552	0.0678	0.0799	0.0858	0.0915	0.1026	0.1132	0.1233
6.35	0.0448	0.0587	0.0721	0.0851	0.0914	0.0975	0.1095	0.1210	0.1319
7.94	0.0565	0.0744	0.0917	0.1086	0.1169	0.1250	0.1409	0.1563	0.1712	0.2129
8.00	0.0570	0.0750	0.0925	0.1095	0.1178	0.1260	0.1421	0.1576	0.1726	0.2148
9.53	0.0683	0.0901	0.1113	0.1321	0.1423	0.1524	0.1722	0.1915	0.2104	0.2639
10.00	0.0718	0.0947	0.1171	0.1391	0.1499	0.1605	0.1815	0.2020	0.2220	0.2789
12.00	0.0866	0.1144	0.1418	0.1687	0.1819	0.1951	0.2210	0.2464	0.2713	0.3430
12.70	0.0917	0.1213	0.1504	0.1790	0.1932	0.2072	0.2348	0.2619	0.2885	0.3655
14.00	0.1014	0.1342	0.1665	0.1983	0.2140	0.2296	0.2604	0.2908	0.3206	0.4072
15.88	0.1153	0.1527	0.1896	0.2261	0.2441	0.2621	0.2975	0.3325	0.3670	0.4674
16.00	0.1162	0.1539	0.1911	0.2279	0.2461	0.2641	0.3000	0.3352	0.3699	0.4713
18.00	0.1310	0.1736	0.2158	0.2575	0.2781	0.2987	0.3393	0.3795	0.4192	0.5354
Theoretical weight of no additional coating, density of steel is 7.85 kg/

Table3 Allowable deviation of outer diameter of steel pipe

Table4 Permissible deviation of steel tube wall thickness

Table5 Allowable deviation of specified length of steel pipe

TABLE 6 Chemical Composition Of Steel Strip (Mass Fraction)%

Category	C	Si	Mn	P	S
Cold rolled low carbon steel strip	≤0.08	≤0.03	≤0.30	≤0.030	≤0.030
Cold rolled ultra low carbon steel strip	≤0.008	≤0.03	≤0.25	≤0.020	≤0.030

TABLE 7 Mechanical Properties Of Cold Rolled Low Carbon Steel Strip

Thickness /mm	Tensile Strength	Yield Strength	Elongation A/%
0.25~＜0.35	≥270		≥32
0.35~＜0.50			≥34
≥0.50			≥36
a Replace with when the yield phenomenon is not obvious. b Sample type of sample number D14 in GB/T 228-2002.

TABLE 8 Mechanical Properties Of Cold Rolled Ultra-low Carbon Steel Strip

Thickness /mm	Tensile Strength	Yield Strength	Elongation A/%
≤0.50	≥280	130~250	≥38
＞0.50	≥280	130~250	≥40
a Replace with when the yield phenomenon is not obvious. b Sample type of sample number P14 in GB/T 228-2002.

TABLE 9 Mechanical properties of steel pipe

Category	Tensile Strength	Yield Strength	Elongation A/%
Ordinary steel pipe(MA)	≥270	≥180	≥14
Soft steel tube(MB)	≥230	150~220	≥35
a Replace with when the yield phenomenon is not obvious. b Sample type of sample number S7 in GB/T 228-2002.

TABLE 10 Inspection Items, Test Methods And Sampling Quantity

NO	Inspection Items	Sampling Method ,Test Methods	Sampling Quantity
1	Chemical composition	GB/T 223, GB/T 4336, GB/T 20066 GB/T 20123, GB/T 20126	Take 1 samples per furnace
2	Mechanical property	GB/T 228	Take 1 samples per batch
3	Flattening test	GB/T 246	Take 1 samples per furnace
4	Expansion test	GB/T 242	Take 1 samples of two steel pipes per batch
5	Bending test	GB/T 244	Take 1 samples per batch
6	Hydraulic test	GB/T 241	Take 1 samples per batch
7	Flared test	Appendix A	Take 1 samples per batch
8	Requirements for the inner surface of high definition clean steel pipe	Appendix B	Consultation between Supply and demand parties
9	Outer coating	Appendix C	Consultation between Supply and demand parties
10	Residuals of internal surface cleanliness	Appendix D	Consultation between Supply and demand parties

Table A The Size of Single Double Flaring

Out Dimensions D	Single-Layer expansion diameter D₁	Double-Layer expansion diameter D₂	The minimum length of Double-Layer expansion diameter L	Inner diameter of double-lay expansion D₃	The inner diameter of flaring round corner r
3.18	4.5	5.0	1.0	The maximum size :(D-2S)+0.25 The minimum size:(D-2S)-0.50	1.0±0.3
4.00	5.4	6.0	1.0
4.76	6.3	7.0	1.0
5.00	6.6	7.3	1.0
6.00	7.7	8.4	1.0
6.35	8.1	8.8	1.0
7.94	10.1	10.7	1.6
8.00	10.1	10.8	1.6
9.53	11.8	12.5	1.6
10.00	12.3	13.0	1.6
12.00	14.6	15.2	1.6
14.00	17.0	17.5	2.1
15.88	19.1	19.6	2.1
16.00	19.2	19.7	2.1
18.00	21.5	22.0	2.1
Only to choose one from D₂ and D₃

Table C.1 The Label, Type and the Time of Anti-corrosion Steel Tubes for Refrigeration

Table C.2 The Conversion Film of Copper Tube on Its Label, Type, Typical Appearance and the Time of Anti-corrosion

Label	Type	Typical appearance	The time of anti-corrosion
A	Bright	Transparent, sometimes with a slight blue light	6h
B	Bleach	Transparent and a little iridescence	24h
C	Iridescence	The iridescence of partial yellow	72h
D	Dark color	Oliver green with brown and bronze	96h
E	Composite	Dark	200h
Note: This table is based on chromate conversion film, the use of other treatment methods can be negotiated by both parties

GB24187 Oiled Welded Steel Tube Cold-Drawn Low Carbon Steel Tubes

Precision Steel Tube