1. Scope

This japanese Industrial Standard specifies the carbon steel pipes, hereinafter referred to as the "pipes", used for pressure service at an approximate maximunn temperature of 350℃. The pipes for high pressure sevice shall be in accordance with JIS G 3455.
 Remarks
1. Pertaining to the electric-resistance welded steel tubes, when previously agreed upon wiht the manufacturer, the purchaser may designate the supplementary quality requirements Z 3 or Z 4 specified in Appendix, in addition to the items specified in this text.
    Appendix Z 3 Ultrasonic Examination
    Appendix Z 4 Eddy Current Examlnation
   2. The units and numerical values given in { } in this Standard are based on the international System of Units (SI) and are appended for informative referencw.

Further, the traditional units accompanied by numerical values in this Standard shall be converted to the SI units and numerical values on Jan. 1, 1991.

2. Grade and Designation

The pipe shall be classified into two grades and their letter symbols shall be as given in Table 1-1 or Table 1-2.

Table1

3. Method ofManufacture.

4. Chemical Compostion

The pipe shall be tested in accordance with 9.1 and the ladel analysis values obtained shall conform to Table 2-1 or Table 2-2.

Table 2

Letter symbol of grade	Elongation %
	C	Si	Mn	P	S
STPG 370	0.25 max.	0.35 max.	0.30 to 0.90	0.040 max.	0.040 max.
STPG 410	0.30 max.	0.35 max.	0.30 to 1.00	0.040 max.	0.040 max.

5. Mechanical Properties

6. Hydrostatic Test of Nondestructive Test

The pipe shall be tested in accordance with 9.5 and the resulting hydrostatic characteristic or nondestructive characteristic shall conform to either of the following two. The preference for which of them shall be left to the specification by the purchaser or to the discretion of the manufacturer.

6.1 Hydrostatic Test when a hydrostatic pressure specified in Attached Table 1-1 or 1-2 is applied, the pipe shall withstand it without leakage.
  6.2 Nondestructive Test A nondestructive examination by either an ultrasonic test or an eddy current test shall be made on the pipe, and there shall be no signal greater than those produced by the artificial defects of the reference test block of division UD of the working sensitivity specified in JIS G 0582 or of divisionEY of the working sensitivity specified in JIS G 0583

Hydrostatic Test Pressure          Unit : kgf/㎠{bar}

Schedule number Sch	10	20	30	40	60	80
Hydrostatic Test Pressure	20 {20}	35 {34}	50 {49}	60 {59}	90 {88}	120 {118}

Remark:   1 bar=10⁵Pa

7. Appearance
  7.1 The pipe shall be practically straight, and its both ends shall be at a right angle to its axis.
  7.2 The inside and outside surfaces of the pipe shall be well-finished and free form defects that are detrimental to practical use.

8. Dimensions, Mass and Dimensional Tolerances

9. Test

10. Inspection

11.Reinspection  

The pipe may be determined for final acceptance by a retest specified in 4.4 in JIS G 0303.

12. Marking

Each pipe having passed the inspection shall be mrked with the following items. Howver, the smaller pipes or other pipes specified by the purchaser may be bundled together and marked for each bundle by a suitable means. In both cases, the order of arranging the marked items is not specified.

When approved by the purchaser, a part of the items may be omitted.

(1) Letter symbol of grade
  (2) Letter symbol indicating the manufacturing processes(3)
  (3) Dimensions(⁴)
  (4) Manufacturer's name or its identifying brand
  (5) Letter symbol denothing the supplementary quality requirement, Z
Note(³)
  The letter symbol indicating the manufacturing processes(3) shall be as follows, provided that the dash may be omitted leaving a blank.

Hot-finished seamless steel pipe - S - H
  cold-finished seamless steel pipe- S - C
  Electric resistance welded steel pipe other than hot-finished and cold -finished ones - E - G
  Hot-finished electric resistance welded steel pipe- E - H
  Cold-finished electric resistance welded steel pipe - E - C
Note(⁴)
  The dimensions shall be expressed as follows.
  Nominal diameter × Nominal wall thickness
  Example: 50A × Sch 40 , 2 B × Sch 40

13. Report 

The manufacturer shall submit the test report when previously required by the purchaser.

<< BACK