Cangzhou Shengtai Pipeline Co.,Ltd

Add: Hi-tech Industrial Development Zone, Cangzhou City, Hebei Province, China.

Tel: +86-317-3777977, +86-317-377787

E-mail: sara@heb315.com ; anny@heb315.com ; david@heb315.com ;sales@heb315.com

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Seamless steel pipe used for gas cylinder (GB 18248-2008)
Mar 30, 2018

Seamless steel pipe material used for gas cylinder is 37Mn,34Mn2V,30CrMo,35CrMo,34CrMo4 and 30CrMnSiA.

Specification

Unless otherwise stipulated in the contract. Steel pipe delivery is according to nominal   outside diameter (D) and nominal wall thickness (S). Through consultation between the two parties, it also can be according to nominal outside diameter   and min wall thickness (Smin).

Steel pipe outer diameter and thickness should meet the stipulation of GB/T17395.

Allowable   tolerance of outer diameter and thickness

      Type

    Steel pipe

 manufacturing

      method

  Range of

      sizes

      /mm

   Outer

diameter

allowable

tolerance

       /%

              Wall thickness 

      allowable tolerance/ %

      Common

           level

    High

    class

Use   nominal outside diameter and nominal wall thickness

Hot   rolling

(expanding)

D﹤339.7

±1

+12.5

-10

±10

D≥339.7

+15

-12.5

+12.5

-10

Cold   rolling

(drawing)

all

±0.75

±10

±7.5

Use   nominal outer diameter and minimum wall thickness

Hot   rolling

(expanding)

D﹤339.7

±1

+25

0

+22.5

0

D≥339.7

+30

0

+25

0

Cold   rolling

(drawing)

all

±0.75

+22.5

0

+15

0

Steel pipe wall thickness allowable   tolerance usually to be delivery according to common level precision. It also can be delivery according to high class precision  after negotiation.

Length and tolerance

The usual length of steel pipe is 4000~12000mm. Through negotiation, the steel pipe delivery length can be ﹥12000mm or shorter than 4000mm, but not shorter than 3000mm. But the quantity of steel tube length shorter than 4000mm should   not exceed 5% of the total quantity of the steel pipe.

According to negotiation, it can also be delivered according to fixed length or double length. The fixed length of the steel pipe shall be within the usual length. The length allowable tolerance is +10mm when length ≤6000mm. When length ﹥6000mm, allowable tolerance is +20mm. Each double length should leave cut margin according to stipulation as below: Outer diameter ≤159mm, 5~10mm; Outer diameter ﹥159mm, 10~15mm.

 


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