GB/T 33147-2016 in English

3.1 Material requirements

According to clause 5.1 of the standard, the main material of the cylinder must be killed steel smelted in an electric furnace or converter, and have good stamping and welding properties. The allowable deviation of the chemical composition of the material shall comply with the provisions of GB/T222, and the yield strength ratio (Re L/Rm) shall not exceed 0.80.

3.2 Design requirements

Clause 7.1 of the standard stipulates that steel cylinders with a nominal volume of less than or equal to 40L are composed of two parts and a single girth weld; while steel cylinders with a nominal volume greater than 40L are composed of three parts, with two girth welds and one longitudinal weld. The design wall thickness calculation formula is shown in formula (1) and formula (2), and it is necessary to ensure that the material thickness meets the requirements of GB/T1804.

3.3 Manufacturing process

The cylinder head must be pressed and formed by a whole piece of steel plate, and the upper head should be pressed with the embossed word "DME" and manufacturing information. The cylinder is made of steel plate rolled and welded, and the longitudinal weld misalignment must meet ≤0.1S0 (Figure 2), and the welding is carried out by automatic welding process.

3.4 Test method

The water pressure test pressure is 2.4MPa, and it is kept for 1 minute without leakage. The air tightness test is carried out twice, the first time at 0.5MPa before spraying, and the second time at 1.6MPa after the cylinder valve is installed. The radiographic inspection is required to meet the Class III qualification standard.

3.5 Marking and Safety

The surface of the cylinder is coated with epoxy resin coating with a thickness of ≥50μm, and the manufacturing mark and the "Outdoor Use Only" prompt are embossed. The product certificate must indicate the valve model and manufacturing unit information.