(1) Nominal working pressure of gas cylinder
For cylinders containing permanent gas, the nominal working pressure refers to the limited filling pressure of the gas contained at the reference temperature (usually 20°C). For gas cylinders containing liquefied gas, the nominal working pressure refers to the upper limit of the gas pressure in the cylinder when the temperature is 60°C.
According to the regulations of "Gas Cylinder Safety Supervision Regulations" (Guofa [2000] No. 250 of the Quality and Technical Supervision Bureau), the nominal working pressure of gas cylinders has been serialized. The nominal working pressure of gas cylinders containing high-pressure liquefied gas shall not be less than 8MPa. For gas cylinders containing toxic and highly toxic liquefied gases, the nominal working pressure should be appropriately increased.
(2) Hydraulic test pressure, design pressure and allowable pressure
The hydraulic test pressure of the steel gas cylinder is the pressure test pressure to check the strength of the gas cylinder. It is stipulated that the hydraulic test pressure of the cylinder is 1.5 times the nominal working pressure.
The design pressure of the steel gas cylinder is the pressure used to design and calculate the wall thickness of the cylinder body, and the design pressure is equal to the hydraulic test pressure.
The allowable pressure of the gas cylinder is the maximum pressure that the gas cylinder is allowed to bear, and it should not be less than the medium pressure of the medium in the bottle at 60°C. The allowable pressure of the steel gas cylinder shall not exceed 0.8 times the hydrostatic test pressure.
(3) The nominal volume of the gas cylinder
The nominal volume of the gas cylinder refers to the grading series of the gas cylinder volume specified by the gas cylinder regulations and standards. The nominal volume and the nominal working pressure are a nominal value, not an accurate actual value. To be a safety gauge, the actual volume of the gas cylinder must be greater than the nominal volume with a tolerance of +5%. It can be seen that although the nominal volume is the nominal value of an appellation, it is strictly limited and cannot be called casually. For example, a seamless gas cylinder with a nominal volume of 40L should have an actual volume between 40L and 42L.
In order to facilitate management, my country divides the nominal volume of gas cylinders into three categories: large, medium and small: small volume below 12L (including 12L), medium volume above 12L to 100L (including 100L), and large volume above 100L.
The volume of steel seamless gas cylinders is the most common with 40L gas cylinders, but there are also as small as 0.4L to 80L.
The volume of steel welded gas cylinders, as dissolved acetylene cylinders, is the most common with 40L cylinders, and liquid ammonia and liquid chlorine cylinders are most popular with 800L and 400L. Because according to the filling factor of 1.25 kg/L of liquid chlorine, their medium mass is exactly 1 t and 0.5 t.
The volume of the liquefied petroleum gas cylinder is 35.5L. Because the filling factor of 0.42 kg/L is calculated, this kind of gas cylinder is filled with 15 kg of LPG, which is the consumption of an average family in one month.
(4) The maximum operating temperature and the minimum operating temperature of the gas cylinder
The maximum operating temperature of the gas cylinder refers to the highest temperature that the gas cylinder may reach after being filled with gas. According to "Seamless Steel Gas Cylinder" (GB 5099-1994), "Steel Welded Gas Cylinder" (GB 5100-2011) and "Gas Cylinder Safety Supervision Regulations", 60°C is the maximum operating temperature for gas cylinders. -40°C is the minimum operating temperature for gas cylinders.
(5) The color of the gas cylinder
The Color of Gas Cylinders (GB 7144-1999) clearly stipulates the color of gas cylinders. For example: acetylene cylinders are white, nitrogen cylinders are black, oxygen cylinders are light blue, ammonia cylinders are light yellow, carbon dioxide cylinders are aluminum white, etc.
