P9 pipe cap

P9 pipe cap refers to the element used to close the end of the container to isolate the internal and external media, also known as the end cap. The tube cap of a cylinder is generally a rotary shell. According to the shape of the pipe cap surface, it can be divided into convex, tapered, flat and combined shapes. The convex pipe cap refers to the pipe cap whose outer surface is convex, such as semi spherical, elliptical, dish-shaped and non flanged spherical pipe cap. Some gas cylinders use a combined bottom cap with a convex face inward, which can not only protect the strength, but also meet the needs of safe use

Basic Requirements

The existing pipe cap standards are formulated separately according to different structural types (oval, dished, tapered) and forming methods (stamping, spinning), which not only causes the unreasonable phenomenon that the quality requirements of pipe caps in different standards are not all consistent, but also brings some difficulties to the selection of standard pipe caps and the revision of standards

1. The previous pipe cap standards were only matched with GB150 Steel Pressure Vessels, that is, only the manufacturing, inspection and acceptance requirements of pipe caps designed according to rules were considered. China completed the dual track system of basic standards for pressure vessels (with the Analytical Design Standards for Steel Pressure Vessels) as early as 1995, and lacked the pipe cap standards matched with the analytical design, It can not be said that it is a big defect in the standardization of pressure vessels in China

2. GB150 is a mandatory standard, while the pipe cap standard prepared according to GB150 and matched with it is instructive (recommended), which is obviously unreasonable and difficult to protect the quality of pipe cap, an important pressure element

Material analysis of pipe cap

The inner diameter of the vessel Di=4000mm, the calculated pressure Pc=0.4MPa, the design temperature t=50 ℃, the pipe cap is a standard oval pipe cap, the material is 16MnR (the allowable stress of the material at the design temperature is 170MPa), the negative deviation of steel is not more than 0.25mm and not more than 6% of the nominal thickness, the corrosion allowance C2=1mm, and the welding joint coefficient of pipe cap butt welding= 1。 Calculate the calculated thickness, design thickness and nominal thickness of elliptical pipe cap