Cylinder

CYLINDER (or Carboy), a vessel for storing liquids and compressed gases. 1) For storing and transporting acids, alkalis, etc., glass cylinders of cylindrical or spherical shape with a capacity of 30–50 liters are used. These cylinders are usually inserted into a wicker basket with straw to protect them from accidental impacts and breakage. For ease of pouring, the basket with the cylinder is sometimes suspended from a metal stand, in which, with the help of a long lever, the cylinder can be tilted to any angle to gradually pour out the liquid. For pouring small portions of liquid, siphons of various designs are used. Very convenient are cylinders equipped with a stopper with an outlet glass tube for pouring out liquid displaced from the cylinder by compressed air. For pouring liquid from narrow-necked cylinders, a stopper with a short, curved, wide tube for the liquid outlet is used, with a longer and narrower tube inserted into it for air to enter the bottle, or a glass tube curved upwards is inserted into the neck of the tilted cylinder, through which air enters the cylinder, while the liquid pours out directly from the neck. 2) For collecting acids (hydrochloric and nitric) during their manufacture, cylinders in the form of three-necked vessels made of well-fired clay are used. 3) Cylinders for compressed gases are steel cylindrical vessels made from seamless pipes; they must possess great strength and airtightness, as they are intended for the storage and transportation of gases compressed under high pressure, such as, for example, H, O, CO₂, CO, Cl, acetylene, ammonia, etc. The lower part of the gas cylinder is equipped with a shoe-stand, on which the cylinder is placed during operation; the upper part ends in a valve for releasing gas. For releasing gas in a thin stream, so-called reduction or regulating valves are used. The simplest of these is the Le Rossignol valve, made of bronze and nickeline. To avoid accidental mixing of different gases in the same cylinder, which often served as a cause of destructive explosions, the fittings of cylinders for combustible gases (H, CO, etc.) have a left-hand thread, and for non-combustible gases (O, CO₂, NH₃, etc.)—a right-hand thread. The external distinction between cylinders containing different gases is their coloring in different colors: for O—blue, for H—red, for acetylene—white, for Blau gas—green, for NH₃—yellow, for all others—black. The capacity of ordinary, double, and triple cylinders is 14, 28, and 42 liters. At a pressure of 125 atmospheres, such cylinders contain 1.75, 3.5, and 5.23 cubic meters of gas. The weight of an empty cylinder is about 24–62 kg. Cylinders put into operation are subjected to a preliminary hydraulic test at 225 atmospheres, repeated, according to the decree of the People's Commissariat of Labor, every 3 years. After testing, a stamp is placed on the cylinder indicating the time and place of testing, capacity, and pressure. Filled cylinders must be protected from heating by sunlight, protected from mechanical shocks and impacts, and must not be stored near fire or heated objects. Cylinders for O, especially their valves, must be carefully protected from contamination with fats and oils, because, due to friction when closing or opening the valve, in the presence of O, ignition of fat or oil is possible, which could lead to a destructive explosion. The requirements that cylinders put into operation must satisfy and the rules for their operation constitute the subject of a special decree of the People's Commissariat of Labor: "Rules for the construction, maintenance, and inspection of cylinders (vessels) for compressed and liquefied gases," approved by the People's Commissariat of Labor of the USSR on January 7, 1925, and published in "Izvestiya NKT SSSR" for 1925, No. 2–3.

S. Bruyevich.