Cylinder testing (Hydro Testing)
Hydro Testing of Cylinders, which is also known as the hydrostatic stretch test is the process of testing majorly all the Gas Cylinder except Acetylene (such as Oxygen, Argon, Nitrogen, Hydrogen, Carbon Dioxide, Calibration Gases, Gas Mixtures, and any other Seamless or Welded gas Cylinders irrespective of Cylinder MOC ) for strength and possible leaks. Periodical Hydro testing is often required to validate that the cylinder is working in the proper condition and is suitable to be used in the future for a further specified period.
As per the guidelines of Petroleum & Explosives Safety Organisation, (PESO), it is mandatory for every High-Pressure Seamless Cylinder to undergo Periodical Hydro Testing Process after an interval of 5 years, or in-between as and when the need arises depending upon the existing condition of the cylinders. Some Gas Cylinders like CNG & Toxic Gases etc, needs to be Periodically hydro tested every two years or after an interval as specified by PESO / BIS.
A cylinder is Normally Periodically Hydraulically Tested at a pressure (called Test pressure) which can be 1.5 times or 1.66 times of working pressure depending upon the manufacturing standard of the cylinder and its MOC. Periodic Hydro testing is carried out to check the elasticity of the cylinder material. Every cylinder material undergoes elastic stress/expansion during each gas filling process. With time and repetition, this elasticity goes on deteriorating, which is undesirable for safety reasons. This is the reason we need to check the cylinder for its elasticity i.e to check that after releasing the test pressure, the material of the cylinder gets back to its original position within the specified tolerance limits or not.
This testing procedure results are measured in terms of Percentage Permanent Expansion and shall fall in the certain prescribed limit as per the guidelines of PESO.
Industrial Uses of Oxygen
Oxygen is used with other fuel gases in multiple industries such as in gas welding, oxygen scarfing, gas cutting, flame cleaning, flame hardening, and flame straightening. High quality of oxygen must be used in gas cutting to ensure clean and high- speed cut.
Oxygen is also used as a bleaching chemical. In the manufacturing of high-quality bleached pulp, the lignin should be removed in the bleaching process. Chlorine has been used for this purpose but new processes using oxygen reduce water pollution. Oxygen plus caustic soda can replace hypochlorite and chlorine dioxide in the bleaching process, resulting in lower costs.
oxygen is used heavily in the steel-making process. Unwanted carbon combines with oxygen to form carbon oxides, which leave as gases in the steel-making process. Oxygen is also used in making other metals such as zinc, copper, and lead.
Medical oxygen gas cylinder has high purity oxygen that is utilized for medical analysis that is developed for use in the human body. Medical oxygen gas cylinders contain a high virtue of oxygen gas; no different kinds of gases are permitted in the cylinders to anticipate contamination. There are extra prerequisites and rules for medical oxygen, including requiring an individual to have a prescription to arrange or order medical oxygen.
Cylinders are used to store oxygen gas for –
- Breathing at medical facilities like emergency Hospitals, clinics and at home and oxygen
- Utilized during anesthesia, medical aid revival for
- life support for patients who can’t inhale all alone, and oxygen
- Scuba sets: open circuit demand and
- For mountain
- provide life support for artificially ventilated patients
- aid cardiovascular stability
Usually, Oxygen is delivered in bulk to the hospitals in liquid form. Portable non-cryogenic air separation units are widely used in home care. Larger units of non-cryogenic air separation are used in remote/small hospitals where delivery of liquid oxygen is costly and demand is high. These units typically produce up to 93% purity oxygen.
Some Other Common Uses and Applications in Industries
- As breathing gas vital to the need of any living being.
- As a mixing gas in metal cutting or brazing or welding process when mixed with Acetylene or LPG/Propane/Butane.
- As an assist gas in Plasma Cutting or laser cutting
- As an impurity remover in smelting process. Helps in removing impurities of sulphur and carbon from the molten metal during the making of steel from iron
- As a rocket fuel in aeronautical or spacecraft industry.
- As a main reactive agent in many chemical industries to make various industrial or lab grade chemicals like Ethylene Oxide, Glycols and
- As a main constituent to increase production and decrease impurities of NOx in Glass manufacturing
- In laboratory