An elbow is a pipe fitting installed between two lengths of pipe or tubing to allow a change of direction, usually a 90° or 45° angle, though 22.5° elbows are also made.
The ends may be machined for butt welding, threaded (usually female), or socketed, etc.When the two ends differ in size, the fitting is called a reducing elbow or reducer elbow. Elbows are categorized based on various design features as below: Long Radius (LR) Elbows ? radius is 1.5 times the pipe diameter Short Radius (SR) Elbows ? radius is 1.0 times the pipe diameter 90 Degree Elbow ? where change in direction required is 90° 60 Degree Elbow ? where change in direction required is 60° 45 Degree Elbow ? where change in direction required is 45° A 90 degree elbow is also called a "90 bend" or "90 ell".
It is a fitting which is bent in such a way to produce 90 degree change in the direction of flow in the pipe.It is used to change the direction in piping and is also sometimes called a "quarter bend".
A 90 degree elbow attaches readily to plastic, copper, cast iron, steel and lead.It can also attach to rubber with stainless steel clamps.
It is available in many materials like silicone, rubber compounds, galvanized steel, etc.The main application of an elbow (90 degree) is to connect hoses to valves, water pressure pumps, and deck drains.
These elbows can be made from tough nylon material or NPT thread.Źródło: https://en.wikipedia.org/wiki/Piping_and_plumbing_fitting
To define and secure boilers safely, some professional specialized organizations such as the American Society of Mechanical Engineers (ASME) develop standards and regulation codes.
For instance, the ASME Boiler and Pressure Vessel Code is a standard providing a wide range of rules and directives to ensure compliance of the boilers and other pressure vessels with safety, security and design standards.5 Historically, boilers were a source of many serious injuries and property destruction due to poorly understood engineering principles.
Thin and brittle metal shells can rupture, while poorly welded or riveted seams could open up, leading to a violent eruption of the pressurized steam.When water is converted to steam it expands to over 1,000 times its original volume and travels down steam pipes at over 100 kilometres per hour.Because of this, steam is a great way of moving energy and heat around a site from a central boiler house to where it is needed, but without the right boiler feed water treatment, a steam-raising plant will suffer from scale formation and corrosion.
At best, this increases energy costs and can lead to poor quality steam, reduced efficiency, shorter plant life and unreliable operation.At worst, it can lead to catastrophic failure and loss of life. Collapsed or dislodged boiler tubes can also spray scalding-hot steam and smoke out of the air intake and firing chute, injuring the firemen who load the coal into the fire chamber.
Extremely large boilers providing hundreds of horsepower to operate factories can potentially demolish entire buildings.Źródło: https://en.wikipedia.org/wiki/Boiler#Safety.