The 90 degree elbows are used to connect tubes at a 90° angle. As the name suggests, the elbow is always a right-angle in shape. Such type of elbow is also known as "90 bends or 90 ells". This is a pipe fitting device that is bent in such a way to produce a 90° change in the direction of flow of the fluid/gas in the pipe. The elbow is used to change the direction in piping and is also sometimes called a "quarter bend".
http://www.zhijusteel.com/elbow/90-degree-elbow/

Bismuth-based: Bismuth alloys will have a composition that is less of a ductile characteristic than tin, as it can become brittle. Manufacturers use bismuth due to its expansion qualities when it melts and then solidifies as it can expand to up to 3.3%. The more bismuth is in an alloy, the more it expands. It is less expensive than other alloys that are featured and the least toxic as it can be used in applications where there is drinking water present. ;
http://www.wocmetal.com/low-me....lting-alloys/bismuth

A properly functioning HVAC system is essential to a comfortable home. While many people know how to operate their AC system, very few people know how it actually works. Your AC’s return air vent is a critical component of an HVAC system and serves several purposes. Not only do return air vents maintain your home’s air pressure and filter out debris, but they can also serve to save you on energy costs and expenses.
http://www.sxcanreal.com/return-air-vent/

The sounds available to you when you play are not limited to what you do with your hands. Piano pedals (the levers at your feet) enrich the sound in various ways, opening out possibilities further than the keyboard, from subtle nuances in dynamic to bold changes in the tone.
http://www.sihaimetal.com/piano-pedal/

The BLAUPUNKT Multifunctional electric hot pot is different from traditional hot pots in that it is a hot pot that can be controlled by lifting and lowering. When the food is cooked, the user can manually control the built-in strainer tray to lift upwards and separate the food from the stock. It also comes with two different baking trays for five different cooking practices. It is perfect for use in scenarios such as family gatherings, outdoor picnics, and gatherings with friends.
http://www.ougebbq.com/electri....c-hot-pot/multifunct