New product announcements: 09/02/2009 Welding Respirator: Lightweight Design The Powered Air Purifying Respirator provides a clean supply of air to welders in a fully portable system. The PAPR has a 3.5-lb blower that is worn on the back with shoulder straps. It has a built-in HEPA filter and features two air speeds to adjust the volume of air to suit conditions. The blower supplies air to an included Elite helmet. The helmet features auto-darkening cartridges and a lightweight design. The system is powered by a lithium-ion battery with an 8-hour battery life. Miller Electric Mfg. Co.; 920-734-9821; www.millerweld.com Pipe Hanger: Quick
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.