Standard 90° bend

The SCCG data shown in this section have been determined experimentally. Static and constant stress rate strength tests have been performed on standard bend specimens (3 x 4 x 45 mm ) of a commercial 99.7% AI2O3 (Frialit-Degussit F99,7 Friatec AG, Mannheim, Germany) in four-point flexure [99]. All experiments were conducted at room temperature in laboratory air. 

Dimpting limits, H/R, for various bend anises above and below standard bend an e... 

Specifications, Standards, Quality Control, and Health and Safety Factors. Formerly, there was an Insulation Board Institute representing the insulation board industry, but the decline in the market and number of producers has led to its demise. Currently (ca 1997), the industry is represented by the American Hardboard Association (AHA). Specifications and standards are found in American National Standards Institute (ANSI) standard for CellulosicFiberboard (7). The standard includes descriptions of the various types and classes of ftberboard, as well as requirements for physical and dimensional stabiUty properties. QuaUty control tests are limited to a few basic strength and stabiUty tests, including bending strength, bond strength, and moisture resistance. 

Pressure- Vessel Standards. Explosion-clad plates for pressure vessels are tested according to the appHcable ASME Boiler and Pressure Vessel Code Specifications. Unfired pressure vessels using clads are covered by ASTM A263, A264, and A265 these include tensile, bend, and shear tests (see Tanks AND pressure vessels). 

Refractoriness. Refractoriaess is determined by several methods. The pyrometric cone equivalent (PCE) test (ASTM C24) measures the softening temperature of refractory materials. Inclined trigonal pyramids (cones) are formed from finely ground materials, set on a base, and heated at a specific rate. The time and temperature (heat treatment) requited to cause the cone to bend over and touch the base is compared to that for standard cones. 

Years of development have led to a standardized system for objective evaluation of fabric hand (129). This, the Kawabata evaluation system (KES), consists of four basic testing machines a tensile and shear tester, a bending tester, a compression tester, and a surface tester for measuring friction and surface roughness. To complete the evaluation, fabric weight and thickness are determined. The measurements result in 16 different hand parameters or characteristic values, which have been correlated to appraisals of fabric hand by panels of experts (121). Translation formulas have also been developed based on required levels of each hand property for specific end uses (129). The properties include stiffness, smoothness, and fullness levels as well as the total hand value. In more recent years, abundant research has been documented concerning hand assessment (130—133). 

Cascade coolers are a series of standard pipes, usually manifolded in parallel, and connected in series by vertically or horizontally oriented U-bends. Process fluid flows inside the pipe entering at the bottom and water trickles from the top downward over the external pipe surface. The water is collected from a trough under the pipe sections, cooled, and recirculated over the pipe sections. The pipe material can be any of the metallic and also glass, impeiMous graphite, and ceramics. The tubeside coefficient and pressure drop is as in any circular duct. The water coefficient (with Re number less than 2100) is calculated from the following equation by W.H. McAdams, TB. Drew, and G.S. Bays Jr., from the ASME trans. 62, 627-631 (1940). 

---