Answer to Question #269910 in Chemical Engineering for Amar

Question

A pipe of 6.5 cm outside diameter is covered with 5 cm (thickness) of asbestos layer

(conductivity = 0.12) and 4 cm (thickness) layer of cork (conductivity = 0.03). If the

temperature of outer surface of the pipe is 150 0 C and the temperature of the outer surface of

the cork is 35 0 C. Calculate the heat loss in W/m 0 C.

Answer 1

When specific pipes are specified, the NPS, Schedule, and material are required. Outside of North America, pipes are identified by Diametre Nominel (DN), which is a dimensionless value that roughly equates to the outside diameter of the pipe in mm. The DN dimensions must conform to ISO Standard 6708.Steel Pipe Sizes - Schedule 40 NPS Outside Diameter (in) Inside Diameter (in) Wall Thickness (in) Weight (lb/ft) 16 16.000" 15.000" 0.500" 82.77 lb/ft 18 18.000" 16.876" 0.562" 104.70 lb/ft 20 20.000" 18.812" 0.594" 123.10 lb/ft 24 24.000" 22.624" 0.688" 171.30 lb/ft 19 more rows