60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
(OP)
Task is to design a 60 ft span, simply supported, pipe using 20 ft sections and mechanically fastened connections (flanged pipes) to create fixity.
I was looking to DIPRA website for guidance, but the "ductile iron on supports" brochure only supports 20 ft sections with 20 ft support spacing....
Where can I find guidance on concentrated stresses at connections? Thermal effects?, since the "longitudinal" movement will be restrained from the fixed connection.
(I've left a message with the DIPRA regional engineering office and am waiting to hear back)
Thanks!
I was looking to DIPRA website for guidance, but the "ductile iron on supports" brochure only supports 20 ft sections with 20 ft support spacing....
Where can I find guidance on concentrated stresses at connections? Thermal effects?, since the "longitudinal" movement will be restrained from the fixed connection.
(I've left a message with the DIPRA regional engineering office and am waiting to hear back)
Thanks!






RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
The stresses / deflections on the gross section are ok. My heffe just wanted me to consider the stresses at the flange / bolted connection, which will be 10 ft off of C.L. of span.
No, arch is not acceptable.
Additional info: One end is free (it turns down and dumps into a tank), so thermal effects are negligible.
RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
You should be able to calculate an allowable end force on the flanges due to pressure, and then an equivalent moment to give the same longitudinal stress in the pipe. Assuming pressure is pretty well zero when loaded, you could then design for that end force.
Long unsupported pipes can vibrate in the wind.
RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
RE: 60 FT SPAN IRON/STEEL PIPE WITH 3 - 20 FT SECTIONS
This situation can be modeled fairly easily in most structural programs and is covered by most piping software as well. The flanges should be stiff enough to prevent any transfer of prying forces. In essence the flanges will then behave like spring supports as far as radial pressures are concerned.
Depending on pipe size, a secondary support system may be a waste of time and effort.