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If the metric calcultions (2.27mmm deflection for 6m span 250mm OD steel pipe filled with water) is correct then i might have to relook at my unit conversions. Thanks!

Does this mean that a deflection of 2.27mm is correct for the above parameters? The formula used is for ‘maximum theoretical deflection for a simple span’, for uniformly distributed loads and free ends. This formula is from page 75 of AWWA M11 if you have the book. Metric Y = (5x10^6)/(384) *...

I already multiplied by 9.81 to get the weight in Newtons for the metric formula though.

Hi im trying to understand the formula for pipe deflection in the AWWA M11 page 75. Using the metric formula (7-6M), i calculated the deflection to be 2.27mm for a 6m long 250mm OD steel water pipe with 4.55mm wall thickness. Is this deflection calculation correct? I also cant seem to get the...

Ah i see. As mentioned im more to trying to understand the concept of this. Allowing chambers to settle with the pipe is a good idea. iam very interested on geogrid beddings, any suggestions on where can i read more on this? Perhaps the design guides and examples?

Letting the chambers move with the pipe might work. How about using geotextiles as a reinforcement to the soil? will that help?

Good point LittleInch. I understand that another option is to use piled support when the peat layer is too deep and uneconomicla to replace, have there been cases where geotextiles are used as a replacement for piled supports? Im currently looking for articles and case studies for design and...

Thanks for the reply. Sorry for the misunderstanding. Im more to asking as a general question but maybe i should be more specific. Im looking at larger diameter welded steel pipelines for water suppy e.g above 1000mm. As the valve chambers, blowoff chambers, and anchors are piled while the pipe...

Im relatively new to the water world. For a pressurised steel water supply pipeline laid in relatively soft ground, what is the normal approach to minimize differential settlement between the pipes and chambers and anchor/thrust blocks? Is the option of piling the chambers to a floating length...

Interesting points indeed! Actually we are in the process of finalizing the design for this bridge crossing. Most likely we will be using factory custom flanged bends to maneuver the curve of the bridge. Thanks for the help!

Hi Mr RConner, Thanks for the reply. Will look into the given references for more info. Am i correct to assume these handhole openings will have to be something like a small tee which is to be closed up with a blind flange as opposed to cutting an opening on the pipe itself and welding it back...

Hi Mr Weldstan, Thanks for the reply! The thickness of our 15 inch MSCL is roughly 4.5mm thick. Would this be enough? For your info this mild steel cement lined is used as a water distribution pipeline with roughly 5 bar operating pressures. Do you mind to elaborate further on the weld...

Hi all, I have a question on the effect of welding heat on the internal cement lining of mild steel water pipes. Is it possible for the heat during welding of collars, flanges etc. to damage these cement linings? Currently involved in a project where we have a 15 inch ND MSCL pipe for a...

Interesting points indeed. After several discussions with my superiors we decided that collar, wrappers and crotch plates will not be needed for our case. Referring to the earlier paragraphs before table 13-2 which also can be seen in the above attached, it was mentioned that "For ordinary...

Sorry, I meant 30 inch.

I have a question on mscl water pipe design. For a 30' equal mild steel tee, according to awwa m11 on reinforcing plate design we have to use wrapper plates as the ratio of branch/main diamter is 1.0 (more than 0.7). However looking at the shop drawings given by a few pipe manufacturers they...

Hi, my question is more towards Autodesk Civil 3D and Storm and Sanitary Analysis which is also included. Do bear with the long post :) We are currently trying to model a large sewer network with potentially thousands of incoming sewer flows. Previously the generation of plan and profile...

Thanks for the explanation! I understand the concept now.

Hi, i have a question about air valves. Would somebody explain to me the difference between the large orifice air valve and the small orifice air valve. I understand that the large orifice is meant to allow high volumes of air and water to enter the pipe. However, why is a smaller orifice air...