Sloping steam pipe on long pipe rack

[kcjaz]

I have a project that involves a long steam pipe run from a power plant to an off site steam host. The distance is about 1/2 mile and the current concept is to use a pipe rack. This is multiple steam lines and different pressures. The steam is high pressure with superheat (not saturated "wet" steam). We would normally slope steam lines in the direction of flow at 1/8" per foot (1%) but for a long horizontal distance this becomes difficult, especially on a rack.

I have read some old posts on this topic that essentially concluded with pipe racks may not be the best solution for long steam lines requiring slope. I agree with this but there are some good reasons a rack is desired in this case. What we have currently designed is mostly a flat (no slope) line with drip pots every 300' or so and at every major change in direction. My opinion is that there are as many opinions on how best to handle this situation as there are engineers with opinions. What I am looking for are some actual project examples so I can make a judgement on "industry practice".

Does anyone have actual project examples that I could follow up on to help me get an idea of what is being done out there in the real world?

 

[pennpiper]

A good source might be Cities, Industrial Parks or Military installations with central Steam Plants that require vast distribution systems.

Check the following:
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http://www2.spiraxsarco.com/resourc...eam-distribution/steam-mains-and-drainage.asp

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http://www.cospp.com/articles/print...ding-kodak-s-giant-industrial-park-plant.html

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https://books.google.com/books?id=X...trial park central steam distribution&f=false

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https://www.google.com/search?q=Mil...niv&sa=X&ei=5ID8VLuKGcKdNvL5gugJ&ved=0CB8QsAQ

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http://ucrtoday.ucr.edu/7282

Sometimes its possible to do all the right things and still get bad results

 

[racookpe1978]

Worldwide, I have only seen long-distance steam lines run at ground level - on the ground following the terrain using low pipe stands on simple concrete pads, periodically anchored against movement with additional heavier concrete pads - with periodic "vertical loops" to allow anchors for expansion and contraction.

The result, of course, is "trapped" low points between each vertical loop. But those traps allow convenient points to blow out the condensate regardless of whether the overall line is going uphill or downhill. Sideways expansion loops are just not regularly seen - maybe because the right-of-way near roads or because it is easier to plan a constant "width" piping drawing in the old days of manual drafting?

The vertical loops over roads and railroads always have used specific "bridges" - I have not seen tension wire supporting pipes except over rivers.