Connection issues for pipes laid in trenches
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As the title indicates, gasoline pipelines with a working pressure of less than 0.5 MPa are laid in trenches. The trench is not straight; it has a slight curvature, with a radius of curvature of about 200 meters. Questions: 1. Are the pipes in the trench (DN150) welded together as straight sections, or are they bent into a certain arc shape? 2. The trench is approximately 500 meters long; how should drainage within the trench be handled? I hope those with engineering experience can offer some guidance; thank you. . . .
You can take a look at the regulations for gas stations.
1. The pipe is divided into sections; a bevel is created at the weld points – it doesn’t need to be very large, just enough for welding. The pressure is not high, so it’s quite simple. The resulting shape is similar to that of dried shrimps, only without such a large angle. 2. A gap of 300–500 units should be maintained between the bottom of the pipe and the bottom of the trench. The slope at the bottom of the trench should be adjusted; since the pipe trench is long, it can be divided into several sections, with lower points created at those sections, and floor drains can be installed at those lower points to facilitate drainage.
Just cover it with a lid without backfilling sand – is that okay? . . . .
I found a book on oil pipelines, which states that an angle of less than 3° at the joint of the pipes is sufficient. Also, if water drains out through the floor drain, is it necessary to have a collection pit with separate channels for rainwater and sewage? Thank you. . .
I’m not sure where the wastewater goes. Given the possibility of leaks, I think it needs to be treated as oily wastewater. How is the rainwater drained? Through valves? I don’t understand
Firstly, the trench should be covered with a lid; secondly, trenches for oil and gas lines are generally required to be filled with sand nowadays. For drainage, there should seem to be a visible low point for easy observation.
With a radius of 200 meters, the pipes are difficult to bend; therefore, they can be welded in a polygonal shape to accommodate the curvature of the trench. It is best not to fill the trench – a cover plate can be used instead. At the end of the rainwater drain, a shut-off valve should be installed, so that rainwater flows into the main rainwater system when in rainwater condition, and sewage flows into the sewage system when in sewage condition
The pipelines are at the dock; there’s no sewage collection tank. Should one be built? Fish always knows what to do. . . . .