By what principle does the pressure in the domestic hot water system change?
Greetings. Briefly about the problem. The system for supplying hot water to my homes is organized according to a deadlock. Single tube. The problem is that even when all branches to residential buildings are blocked, a cyclical change in pressure, swaying occurs in the highway. And accordingly, when booster pumping stations in residential buildings etc. are operating normally, due to the buildup of pressure on the supply (city) highway, they cannot provide stable supply to the apartments.
The supplier of hot water for a long time convinced us of the incorrect settings of house-building booster stations. But in the end, having gone to our houses, and having completed the outages, which I write about at the beginning of the letter, I became convinced that the problem was on their mains.
In their boiler room at the supply after the pump station, the pressure is stable at 4.5 points and does not change. Where to look for hydraulic fineness?
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Hello! In the DHW system, a decrease in hydrostatic pressure is observed in the direction of the moving flow. Pressure instability may be due to the limited capacity of the main water supply.
The insufficient pipe throughput can be explained by:
1. An increase in the number of consumers.
2. Initially incorrectly performed hydraulic calculation of the pipeline.
3. Malfunctioning valves, incomplete opening.
4. Debris entering the hot water supply network.
5. Reducing the internal section of the pipes as a result of the deposition of lime on their walls, as in the photo.
When narrowing the internal clearance, not only the throughput of the pipes decreases, but also the roughness coefficient increases and, as a result, the hydraulic resistance of the system becomes large.