Analysis of methods of hydraulic calculation of pressure pipelines made of polymer materials

Summary

The analysis of the most pressing for today methods of hydraulic calculations used in domestic design of pressure pipeline systems made of polymer materials was carried out. The methods of hydraulic calculation of pressure pipes were considered on the basis of: pipe friction number formula for hydraulically smooth pipes suggested by F. A. Shevelev; Kolbruk formula (widely used overseas); formula suggested by A. Ia. Dobromyslov. The analysis of the methods was carried out in relation to the applicability and validity of the results of the hydraulic calculations of pressure pipelines. The aim of the analysis was to assist the designer in choosing the most comfortable method of hydraulic calculations of pressure pipes made of polymer materials.

Key words

polymeric materials , hydraulic design , pressure pipeline , calculation method , validity of calculation method

Designing pressure and vacuum public sewers

Summary

In Russia until recently only gravity sewers have been used for public sewers. With advent of sparsely populated territories of low-rise development the gravity sewers become unreliable and require high operational expenditures; therefore, pressure and vacuum public sewers are used with increasing frequencies. Because of the high flow rate and turbulence the threat of blockage of these pipelines is low. In vacuum sewers wastewater is aerated; therefore no corrosion occurs. Comparing to the expenditures for a free slope sewer the construction the costs saving in case of a vacuum sewer amounts up to 50%. Pressure sewer includes receiving tanks, mini sewage pumping stations, air-blowing (compressor) stations, pressure pipelines with valves and fittings. Vacuum sewer includes curtilage chambers, collecting pipelines and a vacuum station combined with a sewage pumping station. The formulas for pump capacity calculations are presented. The examples of lay out solutions are given.

Key words

treatment facilities , pumping station , sewerage system , vacuum station , air-blowing (compressor) station , suction valve , water seal