Controversial issues of improving the regulatory framework governing the design, construction and operation of gravity wastewater disposal systems

Summary

In recent decades, the integrity health of sewer pipelines has been deteriorating in the cities of the Russian Federation. The increasing rate of wear and tear and unsatisfactory integrity health of a considerable number of sewers, the need to ensure the reliability and environmental safety of the pipelines, and limited material resources for their rehabilitation and renewal in the context of housing and utilities reform require a scientifically proved approach to solve these problems. Choosing the technologies of pipeline rehabilitation in order to improve their reliability requires improving the regulatory documents (in particular, CP 32.13330.2018 «Sewerage. External networks and structures») that regulate the requirements for newly built and reconstructed wastewater disposal systems. The federal legislation establishes the minimum threshold requirements for buildings and structures (including the networks and engineering infrastructures in them), as well as for the design, construction, operation and utilization. CP 32.13330.2018, that specifies the requirements for wastewater disposal systems of populated areas newly built or under reconstruction; for the external networks and permanent structures for domestic, surface (rain and melt) and industrial wastewater compositionally alike, considers the requirements of the federal legislation not to the fullest extent. Based on the analysis of the relevant federal laws and provisions of CP 32.13330.2018, the need to establish basic requirements for sewer pipelines is substantiated, i. e. pressurization, steady-state stability, estimated transported wastewater flow pass and maintainability.

Key words

leak-proofness , sewerage , water disposal , repairability , steady-state stability , integrity

The complexity of the reliability index of water and wastewater facilities
(to be discussed)

Summary

Reliability has been the most important feature of water and wastewater facilities. However no clear consistent definition of this notion and the procedure of calculating its indicators have been formulated so far. At present it can be done only with use the mathematical tool of the reliability theory. Most of the published editions on that subject offer one of the failure-free performance parameters as a reliability index without considering the fact that water and wastewater facilities are maintainable. Hereof it follows the need of using the integrated reliability index that takes into account both failure-free performance and maintainability. For the calculation of this index Markov model with continuous-time discrete state is used.

Key words

repairability , water and wastewater systems , Markov model , failure-free performance , integrated reliability index , simple index

The Use of Up-To-Date Pipeline Valves at Object of Municipal Enterprise Samaravodokanal

Summary

ME Samaravodokanal is one of the largest enterprises of the city, provides the population, industrial and heat and power engineering objects of the city of Samara with water supply and wastewater disposal services. The enterprise operates four complexes of pumping-filter stations of total output over 1 mil. m3/day, city treatment facilities of 1 mln. m3/day output, 182 relift pumping stations, and also1533,2 km of water supply and 1209,4 km of sewerage networks. The experience in the use of up-to-date pipeline valves at objects of ME Samaravodokanal is presented. General principles of the selection of a valve type depending on the place of application are formulated. The economic efficiency and technical advantages of adoption of up-to-date stop valves are shown.

Key words

reliability , valves , gate , rotary-butterfly valve , repairability