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