Universal working mechanisms of hydraulic machines
for trenchless pipeline rehabilitation

Summary

The advanced technology of trenchless rehabilitation of old pipelines with the use of hydraulic machines with the working mechanism that includes a cutter block with disk blades and a conical expansion tool is considered. Shockless pipe destruction provides for reducing significantly the risk of soil sloughing and damage of the adjacently laid underground utilities. The analysis of similar working mechanisms of the hydraulic machines for trenchless pipe renovation (Grundoburst Tracto-Technik, Germany, and Hydro Burst Vermeer, USA) revealed a number of drawbacks consisting in the limited application area and low level of versatility of these working mechanisms that did not provide for pulling through a new plastic pipe of extended length; repairing pipelines with bends and turns; renovating pipelines of wide diameter range with the use of a single equipment set. Three prototypes of the working mechanism based on hydraulic machines were manufactured and tested. The first prototype provides for pulling through a new plastic pipe that is 1.5–2 times longer (to 200 meters and more). The second is designed for the renovation of pipelines with up to 45 degrees bend angle. Adding joint assembly links allow increasing the bend angle (to 70 degrees). The third prototype is designed for renovating pipelines of various diameters (fracture from 150 to 200 mm) with the use of a single set. This design makes the given technology more simple and cheap. The suggested designs of the universal working mechanisms based on hydraulic machines provide for trenchless pipeline rehabilitation under various operating conditions.

Key words

pipeline , trenchless repair , hydraulic machine , working mechanism , pulling part

Temperature and pressure monitoring system of the water distribution networks of Yakutsk

Summary

The information on the design of the system of monitoring temperature and pressure in the water distribution networks of Yakutsk is presented. In operating the municipal water supply under low temperature conditions continuous water temperature and pressure monitoring in the network is needed to prevent from pipeline freezing and overheating of the pumped water. To this end automated systems of temperature and pressure monitoring in the networks have been developed. To provide for the data remote transfer for the system control Circuit Switched Data (CSD) technology for GSM mobile networks is used. With the help of this technology two GSM modems can establish a communication channel for import of data. For the operation of this system at a remote measuring point a cellular communication signal of the selected operator at the facilities together with continuous power supply shall be available. AIR-10N pressure sensors and TSPU-205-N temperature sensors were used as transmitters with 4–20 mA standardized signal; CPU – computer-process interface modules manufactured by Elemer SPE OJSC were used for subsequent transformation of signal and interface. Exchange of data between the computer and analogue input modules is ensured by MODBUS protocol version. To provide for the system control an information computerized system including a data base with Microsoft SQL Server 2008 Express, a service of terminal polling with the help of Windows service application, and an operator interface was developed. At present the system is operating steadily in the mode of systematic polling. The designed system can provide for collecting data from 200–300 measuring points.

Key words

water supply , monitoring , pressure , pipeline , centralization of control , temperature