CCTV inspection of pipelines has been extensively used in Russia for several decades. It became especially popular in the mid-1990s, when high quality and cost effective Russian-manufactured cameras and robots appeared on the market. Today, self-propelled, floating or pushrod pipeline CCTV systems, as well as borehole CCTV robots make up an indispensable part of the sanitary engineering equipment used in Russia's major cities. Cutters and packer systems are also employed that are largely used for local repair of pipelines.

All the product types mentioned above are available from "TARIS" a Moscow-based company specialising in development and manufacture of special robotic systems for public utility services, and oil and gas producing companies, as well as for atomic energy enterprises and other "hazardous environment" industries. The ever-growing demand for CCTV robots and trenchless local pipeline repair systems has been brought about by the effective economic characteristics of the equipment when employed in urban environment.

SEWERAGE SYSTEMS
Inspection of sewerage systems has always been one of the principal objectives of CCTV pipeline monitoring. This is due to easy accessibility of sewerage and drainage systems, as well as the importance of timely detection of flaws or damage in sewage collectors to prevent possible environmental problems. Destruction of soffit or roof of large diameter collectors has, more than once, resulted in fetid craters in residential areas of Russian cities, often running to several metres deep and many meters long.

High levels of mechanical wear, coupled with lack of the finance required for repairing sewerage collectors in Russia, necessitates the use of CCTV to detect and subsequently aid repair of these hazardous sections. Large diameter collectors, ranging from 600 mm to 3.5 m, are the most hazardous and thus, most suitable, assets to be surveyed and repaired with the aid of CCTV. It is often not possible to dam the sewer flow even for a short time, so floating CCTV systems similar to the W-400 robot are used for examining such structures. Floating modules featuring high-power lights, tilt and rotation color cameras with zoom are used in partially filled pipes along the stream to examine upper roofs of collectors susceptible to gas corrosion, pipe walls and socket joints.

The P-200 self-propelled, wheeled robot is used to inspect large diameter dry collectors. No pipe cleaning is carried out prior to the examination in most cases. Viscid sediments and oversized obstacles on the bottom of the collector set tough requirements for mobility and manoeuvring capabilities of the robot. Its powerful four-wheel drive, a set of inflatable, large diameter wheels with grousers, and spacing hubs for widening the wheel track offer significant manoeuvrability within the pipe enabling the P-200 robot to efficiently operate in sewers littered with deposited materials and solids.

Pushrod systems or P-100 robots are employed to inspect sewer pipes with small diameters ranging from 100 to 400 mm.

OPERATIONS
Scheduled CCTV surveying of sewerage and drainage facilities is carried out to detect destruction areas of soffits of large diameter collectors, which then undergo local repairs to prevent collapse of roads and in residential areas; To detect and clear blockage sections, the principal objective being prevention of sewage effluent discharge; To detect disengaged and broken sewer pipes in order to prevent storm-water from overflowing into sewerage systems, to avoid overwhelming of treatment facilities, as well as to prevent spillage of sewage into lakes and rivers; To identify blind wells, as well as to determine sewer pipe accommodation in order to restore utility networks; To detect unauthorized taps-in; and To determine the technical status of sewer pipes, detect sections in need of urgent repair and those in satisfactory condition in order to save funds through cancelling scheduled repairs of operational sections.

A special mention should be made of CCTV systems used to clean out sewer facilities via various methods. CCTV examination of a pipeline prior to its clearing enables experts to assess the amount of work required. The results of these inspections are often used to cancel the operation altogether, once it has been found the pipe is not blocked, deformed, breached. CCTV performed in the wake of cleaning ensures guaranteed quality of the operation and it is used to facilitate acceptance and commissioning procedures so that discord and disagreement are often averted.

WATER SUPPLY LEAKAGE
Leak detectors are the principal assets used to identify leakage in water supply systems. Yet, according to data provided by the company Mosvodoprovod (Moscow Water Mains Company), accuracy of the detectors' operation can be as low as 85% in cases where the devices are employed in a large city with great water-supply facility density. If the use of leak detectors is not sufficient, the company employs CCTV systems such as the TARIS P-100 module, which is loaded into the pipe through a dismantled flap so that no welding is required. The P-100 wheeled robot is used to inspect pipes with diameters varying from 100 mm to 400 mm, over sections up to 150 m long. A colour pan and rotate camera is employed for the purpose. Pressure in the pipes is released prior to the inspection. As a result, even little holes are visible due to water trickling into the water supply system from the surrounding ground.

WORKS ACCEPTANCE
Visual examination of inner pipe walls performed in the course of acceptance procedures is growing ever popular in Russia. The trend has been brought about through insufficient quality of pipelines and economic considerations, with the companies and enterprises operating the facilities being aware they would pay more for further repairs of faulty pipes than they would to have an inspection carried out as part of their acceptance procedures.

As far as CCTV is concerned, the most common defects include: sand sediments and foreign objects (bricks, rocks, wire left in the pipes in the course of construction). These cannot be flushed out; moreover, the objects get stuck in the system and disrupt operation of the facilities. Economic calculations performed by Mosvodokanal experts (Moscow City Water & Sewerage Authority) led them to introduce obligatory CCTV as part of any acceptance procedures. Such examinations are often carried out using P-100 or P-200 robots.

WATER WELLS
CCTV of water wells is performed in case the facilities are in need of repair, as well as after repairs, during cleaning-out and in the course of accepting a new well.

The features used to decide on repairing a well include well capacity and water quality. Among the numerous factors affecting discharge of the well and quality of the water are fissures in the upper section of the casing string causing headwater infiltration; incrustation at the level of the water-intake layer; filters clogged with clay and other sediments charged into pipes with water from fissures in the casing string; reduction in pump output; and sediment or corrosion on the walls of the well.

Depending on the defect, the well is either to be repaired or closed down. Lack of information on the flaw will lead to an error in choosing the type. of repairs, which, in turn, will result in financial loss. Thus, CCTV enables experts to cut down expenditures through taking an accurate technical decision on whether to repair or close down a well. The method can also be efficiently employed for retrieving pumps and other objects from the well. Inspection operations are performed using special deep-water video cameras. Colour video systems are produced for use in wells with diameters varying from 90 mm to 600 mm, to depths up to 300 m. A camera pan and rotate option is included. In addition to this, TARIS video systems fitted with 42 mm diameter cameras are used by certain Russian oil and gas producing enterprises inspecting assets at depths up to 3,500 m, where temperatures up to 100°C may be encountered.

RENOVATION INSPECTION
Various methods of trenchless renovation (rehabilitation) are now extensively used in Russia including: mortar (cement and sand) coating of water supply pipelines, inserting polyethylene pipes into gas pipelines, sewers and water supply facilities, laying polyethylene pipes with an impact system, and pipe bursting on a size-for-size or upsizing basis. As well as some other methods, foreign companies employ Phoenix and U-liner methods when dealing with water supply facilities and gas pipelines, whilst the Insituform technique is used in sewerage systems.

Pipeline renovation requires preliminary and final CCTV inspection whatever the method employed. Preliminary examination is carried out in order to determine the technical status of the pipe and the amount of work to be done; the final inspection is aimed at assessing quality of the rehabilitation operations performed. Visual examination provides for identifying large-diameter holes and water infiltration in pipes. Such operations must be completed prior to applying mortar coatings to the pipelines or performing lining rehabilitation. Any serious flaws are often mended before launching a rehabilitation procedure, either through digging the pipes out of the ground or through the use of packer systems to apply an internal 'bandage' to the defect area or the use of repair robots. Protruding elements such as repair pins, welding fins, lateral pipes, are located within the pipe prior to rehabilitation unless the operation being performed is pipe bursting. In cases where polyethylene pipes are to be laid using pipe bursting, the examination checks for steel insets, misalignment and other defects often encountered in cast-iron pipes, for instance.

OTHER OPERATIONS
In-pipe cutting operations are often performed to eliminate protruding elements, mainly in the course of preparation for renovation works. Equipment such as the C-200 robot is used for this purpose comprising four-wheel drive crawlers mounted with colour CCTV pan and rotate cameras and arresting devices for fixation of the system in the pipe when performing cutting works. The system boasts a three-extent cutting unit with an output less than that of most European-made systems fitted with pneumatic or hydraulic units. Despite this fact, it takes the Russian robot only marginally longer to perform any task its European counterpart can carry out. All major operations can be conducted by Russian-made systems provided the system is properly selected for every material to be dealt with.

Among the principal advantages of such an electric unit are its simplicity and low cost, operational independence and extensive technical capabilities. The system can be operated using a composite 10 mm diameter cable made up with power and signal cables; it is also capable of moving along pipes up to 300 m from the launch site (not 150 m as previously reported in the January 2003 issue of NDI). Another benefit is the small size of the system due to its small cable drum size.

Holes, fissures and other flaws are sealed with the use of packer robots. These are employed to apply bandages to inner walls of pipe at defect sections; a sleeve is made of a metal shell and a blanket of cloth saturated with a polymeric compound.

By feeding pressure through hoses the packer swells, making the metal shell adhere to the pipe wall. Placed between the metal shell and the pipe wall, the cloth with the polymeric compound seals the flaw tightly. A rubber layer can be effectively used as a sealant instead of polymeric compound provided the pressure in the pipe is low.

Sleeves made of stainless or carbon steel can also be employed. Stainless steel shells with polymeric compounds or rubber layer are more often used in the course of emergency repairs; carbon steel shells are more often used to seal large holes prior to renovation. All the repair materials have been certified for usage in water supply facilities.

CCTV EQUIPMENT
Russian operators employ robots made by several domestic and foreign companies, yet it is claimed that TARIS products make up a majority of those used in the country. TARIS launched its production of pipeline robots in 1993 with the first systems being manufactured in 1995 by request and with technical support of the Mosvodokanal enterprise. Now robotic systems are used in more than 25 Russia cities.

The current breakdown of usage for the various CCTV systems across Russia is:
TARIS 70% with the rest of the market being supplied by well known companies like Ibak, Rausch, Vretmaskin, etc.

A special mention should be made of Ibak and Rausch. Products of the Vretmaskin enterprise from Sweden are well known in the north of Russia.

The provided data is related to CCTV systems only; robotic systems used in the country for cutting and sealing works are, it is claimed, only of Russian make.

At the moment the Russian Government is realising a number of reforms aimed at harmonising the economic, political and social spheres and adjusting them to the international standards in view of forthcoming WTO's ascension, probably, in 2004. The Russian Housing - Utilities Sector has been going through a major change. The final result would eliminate state subsidies to the sector and will lead to 100% payments by the Russian population for the services provided by the local utilities enterprises. The utilities companies would become self-financing entities. They would therefore be more demanding in terms of price and quality from proposals made by contractors and bidders and eventually will require a greater scope of services. This is expected to bring about a greater competition, mainly, through tenders for the resources of the utilities companies. The bulk of the business would go in the biggest Russian cities, like Moscow and St. Petersburg, in the western part of Russia.

NO-DIG INTERNATIONAL, February 2003