With the advent of the PVC pipes which are fundamentally Poly Vinyl Chloride pipes the use of it in the bore casing in borehole has increased worldwide. The usage of steel has few problems associated with it in which foremost are the weight and flow characteristics. The steel bore casing in comparison to PVC pipes gives less volumetric efficiency. Bore casing pipes needed few troubleshoot things at its best like corrosion resistance and galvanic corrosion which are provided with 100% excellence by the PVC pipes. Steel pipes whenever comes I contact with water and mud after a period of time becomes vulnerable to galvanic corrosion. Some of the other features of the PVC pipes which makes it better for bore casings are that it does not require any external coating for protection which reduces the cost and maintenance but which was needed in case of the steel pipes. The PVC are totally unaffected by the acids and alkali which does attacks the bore casing but in case of the steel it needs further coating to prevent material damage. The steel pipes are not only heavy, but installation problems were pre dominant in this case, but the PVC pipes are much more lighter and far easy to install mostly at bends the effectiveness of the PVC can be easily observed. The steel pipes water transport in bore casing are no doubt safe but in case in the long run acidic corrosion, takes place it demands complete removal but not in case of the PVC pipes which provides complete safe water transportation. The flow characteristics as per the survey and research it has shown that PVC pipes in bore casings provide 45% better flow (friction less) than the steel pipes used for the same purpose. In the newest advent of the PVC pipes, the temperature consideration is one of the prime aspects as these PVC works best in a wider range of temperature than the steel pipes. The modern domestic usage of the PVC pipes for the bore casing at bore holes has increased up to 67% worldwide in the new installation. The long run maintenance free work of the PVC pipes than the steel has been the most prominent aspect of the PVC pipes installation in the bore casings of the borehole. In several cases, the bacterial growth in the steel pipes of the bore casing has been evident which in terms lead to erosion and corrosion of the material, but with PVC pipes this problem does not exist at all as the polymer does not support bacterial growth at all in any place. The three basic things which are kinetic movement, polarization effect and the chemical reaction which may occur in case of steel pipes does not take place in PVC pipes for the bore casings at all. The algae growth does not occur in case of PVC pipes, which enhances its life to three fold than in comparison to steel pipes. Indeed the usage of the PVC has proved to be one of the best alternatives of the steel pipes for the bore casing of the bore hole in terms of price, maintenance, installation and long life of the piping.
The PVC pipes which are essentially Poly Vinyl Chloride. It is the latest advent as a replacement of the metal pipes that was in use for last several centuries. The PVC is in some cases, not inert whereas HDPE pipes are commonly used for their inert characteristics and they are highly corrosion resistant. No taking in terms of the material of production the PVC pipes are made of Poly Vinyl Chloride out of which plasticizers are added to it to make it much more flexible and soft. The production of HDPE pipes, which are High Density Polyethylene pipes which are high in strength in comparison to its density. The highest strength plastic pipes available are the HDPE pipes. Now coming to the application of these two pipes the PVC pipes has got more application areas than the HDPE pipes like PVC pipes are used for water distribution and sewage pipelines. The usage of the PVC pipes is also in the field of irrigation across the world for its excellent corrosion resistant characteristics. The sanitary usage of the PVC is also quite high ad has proved to be highly productive one. The HDPE pipes are chemically inert and that it is why in safe and edible oil or in such consumable fluid distribution the usage of HDPE has been found. Due its light weight and high strength in extended distribution system where PVC may prove to be insecure the HDPE pipes play a good role. The abrasion and chemical resistance of the HDPE pipes has been used in the transfer chemical products also, in the market. In some cases even though the cost of the HDPE is greater the smooth flow characteristics of these pipes is more than the common PVC pipes found in the market. HDPE pipes are considered more durable and in terms 60% more safer than the PVC pipes usage in the market. Now coming to the cost factor, obviously HDPE is much more expensive than conventional PVC available in the market and this feature has lead to reduction of the usage of the HDPE pipes on a large scale. In last 7 to 8 years, the usage of the HDPE pipes has been in the field of the telecom industry also. The plasticizers those, which are found in PVC are not found in HDPE which makes up a little difficulty in giving flexibility to the product. The insulation characteristics of PVC pipes are less than the HDPE pipes, and this has been utilized in various core industries. Even though the usage of the PVC pipes is still much more than the HDPE pipes around the world due to the cost factor as well as the lack of flexibility that the HDPE pipes do have than the PVC pipes. The shift from PVC to HDPE has been reported in the sewage line systems by various municipal corporations around the world which is showing a new dimension in the piping market.
A problem with using poly pipe for borecasing is that due to its molecular weight if the bore has a very high static water level then the poly casing will float and come up out of the ground, this is why upvc pipe is used for casing in water bores, it is heavier than water and will sink.
In environmental bores, if the bore is to look for hydrocarbons, such as fuels and oils the HDPE would be used as pvc would be eaten away.
HDPE is used as an alternative material for PVC bore casing in monitoring wells, it is not usually used as bore casing due to its molecular weight, as it is lighter than water it will float and has been found to pop out of the bore into the air on deeper bores. Its chemical resistance is what makes it interesting and capable of being used in monitoring wells, especially where Hydrocarbons are in the water solution. Hydro carbons will eat PVC very quickly so the monitoring bore will collapse and a new bore drilled making this an expensive operation.
By using HDPE in this situation is the ideal solution being fairly inert to the hydro carbon solutions, the HDPE casing must be grouted or cemented in place so the pipe will not float out of the hole.
1: No extra costs.
2: Longer life less replacement holes.
3: Tougher material cannot break easily.
4: Readily available material.
5: Sizes available to suit your exact requirements’.
6: Light weight yet still strong.
7: Highly Chemical resistant.
I was asked by a consultant yesterday how far could the put 250mm pvc , typical engineers, what tensile strength, has it been done before, collapse pressure and the std one
Does it meet As1477?
The answer is no to the AS1477 question, as soon as we cut, slot, thread or change the pipe in any form then it cannot meet As1477 standard.
As a qualified driller with many years of experience under your belt, you know what works and what doesn’t. You don’t need a bunch of technical information that can be hard to understand. Continue reading
We have a call from Drillers World in New South Wales asking if we could slot 100 & 65 class 18 UPVC pipe to a specification that meets the specification for the RTA, this calls for the slotting and supplying of Upvc pipe to meet RTA D&C R40 specification. The design pattern of slotting the pipe calls for a slot that is 1/3 of the pipes circumference; this is impractical due to the diameter of the blades needed to perform this slotting operation.
What we decided to do so the pipe could be slotted efficiently was to submit a different pattern that would produce the same open area and not make any difference to the performance needed on site. The benefits of changing the slot pattern is the job could be produced more efficiently lowering the costs, we could meet the deadline needed and the pipe had a considerable stronger support weight. Continue reading