FLEXIBLE, LIGHT-WEIGHT LAND DRAINAGE PIPE
By R. D. CULLUM, M.LE.D., A.R.Ae.S., M.I.A.S.
Editor of 'Engineering Materials and Design' Director of Materials Data Ltd. (London) Issued by British Information Services – The Certificated Engineer August 1965
It is increasingly difficult to define the division between engineering materials and non-engineering materials since few in the latter category are not used in some form or some condition in engineering. Fabrics, for example, suitably treated, are widely used for gaskets and flexible containers, and even for gears, bearings and other components. Similarly, products designed specifically for one field of application will often find use in an entirely different field.
One such example could be Landcoil perforated polyethene pipe, designed for land drainage, which would also appear to have possible use in rinsing tanks or for cooling and wetting applications. The pipe is robust-it is two inches in bore and 0.104 inches in thickness-but a standard coil of 660 feet weighs only approximately 168 pounds. Being coiled it is easily handled and placed in the ground either by a standard trenching machine fitted with a reel, or a mole plough of a type such that the pipe can be fed down the blade of the plough.
The design of Landcoil pipe is said to be unique. Along its length and spaced equally around its periphery are 16 rows of slots, each slot measuring approximately one-eighth inch by one-thirty-second inch on the outside and tapering to a smaller size on the inside of the pipe. A large number of small slots excludes larger soil particles from the pipe while allowing a maximum of water to enter.
Where a joint is required, a larger, unperforated, tube is available for use as a sleeve over the drain pipe. As polyethene has comparatively good low-temperature characteristics, Landcoil field pipe can be laid during the coldest of weather.
Helically Welded Tube
Tube of a different type is the helically welded stainless steel tube recently introduced to meet the growing demand for stainless tubes with thin walls and large diameters; it should also open up many new markets where a stainless tube has hitherto been impracticable. The tubes will be particularly attractive to designers encountering pipe-line problems involving corrosion, abrasion and scaling, while the fabricator will appreciate the high strength/weight ratio, ductility, and simple manipulation that is possible.
Although the largest users of this type of pipe at the moment are the paper pulp, petrochemical and food processing industries, power generation, shipbuilding, mining and building industries will likely become interested in the possibilities of the larger sizes of this type of tube.
Important characteristics of the tube are close tolerances of wall thickness and diameter and defect-free welding. The tube can be produced to almost any length and can be tested and manipulated before delivery if required.
Industrial Pneumatic Hose
Another tube of a different nature is the new industrial pneumatic hose which works on the same principle as the modern telephone cord and retracts when not in use to approximately one-twentieth of its working length. Known as Recoil, this hose is made of plastics and is available in a bright, safety-colour of orange and, being only one-seventh the weight of the ordinary hose, can be easily stored. It is abrasion and oil-resistant and can be used at operating pressures of 250 pounds per square inch.
The lightness and flexibility of this hose decrease operator fatigue and improve and facilitates the use of pneumatic tools, thereby increasing productivity. Installation is simple, only a spanner is required to fit any available British Standard Pipe and American National Pipe Thread connection. Also, quick-acting, self-sealing couplings can be fitted to permit an immediate change of the supply point or the tools used.
Cutting Fluid
Productivity is a key-word in the industry today and a new, concentrated, cutting fluid that has proved successful in machining operations is now available in an aerosol can.
The can have been introduced to provide a more precise and quicker way of applying the lubricant. Known as Lubysil BCO 14, the liquid is said to offer three main advantages-greater tool use, as it has been found that cutting tools, drills and taps do not need re-sharpening so frequently as when ordinary cutting fluids are used; reduced machining times in certain instances; and improved finish engendered by the action of silicones incorporated in the fluid. It can be used for machining any material, ranging from masonry through glass, laminates and tiles to plastics as well as all metals.
Welding Materials
Two new welding materials have recently been introduced, both claimed to be a marked advance over previous materials.
The first of these two is Incoloy welding electrode 138 which has been developed specifically for joining Incoloy alloy 800 and Incoloy alloy DS to each other or of either alloy to wrought or cast, heat-resistant stainless steel. The weld produced with this electrode is said to give outstanding high-temperature strength and resistance to oxidation, carburisation, sulphidation and thermal fatigue.
The second new welding material is a flux known as Incoflux 4, from the same company, which has been designed for use with Inconel filler metal 82. The flux wire combination can be used for weld overlay on austenitic carbon or low-alloy steels and butt welding Inconel alloy 600. Principal advantages of submerged-arc welding with the new flux and filler metal are ease of technique, the rapid rate of deposition and excellent slag removal and good weld-metal properties.
Wall Insulant
The effective insulation of walls is important, not only for homes and offices but also for factories and other buildings where constant temperature and humidity are important to a production operation. A new wall lining material known as Telstrene is a special grade of expanded polystyrene sheet with a thickness of 0.015 inches. It has a satin-like surface, is available in eleven-yard rolls, 24 inches wide; it can be applied to plaster walls with a polyvinyl alcohol type adhesive using the ordinary paper-hanging technique, It is proof against water and water vapour and is completely rotproof, and its structure of small, closed cells is said to make it an excellent thermal insulator and condensation preventer. Wallpaper can be applied to the material; alternatively, it can be decorated with emulsion paint.
Metallised Film
A new development in metallised plastics film has recently been announced. Its manufacturer claims to have successfully metallised expanded polystyrene film, the effect is a bright, sparkling, but not a mirror surface, the cellular structure of the film producing a surface which gives a 'frosted' effect. Important uses for this film include vacuum-formed containers for edibles, cosmetics and similar goods, where the material will give a measure of shock-proofing. I will not draw very deep, although it may be used for box linings and printed and embossed cards.
An interesting feature of the film is its surface texture which is soft and warm, rather like chamois leather or rose petals. Its metallised side can be tinted in a range of pastel colours.