From tees to tap connectors, the Tectite classic range includes all the fittings you need to install a high-quality domestic system, and BES can supply all you need. The right pipes and tubes for any job Tectite Tube offers installers the flexible installation of plastic with none of the compromise, suitable for use on central heating and potable water

We can help you acquire what you need to minimize interfacing time and improve logistics. We select the correct combination of materials by taking into consideration the specified service conditions, including chemical composition of the conveyed fluid, pressure, temperature, water depth, and a range of other factors that affect the flexible pipe design. EN 14800: Corrugated safety metal hose assemblies for the connection of domestic appliances using gaseous fuelsSun Jingjing, Liu Peilin, Duan Menglan, Zhang Jiuju, Hu Xianwei, Guijin (2011) Development status and trend of deep-water umbilical cord cable installation technology [J]. Petroleum Mine Machinery, 2011 ISO 10807: Corrugated flexible metallic hose assemblies for the protection of electrical cables in explosive atmospheres The brand new and completely unique Tectite Metal Push-fit System, offers the UK installer the next evolution in domestic plumbing. We believe in the efficiency and swift installation offered by a flexible plumbing solution, combined with the performance and reliability offered by the traditional metal systems Pegler Yorkshire is renowned for. Marston’s observations of load on buried pipe were validated in a 21-year study, from 1927 to 1948, where concrete, cast iron (both rigid pipes) and corrugated steel pipes (flexible pipe) were buried under an embankment of 15 ft. Measured loads on the pipes were compared with loads calculated by the Marston theory of loads on underground conduits, and were found to closely agree. Figure 4 presents measured loads on the concrete and corrugated steel pipe. It can be seen that the load on the concrete pipe was consistently 50 percent greater than that on the corrugated steel pipe of approximately the same diameter. Buried pipe design, then, was inextricably connected to the development of highway systems in the United States. Marston was the first Chairman of the federal Highway Research Board. Our knowledge of pipe-soil interaction, as well as the development of new pipe materials and the improvement of traditional ones, has grown by leaps and bounds since those early days, leading to a multi-billion dollar global pipe materials industry. Another relatively new construction method in buried pipeline construction and rehabilitation is the advent of trenchless technology.

Feret JJ, Bournazei CL (1987) Calculation of stresses and slips in structural layers of Unbonded flexible pipes. J Offshore Mech Arctic Eng 109(3):263–269 In his analysis of external loads on buried pipe, Marston defined two main types of loading conditions of buried pipes, a ditch conduit (referred to as trench load condition in present day nomenclature), and a projecting conduit (referred to as an embankment condition in present day literature), Table 1. Equation 2 for rigid pipes indicates that the load on buried pipe is directly related to the trench width, i.e. the wider the trench, the higher the load. This relationship between trench width and load is applicable and equation 2 for trench condition can be used for all trench widths below that which gives a load equal to the load indicated by equation 4 for a positive embankment condition. The width at which the load equality for the two equations develops is referred to as the transition width. The embankment equation (4) must be used for rigid pipes beyond the transition width. Corroboration of Marston Load

Marston Load Calculations in Trench Condition

Antiwear layer– Nonmetallic layers are incorporated to prevent wear and tear between the structural elements. Manufactured by Pegler with an integrated aluminium layer which allows the pipe to retain its shape when bent, our Tectite metal pipe coils come in lengths of 25 m, 50 m and 400 m.

The hose should not be subjected to twisting; Also, the installation should be such that flexing takes place only in the plane of bending.The range of stainless steel braided hose provided by Proflex Hose are made to be amazingly durable and great in strength. With this form of hose, an external layer of braid is added to prevent the elongating of a tube when pressure is applied. This enables better flexibility and movement for the hose. A full selection of fittings and finishes are available from Proflex Hose, including flanges, screw ends, hydraulic hose fittings and other fittings to fit your requirements. For positive projecting conduits, Marston also determined, initially purely through mathematical reasoning, the existence of a horizontal plane above the pipe where shearing forces would be zero, referred to as the plane of equal settlement. Settlement of interior and exterior prisms above this plane is equal. Marston Load Calculations in Trench Condition Chen BH (2005) Experimental study on mechanical properties of oil hose. Master’s thesis, Tongji University The basic concept of the Marston Load Theory is that the load on a buried pipe, because of the weight of the column of soil, or central prism, directly above the pipe, is modified by the response of the pipe and the relative movement of the side columns of soil, or external prisms (adjacent to the pipe, between the pipe and the trench walls on either side), to the central prism. The relative movement of the central prism and the side prisms result in shearing stresses or frictional forces, calculated using Rankine’s theory.

The vertical load at the top of the bore within the width of the excavation is the upward friction forces and the soil cohesion along the limits of the soil prism directly above the bore subtracted from the weight of the prism above the bore. The 2cCtBt in Equation 6 represents the cohesion of undisturbed soils. Marston recognized that in a trench (generally, trench width = 2 x pipe diameter), when the side columns of soil or the external prisms are more compressible than the pipe due to its inherent rigidity, this causes the pipe to assume load generated across the width of the trench. The shearing stresses or friction forces that develop due to the differential settlement of the external prisms and the central prism are additive to the load of the central prism alone. Pipes that behave in this manner are referred to as Rigid Pipes. Generally, rigid pipes start showing signs of structural distress before being vertically deflected 2 percent. Rigid pipes include reinforced non-cylinder concrete, reinforced concrete cylinder, prestressed concrete cylinder, vitrified clay, polymer concrete, cast iron, asbestos cement and cast-in-place pipes. Flexible Pipe Hong Guo, Yan Qu, Qingzhen Lu, Jun Yan, Qianjin Yue (2011) Structure design of umbilical for deep water subsea production system. In: Proceedings of the 15th China ocean (shore) engineering symposium. Jun 2011 Sharp bends should be avoided while installing flexible hoses. The Technical Data Section of the vendor catalog should be followed to maintain the minimum centerline bend radius for intermittent flexing.As the corrugated interior tube is seamless, stainless steel conduit is ideal for use with liquids or gasses under pressure, especially when fitted with external braiding. With first-rate corrosion resistance, a stainless steel flexible conduit is also ideal for use in chemically demanding situations – and this combination of factors makes them absolutely perfect for use in the petrochemical industry, or in steelmaking, chemical smelting, the automotive industry the power generation industry and dozens more. Tensile armor– A number of structural layers consisting of helically wound flat metallic wires. The layers are counter-wound in pairs. The tensile armor layers provide resistance to axial tension loads. Our 3m long Tectite flexible metal straight pipes are manufactured from PE-x with an Aluminium Layer and come in various diameters, such as 15 mm and 22 mm. Why choose multi layer pipes? Outer sheath– An extruded polymer layer that shields the pipe's structural elements from the outer environment and gives mechanical protection. For pressure hoses with braided reinforcement, the corrugation stress comes mainly from the bending of the hose. Therefore, the corrugation stresses can be controlled by setting a limitation on the bending. In other words, the installation is acceptable if the hose is not bent beyond the limiting radius. Similar to the situation discussed in the bellow expansion joint, the mode of failure of the hose corrugation is due to fatigue. Therefore, the bend radius limitation depends also on the number of operating cycles expected. Most manufacturers provide two limiting radii, one for static applications involving a one-time fit-up installation, and the other for operational movement involving many cycles of intermittent flexing. The whole design and installation process actually ensures that this minimum radius is maintained during the initial layout and throughout the operation. Factors for Metallic Flexible Hose Selection