INTRODUCTION TO PIPING AND PIPE LINES.pptx

It will help you for studying about piping and pipe lines

1. INTRODUCTION TO PIPING AND PIPE LINES

2. PIPES It is a Tubular item made of metal, plastic, glass etc. meant for conveying Liquid, Gas or any thing that flows. It is a very important component for any industrial plant. And it’s engineering plays a major part in overall engineering of a Plant. Two types of pipes are : Seamed or Welded Pipes and Seamless Pipe. Seamless pipes are wrought tubular product made without a welded seam by drawing or extrusion process. Welded pipes are manufactured by EFW (Electric fusion welding) or ERW (electric resistance welding) Process. The longitudinal seam is welded by manual or automatic electric arc process.

3. SEAMLESS PIPES Seamless pipe is formed by piercing a solid, near-molten, steel rod, called a billet, with a mandrel to produce a pipe that has no seams or joints.

4. BUTT WELDED PIPE Butt-welded pipe is formed by feeding hot steel plate through shapers that will roll it into a hollow circular shape. Forcibly squeezing the two ends of the plate will together produce fused joint or seam.

5. SPIRAL WELDED PIPE Spiral-welded pipe is formed by twisting strips of metal into a spiral shape, then welding where the edges join one another to form a seam. This type of pipe is restricted to piping system using low pressure due to its thin wall.

6. NOMINAL BORE The nominal bore of a pipe is its internal diameter. The nominal bore determines how much volume you have in the pipe to transport your particular substance. NOMINAL PIPE SIZE (NPS) NPS is a North American set of standard sizes for pipes used for high or low pressure and temperature. Pipe size is specified with two non-dimensional numbers: NPS for diameter based on inches and a schedule for wall thickness. For NPS 1/8 to 12, NPS is equal to Inside diameter in inches and for NPS 14 & above NPS is equal to outside diameter.

7. SCHEDULE NUMBER Pipes are designated by schedule number. Schedule number is represented by the pressure carrying capacity of the pipe. 1000 x P (Internal pressure) Sch .No = S(Allowable tensile strength of material) Irrespective of pipe diameter, equal schedules have equal pressure carrying capacity. For stainless steels schedule number are designated by suffix S i.e. 5S, 10S, 40S, 80S etc. XS means extra strong, XXS means double extra strong.

8. PIPE WALL THICKNESS Calculation of pipe wall thickness is based on thin cylinder formula which states that required thickness “t” for internal pressure “P” and outside diameter “D” is given by: (for seamless pipes) t = PD 2S Where S = safe stress value in Kg/cm2 D & t in cm P in Kg/cm2

9. If we consider welded pipes with weld efficiency value “E”, then t = PD 2SE E is generally expressed in decimal fraction or percentage, E = 0.8 or 80% Pipes are always given tolerance on thickness. Standard thickness tolerance for manufacturing ( also called as mill tolerance ) is + or – 12.5% of minimum required thickness. Also for corrosive medium, pipes are given certain corrosion allowance “C” expressed in mm. Additionally sometimes extra allowance (a) is required to take care of thickness reduction due to threading or grooving.

10. Thus, 0.875 X T = t + C + a T is actual nominal thickness

11. CLASSIFICATION BASED ON END USE LINE PIPE It is mainly used for conveying fluids over long distances and are subjected to fluid pressure. It is usually not subjected to high temperature PRESSURE PIPE These are subjected to fluid pressure and temperature. Fluid pressure in generally internal pressure or may be external pressure (eg. jacketed piping ) and are mainly used as plant piping. STRUCTURAL PIPE These are not used for conveying fluids and not subjected to fluid pressures or temperature. They are used as structural components (eg . handrails, columns, sleeves etc.) and are subjected to static loads only.

12. DIFFERENCE BETWEEN PIPE AND TUBE Pipe is identified by Nominal bore and thickness is defined by schedule. Tube is identified by Outside diameter and thickness is defined by Birmingham's wire gauge.

13. PIPING Piping is defined as large series and networks of pipe within the well defined boundaries of the plant/plot with all fittings and equipments like pump, valves and other miscellaneous items with an intention to transfer fluid from one facility to another with in those boundaries as required. “Piping systems are like arteries and veins. They carry the lifeblood of modern civilization.”

14. Two types of piping are: UNDERGROUND PIPING Underground piping are routed underground or buried underground. U/G, Buried piping should be properly protected from corrosion. Pipe may be properly wrapped and coated to prevent corrosion Or U/G piping be protected by using Cathodic protection. Mainly coal tar tapes are used for wrapping. ABOVEGROUND PIPING Aboveground piping are pipelines above the ground level. Pipes are protected from corrosion by painting. Before painting pipes should be properly blasted to make surface rough.

15. PIPELINES Pipelines are defined as long series of pipes usually of large diameter often underground with few fittings and equipments mostly pumps and valves (mainly to control the flow, that are laid with an intention to transport any fluid (liquid or gas) over long distances. Pipeline engineering deals with transport of hydrocarbons with huge capacity through long distances.

16. PIPING APPLICATIONS OIL AND GAS SECTOR CHEMICAL PLANTS PAPER AND TEXTILE PHARMACEUTICALS FOOD AND BEVERAGE COMMERCIAL PURPOSE

17. EXPECTATIONS FROM PIPING ENGINEER Wide engineering knowledge Awareness of standards, codes and practices Methods of pipe fabrications and erection Knowledge about equipments used Knowledge about design and layouts

18. BLOCK DIAGRAM OF PIPING ENGINEERING PROCESS FLOW DIAGRAM EQUIPMENT LAYOUT PIPING GENERAL ARRANGEMENT MATERIAL TAKE OFF PURCHASE SPECIFICATION PIPE SUPPORT GAD PIPE SUPPORT INSTALLATION ISOMETRIC DRAWINGS FABRICATION DRAWINGS FABRICATION DRAWINGS PIPING & INSTRUMENTATION DIAGRAM

19. LIFE CYCLE OF PROCESS PLANT TECHNO ECONOMIC FEASIBILITY DESIGN PHASE CONSTRUCTION PHASE COMMISSIONING PHASE OPERATION/PRODUCTION PHASE

20. INSULATION INSULATION - Insulations are done to prevent heat transfer. When hot fluid flows through pipe then generally pipe is insulated. There are two primary reasons for insulating the pipe carrying hot fluid. Containing the heat inside the pipe. Insulation preserves the heat of the fluid. It is called Hot Insulation . Personnel safety, so that people do not get burn injury by touching hot surface of pipe. It is called Personnel Protection Insulation .

21. Cold pipes are also insulated. Cold or chilled fluid carrying pipes are insulated to prevent heating of cold fluid from outside. It is called Cold Insulation . Some times cold pipes are insulated to prevent condensation of atmospheric water vapour on pipe surface. It is called Anti-Sweat Insulation . Other types of Insulation When gas flows through pipes at high velocity, it creates noise. In such cases pipes are insulated to reduce noise. It is called Acoustic Insulation . Some times pipe and it’s content are heated from outside, by heat tracing element. In that case pipe along with heat tracing element are insulated to conserve the heat of the tracer. It is called Heat Tracing Insulation .

22. INSULATION MATERIAL - The insulating material should be bad conductor of heat. There are two basic categories 1) Fibrous Material , which has large voids full of air between fibers - Cork, Glass Wool, Mineral Wool, Organic Fibers. Note stagnant air is a bad conductor. 2) Cellular Material , which has closed void cells full of air - Calcium Silicate, Cellular Glass (Foam Glass), Polyurethane Foam (PUF), Polystyrene (Thermocol), etc. Some times Cast material like Cement Plaster or Plaster of Paris are also used. INSULATION CLADDING - Insulation materials are generally soft or fragile. So the outer surface of insulation are protected with Aluminum sheet or GI sheet cladding.

23. TYPES OF FLOW STEADY OR UNSTEADY FLOW In steady fluid flow, the velocity of the fluid is constant at any point. When the flow is unsteady, the fluid’s velocity can differ between any two points. Steady-state flow refers to the condition where the fluid properties at a point in the system do not change over time. Otherwise, flow is called unsteady.

24. VISCOUS OR NON-VISCOUS FLOW Viscosity is actually a measure of friction in the fluid. When a fluid flows, the layers of fluid rub against one another, and in very viscous fluids, the friction is so great that the layers of flow pull against one other and hamper that flow . Viscosity usually varies with temperature, because when the molecules of a fluid are moving faster (when the fluid is warmer), the molecules can more easily slide over each other.

25. COMPRESSIBLE OR INCOMPRESSIBLE FLOW Fluid flow can be compressible or incompressible, depending on whether you can easily compress the fluid. Liquids are usually nearly impossible to compress, whereas gases are very compressible. All fluids are compressible to some extent, that is, changes in pressure or temperature will result in changes in density. However, in many situations the changes in pressure and temperature are sufficiently small that the changes in density are negligible. In this case the flow can be modelled as an incompressible flow.

26. LAMINAR AND TURBULENT FLOWS Laminar flow is fluid motion in which all the particles in the fluid are moving in a straight line. Where the fluid moves slowly in layers in a pipe, without much mixing among the layers. Typically occurs when the velocity is low or the fluid is very viscous. Turbulent flow is an irregular flow of particles; characterized by whirlpool-like regions. Opposite of laminar, where considerable mixing occurs, velocities are high. Laminar and Turbulent flows can be characterized by using Reynolds Number. NR < 2000 – laminar flow ,NR > 4000 – Turbulent flow. For 2000 < NR < 4000 – transition region or critical region - flow can either be laminar of turbulent

27. NR = V D ρ = V D ή ν Where NR – Reynolds number V – velocity of flow (m/s) D – diameter of pipe (m) ρ – density of water (kg/m3) ή – dynamic viscosity (kg/m . s) ν – kinematic viscosity (m2/s)