Mechanical Seal – Technical Manual

Introduction Centrifugal pumps are used to increase pressure in a liquid for the purpose of transporting the liquid through piping and other devices for use in an industrial  process. With the higher pressure, the liquid can be transported in short or long pipelines for delivery to an ultimate destination. Examples include water pipelines, refined petroleum and crude oil pipelines. The pressure generated by the pump is gradually depleted as the liquid flows through the pipeline, due to friction in the pipe, as well as any elevation increase from the point of origin to the destination point. The liquid as it enters the pump has a certain amount of energy, due to its initial pressure (pressure energy), position (potential energy) and its velocity (kinetic energy). The potential energy depends on the location of the liquid from some datum, such as sea level. The kinetic energy is due to the motion of the liquid. The sum of three components is the total energy of the liquid. As the liquid comes out of the pump, energy is imparted by the rotating element (impeller) in the pump and the liquid pressure increases. The velocity of the liquid also changes from that at the pump inlet. In a centrifugal pump, the liquid is accelerated by centrifugal force during its passage through the rotating pump impeller and, finally at the exit, the kinetic energy is converted to pressure energy as it exits the pump volute into the discharge piping.

Reciprocating Compressors Construction Details In general, materials for the construction of the compressor and auxiliaries are normally the manufacturer's standard for the specified operating conditions except as required by the datasheet or certain specifications.

The most numerous types of fluid machineries are of the pump family (machines which add energy to the fluid), other important types are turbines (which extract energy from fluid). Both types are usually connected to a rotating shaft, hence also called turbomachineries. The prefix turbo- is a Latin word meaning ―spin’’ or ―whirl,’’ appropriate for rotating devices. The pump is the oldest fluid-energy-transfer device known. At least two designs date before Christ: (i) the undershot-bucket waterwheels, or norias, used in Asia and Africa (1000 B.C.) and (ii) Archimedes’ screw pump (250 B.C.), still being manufactured today to handle solid-liquid mixtures or to raise water from the hold of a ship. Paddlewheel turbines were used by the Romans in 70 B.C., and Babylonian windmills date back to 700 B.C. Since that time, many variations and applications of pumps have been developed. The power generating turbomachines (turbines) decrease the head or energy level of the working fluids passing through them and they are coupled to machines, such as electric generators, pumps, compressors etc.

INTRODUCTION : 1.1 Why water treatment? Pure water [H2O] is a colourless, odourless and tasteless liquid. It plays a huge part in everyday life: 70% of the earth’s surface is covered by water in the form of oceans, and the rest of the planet has large quantities of water in the form of lakes, rivers and watercourses, ice and snow, and humidity, as well as the principal element of animal life (>50%) and plants (approx. 80%). When we talk about water in general, we usually mean water for some specific purpose, e.g. drinking water or process water for industry. This is where the term water treatment comes into the picture, as the available water resources or that provided by nature is not always of a suitable quality for immediate use for the specific purpose. Drinking water must be pure, and should preferably taste good too, and it must not contain substances that could cause problemswith daily use. Process water, which is water that forms a direct and important part of a process or product in industry, must have a chemical composition and temperature that is precisely suited to the specific requirements.