:::FLANGES:::

          After welding, flange is the second most commonly utilized joining technique. Flanges are utilized when the joints are needed dismantling. It provides easy access for maintenance like cleaning, inspection and modifications. Flange connects the pipe with numerous equipment, pumps and valves to form piping. Breakup flanges are added in the pipeline system if regular maintenance is needed or necessary during plant operation.

          A flanged joint consists of three distinct and independent although interrelated segments; the flanges, the gaskets, and also the bolting; that are assembled by yet another influence, the fitter. Sometimes flanges are welded to the pipe lines too. Exceptional controls are needed in the selection and application of all these components to accomplish a joint. A gasket is placed between the two mating flanges which provide acceptable leak tightness.
          However, it is not recommended to used flanged connection in underground piping when it is yo be buried. There are a variety of flanges are available. Flanges are classified as following below:
          1. On the basis of type of connection
          2. Based on flange facing type
          3. Material type
          4. On the basis of Temperature and pressure Ratings

AIR KNOCKER

          Air knocker is a kind of process automation equipment, designed to eliminate problems occurring due to the deposition of powder inside a hopper. This equipment consists of a "Magnetic Piston". Due to the interaction between Magnetic Piston and Air pressure this equipment dislodges some force on hopper. 

AIR KNOCKER

TYPES OF FLANGES

Flanges can be classified in different ways as follows:

1. Based on Type of Connection:

a) Threaded Flanges:

         These types of flanges also called as "Screwed flanges", because these flanges having a thread inside the flange bore. The thread inside the flange bore which fits on the pipe which is having a matching male thread on the pipe. The main advantage of this flanges is that they can be attached to the pipe without any welding. In some cases a seal weld is also used in combination with a threaded connection. This type of joint connection and dismantling is speedy and also simple but for high pressure and temperature applications these are not suitable. It is also not suitable for a pipe system with thin wall thickness because thread cutting on a pipe of thin wall thickness is not possible so we have to choose pipe with thicker wall thickness.

b) Socket-weld Flanges:

          Socket-Weld Flanges features a female socket in which pipe is fitted. Generally Socket-weld flanges are used for small size (NPS 2 and smaller) and high pressure piping systems. These flanges static strength is equal to slip on flanges.

          The connection is done by inserting pipe into the recess area and 1 fillet weld is done from outside on the pipe. Before creating the welding, we need to create some space between the flange and pipe.

          To reduce the residual stress at the root of the weld that could occur during solidification of weld metal bottom clearance is given in the socket weld. In the bottom image X measures the expansion gap. 

Disadvantages: 

1. Maintain specific gap.

2. Cracking problems between the flange and pipe by corrosive  products can cause problems.

c) Slip on Flanges:

SPILLWAY

          A spillway is a hydraulic structure built at a dam site for the controlled release of the surplus (or) excess water from Reservoir (or) Levee into a downstream area after it has been filled to its maximum capacity. In the United Kingdom, these are called as "Overflow Channels". Spillways ensure that the water doesn't overflow and damage (or) destroy the dam.

          Every reservoir encompasses a certain capacity to store water. If the reservoir is full and flood water enters it, the reservoir level will go up and may eventually result in over-topping of the dam. To prevent this situation, the flood has to be passed on to the downstream and this is done by providing a spillway which draws water from the top of the reservoir. A spillway are often a part of the dam or separate from it.

          Spillways can be controlled (or) uncontrolled. A controlled spillway is furnished (provided) with gates which can be raised (or) lowered. Controlled spillways have certain advantages. When a reservoir is full, its water level will be equal to the crest level of the spillway.

          If flood enters the reservoir at that point, the water level will start going up and simultaneously water will start flowing out through the spillway. After flood stops, the reservoir level will come down and eventually come back to the normal reservoir level.

          Spillways are classified into different types on the basis of the arrangement of the control structure, a conveyance channel and a terminal structure. Within the next article, we will discuss in brief all the different types of spillways with pictures.

Credits: QUORA

Fan Pump or Split-Case Pumps | | Use of Fan Pump in Paper Making Plant | |

What is a horizontal split case pump?

          "Horizontal split case pump is a type of centrifugal pump, within which the casing is divided into two separate chambers". It is completely different from an End suction pump (or) Inline pump. Within the End suction pump casing, the suction nozzle, and also the discharge nozzle are all enclosed in a single chamber.

Image Courtesy: Https://www.pattersonpumps.com

          Based on design the split casing pumps are divided into two major types. When the casing is split along a vertical plane, in regard (reference) to the impeller, it is stated as a vertical split case pump; When it is split on horizontal plane, it is stated as horizontal split case pump. This kind of casing style is a lot of economical for higher flow applications, and also the impeller can be supported by bearings on both sides, an advantage for large, high flow pumps.

          The pump has the suction and discharge connections in the lower half of the casing, opposite to one another. The impeller is mounted on a shaft which is supported by bearings on each side.

          Split casing pumps are more costly than End-suction or Inline pumps and also not flexible and not adaptable as vertical turbines. However they are most durable, efficiency and dependability.

          A properly designed, installed, and operated split case pump can provide decades of life.

Axially- split horizontally- mounted pump Advantages:

          The most common split case pump is axially split (-- meaning the flange at which the pump casing separates in the same plane as the pump axis), a single- stage, between bearing, non-self priming centrifugal volute pump. The design of the pump allows for easy removal of the pump's top casing to enable easy and quick access to the pump's components without interfering with the motor or the piping system.

          Radially split casing pumps are also available in market; they are useful in very high pressure and high temperature industrial applications (Boiler- feed pumps are a common use for radially-split pumps).

          In some sort of designs, the independent bearing casing permits for easy maintenance without the requirement for removing pump's top casing. The pump's double volute design minimizes the radial load on the shaft, increasing parts life and reducing vibrations to provide quite operation.

          The split case pump is available on the market in numerous designs and also made from diverse materials to suit a wide range of applications. The main parts in the pump such as, impeller, casing, wear rings and shaft can be available in various materials to suite the fluid that is being pumped and the environmental conditions.

          The pump also comes in a variety of configurations and designs including horizontal, vertical open shaft and close coupled configurations; with counter clockwise or clockwise rotation design options.

Balanced Design:

Between-the-bearings: These pumps are also called as "Between-the-bearing" pumps. Because the impeller on the shaft is supported by bearings on both sides.

Double- suction impeller: A double suction impeller imposes fewer loads on the bearings when compared to the impeller that only draws in water from one side of the impeller (single-suction type).

Applications:

         Split case pumps are by design, a more balanced machine than the most other types of pumps. The versatile design of the split case pump, robust bearings and a maintenance friendly casing design makes it suitable for a wide range of domestic, municipal water, industrial (Paper, oil & gas plants) and other commercial applications. Multi-stage split case pumps provide economical, reliable high-head pumping for uses like booster service and boiler feed. Other applications include irrigation, public water supply, process cooling, public waterworks cooling systems, and HVAC.

Use of FAN PUMP in Paper Plants:
          The finished slurry is diluted in silo with white water. The fan pump propels this diluted slurry for paper making towards the headbox. These pumps have been designed to reduce the pulsation, since the pump goal is to maintain constant weight overtime and avoid "Baring". At the inlet of the fan pump, thick stock, generally 3 to 5% consistency is diluted with white water. At the delivery end of the fan pump, the consistency of thin-stock around 0.3 to 1% solids. Mixing action of chemicals like fillers, acids and bases by paper makers before the fan pump happen within the fan pump.