Ignition Lag or Delay Period:
It is the duration between the occurrence of the spark at the spark plug and the duration of the combustion curve from the motor curve. Factors influencing this phase are:
Nature of fuel
Temperature of the flame between the spark plug electrodes
Important properties of Engine fuel: Knock rating; Volatility; Calorific value; Gum content; Sulphur content; Aromatic content;
Non Destructive Testing (NDT) is a method of testing the material’s characteristics such as physical, chemical and structural components to perform their function in a cost effective way. In this, components are examined / evaluated without destroy / damage of the product. NDT tests conducted in the parts aren’t damage the raw materials as such happened in destructive methods and it guaranteeing the safe operation of the parts. NDT is no way alters the components in any type of inspection. NDT is carried out widely for the conditioning monitoring (industrial inspections) of the plants such as aerospace, automobile, manufacturing and construction.
Pneumatic conveying systems can be classified on different basis of consideration. These basis are listed below:
On average particle concentration (modes)
On air pressure (Types of systems)
On air supply arrangement
On solid feeder type
Of these, the first two are very important and often influence the choice of the specific design for a given material, loading and delivery condition and the distance to be covered.
The basic Principles of Pneumatic conveying stated by Great Alexander in 100 BC itself. In pre historical age Romans used Water supply pipelines and sewage disposable systems. Chinese conveyed Natural gas through Bamboo’s. These are the evidence for transporting physical objects in Pneumatic tubes.
Objects of Lubrication: Primary: To reduce friction between moving parts so as to reduce Power loss Wear of the moving parts Secondary: To provide cooling effect To provide cushioning effect To provide cleaning action To provide sealing action Purpose of Lubrication: To reduce friction To cool down moving parts To prevent corrosion (component wear from chemical reaction with air and
Valve Actuating Mechanisms: Each valve must open at the proper time, stay open for the required length of time and close at the proper time. Hence the timing of the valves are controlled by valve actuating mechanisms. Intake valves are just open before the piston reaches the Top Dead Centre (TDC), and exhaust valve remain open after TDC. At this
There are numerous brazing methods are available. Some of them are Induction Brazing, Furnace Brazing, copper brazing torch, infrared brazing, laser brazing, dip brazing, resistance brazing.
Brazing Technology is a joining process in which a filler metal is melted and dispersed by capillary action between the faying surfaces of the metal parts being joined. No melting of the base metals occurs in brazing; only the filler metals are melted. In brazing, the filler metal (also called as brazing metal), has a melting point is above 840° F (450° C) but below the melting point of the base metal to be joined. Tensile strength of the joint is about 40000 psi.
Underwater welding offers a mode of assembly or repairs the structures underwater. It is a type of technology for repairing marine structures. Unconventional methods such as clamp and grout repairs (which may set up inappropriately high loading on offshore structures), and the use of bolted flanges for the tie-ins, are not necessarily always satisfactory.