What is Difference between stamina and strength?

Strength is capability over a short length of time and Stamina is the ability to keep going continuously.

What is Hydrostatic System?

Hydrostatics is the study of fluid bodies that are

• At rest
• Moving sufficiently slowly so there is no relative motion between adjacent parts of the body

For hydrostatic situations

• There are no shear stresses
• There are only pressure forces that act perpendicular to any surface.

It’s a closed loop hydraulic systems. It comprises of motor and pump. Here pump supplies energy to motor and motor gives return energy to pump supply.

What is Cotter joint?

A cotter joint is used to connect rigidly two co-axial rods or bars which are subjected to axial tensile or compressive forces. Here shaft is locked in place by a smaller pin that passes through the side of the lug and partly or completely through the shaft itself. This locking pin is named as cotter.

How is the excess discharge pressure prevented?

Discharge pressure prevented by a pressurized spike cushion. Here the system employs a pressurized cushion of air and a two o-ring piston, which permanently separates this air cushion from the water system. When the valve closes and the water flow is suddenly stopped, the pressure spike pushes the piston up the arrester chamber against the pressurized cushion of air. The air cushion in the arrester reacts instantly, absorbing the pressure spike that causes water hammer.

What is the difference between Strainer and Fitler?

Strainer for coarse size, Filter is more accurate than Strainer.

What is the position of Piston Ring?

In 180 degree angle the Top ring, Second ring and Oil ring are fixed. Position the ring approximately 1 inch gap below the neck.

Why Deareator are placed at Hieght, In Thermal Power Plant?

To build a Very high pressure and the temperature for a boiler feed water pump and it discharge high pressure water to the boiler.

And to provide the required Net Positive Suction Head (NPSH) for the BFW pump and to serve as a storage tank to ensure a continuous supply of feed water during rapid changes in BFP.

What is meanst by One Tonn Air-Conditioner?

1 ton refrigeration means 210 kJ/min extracts heat from thesystem.

State 1st Law of Thermodynamics?

HEAT AND MECHANICAL WORK ARE MUTUALLY CONVERTABLE. ENERGY CAN BE CREATED NOR BE DISTROYED BUT IT CAN BETRANSFERED FROM ONE FORM TO ANOTHER FORM.

If you heat a steel pipe with the hole at center, does heat affects the hole diameter?

It gets bigger.

What is priming?

Pump casing must be filled with liquid before the pump is started, or the pump will not be able to function. If the pump casing becomes filled with vapors or gases, the pump impeller becomes gas-bound and incapable of pumping.

Types of pumps?

– Positive Displacement

– rotary lobe pump, progressive cavity pump, rotary gear pump, piston pump, diaphragm pump, screw pump,gear pump, Hydraulic pump, vane pump

– Centrifugal Pumps

– end suction pumps, in-line pumps, double suction pumps, vertical multistage pumps, horizontal multistage pumps, submersible pumps, self-priming pumps, axial-flow pumps, regenerative pumps.

What is octane number in fuel?

– The octane rating of Gasoline is measured in a test engine, and is defined by comparison with the mixture of2,2,4-trimethylpentane (iso-octane) and heptane which would have the same anti-knocking capacity as the fuel under test: the percentage, by volume, of 2,2,4-trimethylpentane in that mixture is the octane number of the fuel. For example, petrol with the same knocking characteristics as a mixture of 90% iso-octane and 10% heptane would have an octane rating of 90.

What is added in LPG to detect leakage?

– Methyl Mercaptan

Pascal law ? Applications?

– Pascal’s law or the Principle of transmission of fluid-pressure states that “pressure exerted anywhere in a confined incompressible fluid is transmitted equally in all directions throughout the fluid such that the pressure ratio (initial difference) remains the same.

Application- Hydraulic jacks, Car lifts, Fork Lifts

Can you transfer the heat energy from cold body to hot body?

Yes, with external work. Eg : Air conditioner

What is hogging and sagging?

Hogging and sagging describe the shape of a beam or similar long object when loading is applied. Hogging describes a beam which curves upwards in the middle, and sagging describes a beam which curves downwards.

What Bernoulli’s Principle?

In fluid dynamics, Bernoulli’s principle states that for an inviscid flow, an increase in the speed of the fluid occurs simultaneously with a decrease in pressure or a decrease in the fluid’s potential energy.

Difference between single acting and double acting pump?

– In single-acting machines the compression takes place on only one side of the piston; double-acting machines use both sides of the cylinder for compression. The flow is continuous in double acting and in single acting the flow is not continuous unless there is a surge vessel.

What is VSD?

– Variable Speed Drive

What is conduction, convection and radiation? Give Examples?

– Conduction or diffusion

The transfer of energy between objects that are in physical contact

Convection

The transfer of energy between an object and its environment, due to circular fluid motion

Radiation

The transfer of energy to or from a body by means of the emission or absorption of electromagnetic radiation

Mention flow measuring devices?

– Venturimeter, Rotameter etc.

Classify Carbon Steels on basis of carbon content?

Low-carbon steels contain up to 0.30% C. The largest category of this class of steel is flat-rolled products (sheet or strip), usually in the cold-rolled and annealed condition. The carbon content for these high-formability steels is very low, less than 0.10% C, with up to 0.4% Mn. Typical uses are in automobile body panels, tin plate, and wire products.
For rolled steel structural plates and sections, the carbon content may be increased to approximately 0.30%, with higher manganese content up to 1.5%. These materials may be used for stampings, forgings, seamless tubes, and boiler plate.

Medium-carbon steels are similar to low-carbon steels except that the carbon ranges from 0.30 to 0.60% and the manganese from 0.60 to 1.65%. Increasing the carbon content to approximately 0.5% with an accompanying increase in manganese allows medium carbon steels to be used in the quenched and tempered condition. The uses of medium carbon-manganese steels include shafts, axles, gears, crankshafts, couplings and forgings. Steels in the 0.40 to 0.60% C range are also used for rails, railway wheels and rail axles.

High-carbon steels contain from 0.60 to 1.00% C with manganese contents ranging from 0.30 to 0.90%. High-carbon steels are used for spring materials and high-strength wires.

Ultrahigh-carbon steels are experimental alloys containing 1.25 to 2.0% C. These steels are thermomechanically processed to produce microstructures that consist of ultrafine, equiaxed grains of spherical, discontinuous proeutectoid carbide particles.