Different Types of Pattern Allowances in Casting



Pattern allowances:


There are some allowances which are responsible for the difference in the dimensions of the casting and the pattern. These allowances are considered when a pattern is designed for casting. In this article we will discuss those allowances -






1.     Shrinkage allowance:


After solidification of the metal from further cooling (room

Comments

Post a Comment

Popular posts from this blog

CAT Engine Course(Part 4) Cooling System

Image
Cooling System COOLING SYSTEM SCHEMATIC This diagram shows the basic cooling system. We can use it to see the components of the system and see how they are connected. In the diagram, we see the engine block, cylinder heads (separate heads for each cylinder), coolant manifold, housing of the temperature regulators (thermostats), water outlets bypass line from regulator housing to water pump, water pump, water inlet from radiator or heat exchanger, coolant line to the aftercooler, and the oil cooler. 1. water pump 2. oil cooler 3. cylinder heads 4. water manifold (right side) 5. aftercooler 6. temperature regulator housing 7. bypass line from regulator housing to water pump. COOLING SYSTEM FLOW Coolant flow comes from the elbow which is connected to the radiator or other heat exchanger into the center of the water pump. The cooler flow is divided at the outlet of the water pump. One partflows to the aftercooler; the other part to the oil cooler. Coolant sent to the aftercooler goes throu...
Read more

Log Mean Temperature Difference (LMTD) Method with Examples

Logarithmic Mean temperature Difference is used to measure the Heat transfer rate in double pipe heat exchanger. The rate of heat transfer is got from the formula - Q = U.A.LMTD . U= Heat Transfer Co-efficient A= Heat Transfer Surface Area LMTD=  Mean Temperature Difference LMTD is the logarithmic temperature difference between the hot and cold fluids passing through the each ends of heat
Read more

CAT Engine Course (Part 5) Lubrication System

Image
LUBRICATION SYSTEM The engine oil pressure has a normal operating range from 345 to 480 kPa (50 to 70 psi) and will be approximately 450 kPa (65 psi) at full load rpm. Flow of oil through the engine at rated rpm is approximately 340 litres/min (90 gpm). In this diagram of the lubrication system, we see the oil reservoir (sump in the oil pan), the oil pump (1) with a pressure relief valve (2); the oil cooler (3) with a bypass valve (2); the oil line from the cooler to the oil filter base/housing (4); with bypass valve (2) [one bypass valve for each filter]. The oil goes from the oil filters through the oil line to the oil elbow (manifold) on the left top front of the block. The oil pump takes oil from the sump and sends it through the oil cooler, oil filters, and into the oil elbow (manifold). Oil is sent to the turbochargers through outside lines (9) that are connected to the elbow on the left from (if turbocharger is top mounted). Turbocharger drain lines empty into the camshaft compa...
Read more