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I think some believe having a certificate is a magic item to hang on the wall. Others spend more time thinking about the place to hang the plaque, and placement on the their web page, than the purpose. They look at ISO or other certifications as an necessary evil to impress clients. They miss my point. What I identify sounds so ho hum. But people don't realise how many problems they have due to the issues I point out. Deming's work indicated 94% of the problems are in the system given to the workers vs the workers. Up to date through procedures are boring, so dismissed by many. I instituted a process which was driven by nothing more than a checklist that eliminated nearly all out repeat problems and avoided others. The check list started at order entry (which was outside my department and a major source of problems) through design release. I wrote about this a while back.http://www.jagengrg.com/blog/check-lists-simple-quality-control-tool

Good post, JAG. I must admit to being somewhat of an ISO 9000 skeptic, having seen very little value in it for places where I have worked. I do see your point about the value of requiring that everything be written down and looked at by many people. DrD

In simpler terms, pipe cannot be bent. It can only be connected with elbow/couplers to change the orientation. But tubes can be bent in 3 dimensional form.

Tubes are used for both HEAT&MASS Transfer. Pipes are used for only MASS Transfer.

All pipes are tubes. However not all tubes are pipes!

Different between tube and pipe : Tube:- 1. Tubes are more expensive than pipe due to tighter manufacturing tolerances. 2. Tubes can round, square and rectangular. 3. It is measured by outside diameter and wall thickness. 4. It is generally used for structural purpose, the OD is important and exact number. 5. Tubes are most stronger than pipes. Pipe: - 1. Pipes are always round in shape. 2. Pipe is measured by inside diameter. 3. Pipes are categorized as tubular vessels used in pipeline and piping system. 4. Pipe are typically available in large sizes then tubes...

Following are the reasonable points that conclude the high torque and efficiency of diesel engine. Diesel engine uses simple mechanism for combustion unlike in gasoline engine. Removal of ignition system not only makes the mechanism simpler but also reduces the risk of improper combustion due to damage in ignition system. In short burning of the fuel is easy and always accessible. This results in higher efficiency diesel engine. Diesel fuel is a heavier hydrocarbon in which carbon and hydrogen are strongly bonded with each other. And when energy is supplied in form of heat it gets explode releasing much higher energy then gasoline. In short diesel fuel has higher energy density then gasoline which results in huge explosion. One more factor for higher efficiency in diesel engine is its property of lubrication. Although all fuel has property of lubrication but diesel fuel has much higher lubrication then gasoline fuel. The compression ratio is much higher in diesel as compared to gasoline because in diesel engine air is alone compressed inside the cylinder and it’s a known fact that gas easily compresses then liquid. This is not so in gasoline engine because air-fuel mixture is compressed inside the cylinder. This higher compression gives higher heat and simultaneously higher torque. We can’t use Carnot cycle to get 100% efficiency but can use its principle to attain maximize efficiency. In diesel engine heat is added at constant pressure which results in higher utilization of heat energy to get maximize work output. These were the advantageous features of diesel engine but it has some demerits as well like it releases highly toxic gases, noisy, higher maintenance cost and starting problem (now starting problem is eliminated by using a bulb nearby to the cylinder) to heat the engine before ignition. And it is costlierthan gasoline engine but with optimum operation and good maintenance resolve all these problems.

A pipe is measured by Nominal Pipe Size (NPS) per Inch and Schedule number ( Thickness of pipe ) and tube is measures by Outside Diameter (OD) and BWG number ( Thickness of Tube) . The common Pipes size as ANSI are produced from size 1/8" to 48". Pipes are used for mass. fluid and gas transfer in different industrial. Tubes are manufactured from size 1/32" to 12". Tubes are used for heat transfer in Heat exchanges,boilers,vessels and also in fire burners ( size 2" and more) and as instruments tubes and also accessories tools in Turbines and Compressors.

which is better and in what case?

In casting we change the shape of material by changing it in molten form whereas in forging the work piece is heated and then hammered to change the shape.Forging is only for simple designs but casting can be used for complicated design.

Casting is a process in which the metal is melted at high temperatures and then poured into a mould to give it the desired shape. There are many casting methods: Sand Casting, DIe Casting, Lost Wax casting. In casting process the newly formed shape sometimes needs extra machining to get the desired surface finish. The cast parts can also incorporate defects because of air bubbles and internal stresses. Casting have some issues with metal selection. All the metals are not suitable for casting. It is sometimes associated with blow, scar, scab etc. errors. Forging is also very old method. Blacksmiths used to do forging with the hammer and anvil from an ancient time. It is the process where metal is heated in different temperature ranges and then hammered to get the desired shape. Depending on the temperature forging can hot, cold or warm. While forging there is a change in the grain structure of the metal which consequently makes it more tough and wear resistant. There are very less porosity and shrinkage defects.

Forging is stronger for a number of reasons, not least due to the internal stresses of the forged material bolsterring the crystaline structure and running along the shape of the forged item - effectively work hardening. Cast items are generally more brittle (due to high carbon steel being used predominantly to aid the liquid metal flow) and also the precipitation of the Carbon along the crystal walls in the material structure. (I cannot remember the correct nomenclature off hand (I recall "martensitic is in there somewhere), so, with regret, that's the best i can do on this at the moment!!!)

The Difference Between Casting & Forging Casting is the process where metal is heated until molten. While in the molten or liquid state it is poured into a mold or vessel to create a desired shape. Forging is the application of thermal and mechanical energy to steel billets or ingots to cause the material to change shape while in a solid state.