Understanding about Measuring units used in LPG industry

Confused about Units?? Don't worry, this course is for you.

Objective ... 

To clearly understand units used in LPG industry for expressing  quantities of various parameters of LPG,  and also using in formulae. Various systems used and conversion from one to another system

About the course ...

It's a "Must have sufficient knowledge and Clarity" type of topic that will be covered in this course, for all who  are working in industry related to LPG at any stage.

In engineering, every parameter or characteristic / property needs to be measured and expressed. For example Length in meter, centimeter, feet, inches. Weight in kg, gram, ton, Lbs. Time in hour, minute , second and so on. More complex are flow rate, pressure, heat transfer, viscosity, heat capacity, and so on. There are many parameters like this. These need "units" for measurement . The units will be always accompanied by some number, telling how many such units.

 LPG properties can be grouped as Physical, chemical, thermodynamic, electrical, molecular. Properties/parameters are expressed in different units by different countries, for different applications. Time based parameters can be with reference to volume or weight.  For example, flow rate is expressed in litre/sec, kg/sec., CFM, CFH, Lbs/min, etc. Combination of weight unit and time unit can cause further multiplicity of units, like m3/min, m3/hr,  MMSCFD (Million standard cubic feet per day) for large quantities of natural gas, BPD (barrel per day) for crude oil flow measurement;

Another example is heat capacity (calorific value) of LPG (fuels in general) is expressed in k.cal/kg,  k.ca/lit,  btu/lb,  Mega-joules/kg(MJ/kg),  Kilowatt-hour/kg  (KwH/kg) and many more. All this can be per unit volume also. A simple calculation like flow velocity through pipe can give wrong results if values are placed with non-consistent units. e.g. Just try to calculate 48m3/hr flow thr  3" sch. 40 pipe. What is the velocity in m/sec? You will realise the pitfalls.

This is all confusing and can create serious problems while using the data. Multiplicity of measuring unit like Metric(MKS), SI system, Foot-pound-second system(FPS) increase the complications.  Data charts use variety of all units. You need to convert data from one system to another which you may be using at that moment'

This course is an effort towards removing that confusion by explaining the basic units, (also known as Fundamental or independent), derived units and conversion of derived unit, from one system to other. Kg/min to M3/min, using density. Many formulae contain some constants which are unit specific. Consistency in units is very important to get correct end result.

For LPG, properties which are commonly required for applications, are ----

Volume, density,  Specific gravity,  Specific heat, boiling point, Latent heat, Critical pressure and temp, Phase change temp, Viscosity.

Parameters which are regularly used are ---- Pressure, Temperature, Pipe Flow velocity, Flow rate, Pressure drop, Heat transfer rate, Thermal expansion, and may more.

It is essential to get sufficiently familiar with these parameters and  their units.

Who will benefit by this course ....

Everyone who has to do calculations related to LPG equipment  design, selection;  plant capacity calculations, costing; LPG consumption calculations and many others. Business owners, especially from commercial background. Marketing engineers, project engineers.

Quality assurance personnel.

Lack of clarity about this can result into  mistakes in design, serious hazardous situations, delay in project execution, loss in business.