\B2.0  USING 'AGA'\b

	\BSTEP 1:\b
	  Install the program:

	     a) DOS version:
		Put the program diskette in drive A and type: A:\\INSTALL.  
		This will install the DOS-programs in directory C:\\ORIFICE 
		or show you how to install the program in a directory 
		of your choice.
         
	     b) Windows version:
		The Windows version of the program uses the Visual Basic 3.0 
		runtime DLL.  Put the program diskette in drive A.  From the 
		Microsoft Windows Program Manager, choose RUN from the FILE 
		menu and type: A:\\SETUP or double-click on the SETUP.EXE 
		file in drive A.  Setup will copy the program to directory 
		C:\\ORIFICE unless you make your own choice.  If you want the 
		program-icon to appear in another group window, move it to 
		where you want 'AGA' to be and delete the window group made by 
		Setup.  Save your selections.
          
	
	\BSTEP 2:\b
		Start the program by typing "AGA" from
		the DOS-prompt, or 'click' on the correct icon.
                                                                           


	The Disclaimer is shown before the main menu appears: 

			Gas Orifice
			Liquid Orifice
			Restriction Orifice - Gas
			Restriction Orifice - Liquid          
			EXIT
               


	\BSTEP 3:\b
	Calculation Options:
         
	After choosing type and method of calculation the input-screen 
	will appear.  For gas-calculations you have to enter specific gas 
	gravity, temperature and pressure.  You can also give molefractions 
	of N2, CO2 and H2S for sour gas calculations.

	The AGA-8 equation is used for calculating Z-factor (compressibility 
	factor) for natural gases.  The equation is complex, and calculation 
	time may be long depending on your computer-type.  The Redlich-Kwong 
	equation of state is used for air and nitrogen.

	For oil-calculations you have to enter specific oil gravity, 
	temperature and pressure.  It is also recommended to give molecular 
	weight of oil.  For water-calculations the input requirements are 
	salinity, temperature, and pressure.

	NOTE: 	It is assumed that all dissolved solids for water are 
	       	expressed as equivalent sodium chloride concentration.  

	The results are an orifice specification sheet giving the necessary 
	data for design of an orifice or evaluating an existing orifice.


	\BSTEP 4:\b
	Interpreting the results:
  
	The results will contain a few factors that you should know:
 
	\UANSI/API 2530-1991, Part 3 (AGA-3)\u
          
	The basic flow equation is:
 
		Qv = Fn*(Fc+Fsl)*Y1*Fpb*Ftb*Ftf*Fgr*Fpv*Sqrt(Pf1*hw)

	where	
  		Fn = 	Numeric conversion factor
  		Cd = 	Discharge coefficient = (Fc + Fsl)
  		Fc = 	Orifice calculation factor
  		Fsl= 	Slope factor
  		Y1 = 	Expansion factor based on upstream tap
  		Fpb= 	Pressure base factor, set to 1.0 (14.73 psia)
  		Ftb= 	Temperature base factor, set to 1.0 (60 deg F)
  		Ftf= 	Flowing temperature factor
  		Fgr= 	Specific gravity factor
  		Fpv= 	Super-compressibility factor
  		Pf1= 	Absolute flowing pressure based on upstream tap
  		hw = 	Orifice differential pressure, in H2O at 60 deg F


	The definition of these factors are given in Ref. 1.

	The above equation is often simplified to:

				Qv = C' * Sqrt(Pf1*hw)   

	where C' is called the Composite orifice flow factor.
       

	The velocity of approach factor is defined as:

     				Ev = 1/(Sqrt(1-Beta^4))

	The flow coefficient, Alpha, is defined as:

     				Alpha = Ev * Cd
       
	and orifice to pipe diameter ratio is given as

     				Beta = OD/PID 
	
	For other factors and the factors for pipe taps you are 
	advised to consult the standard (API-2530-1991, Part 3, Ref.1).