Scribd
Upload
831 views1 page

Lag Time Calculation Sample

This document provides calculations for determining the lag time of process gas chromatographs and analyzers. It details equations that use parameters like line length, tubing volume, pressure, temperature, and flow rate to calculate lag time in minutes. An example calculation is shown for a specific analyzer tag number with inlet/outlet conditions and primary/secondary sampling system specifications. The results provide the volume, lag time, actual and normal flow rates for both the primary and secondary systems.

Uploaded by

violeta
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
831 views1 page

Lag Time Calculation Sample

This document provides calculations for determining the lag time of process gas chromatographs and analyzers. It details equations that use parameters like line length, tubing volume, pressure, temperature, and flow rate to calculate lag time in minutes. An example calculation is shown for a specific analyzer tag number with inlet/outlet conditions and primary/secondary sampling system specifications. The results provide the volume, lag time, actual and normal flow rates for both the primary and secondary systems.

Uploaded by

violeta
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF, TXT or read online on Scribd
You are on page 1/ 1

Contractor: OWNER:

GACHSARAN PETROCHEMICAL COMPLEX

OLEFIN PLANT

Vendor: PMC:
Calculations ( Lag Time)
For Process Gas Chromatographs And
Analyzer House Package

VENDOR DOCUMENT N° CONTRACTOR DOCUMENT N°


SND-VD-30-156101-PR-CNT-007-A4-02 G110-VD-30-156101-PR-CNT-007-A4-02

(1)

31 4 14.7 520
0 1 (2)
2 1 32 460 4 Process Analyzers, API Recommended Practice 555
THIRD EDITION, JUNE 2013
Lag Time = is the sample transport time in (minutes);
P1 = is the pressure in sample volume whose lag time is to be calculated, in (psig);
P2 = is the pressure at point of flow measurement in (psig);
L = is the total line length in (ft);
V = is the tubing volume in (cc/ft);

Volume / ∗ "# $ /2 & ' () ** $ +


∗ ) ' $ 1 /L ft (3)

Normal Flow Rate = is the flow rate in cc/min at standard conditions 14.7 psia, 60 °F (Ncc/min) ;
T = is the temperature in (°F).
Note
Tag No.: 30 AE 130071 / AT 130071 Lag Time: Max( Sec): 30
Calculation

Phase: Gas
Tapping Point

Density (kg/m3): 13.5


Viscosity (cP): 0.01
Temperature (°C): 50 323.15 K
Pressure (barg): 18.7 19.7 bara
Secondary Sampling System Primary Sampling System

Inlet Temperature (°C): 60 333.15 K Result


Inlet Pressure (barg): 18.7 19.7 bara Volume (lit): 0.12
Volume Filter(cc): 35 Lag Time(s): 7.76
Regulator: Yes Actual Flow Rate (cc/min): 904.87
Output Pri. Press. (barg): 2 3 bara Actual Flow Rate (lit/h): 54.29
Outlet Temperature (°C): 30 303.15 K Normal Flow Rate (Ncc/min): 15216.55
Normal Flow Rate (Nlit/h): 912.99

Inlet Temperature (°C): 30 303.15 K Result


Inlet Pressure (barg): 2 3 bara Volume (lit): 2.00
Volume Filter(cc): 35 Lag Time(s): 22.24
Regulator: No Actual Flow Rate (cc/min): 5406.93
Outlet Pressure (barg): 2 3 bara Actual Flow Rate (lit/h): 324.42
Normal Flow Rate (Ncc/min): 15216.55
Normal Flow Rate (Nlit/h): 912.99

Primary Tube Length (m): 5


Primary Tube OD (in): 0.25 Total Volume (lit): 2.12
Primary Temp. Outlet (°C): 30 Primary Actual Flow Rate (lit/h): 54.29
Primary Pre. Outlet (barg): 2 Normal Flow Rate (Nlit/h): 912.99
Result Secondary Tube Length (m): 120 Secondary Actual Flow Rate (lit/h): 324.42
Secondary Tube OD (in): 0.25 Normal Flow Rate (Ncc/min): 15216.55
Secondary Temp. Outlet (°C): 30
Secondary Pre. Outlet (barg): 2

Anlayzer Input Flow: 564.31 Ncc/min Bypass Flow: 14652.24 Ncc/min


Rotameter

REV 02 Anlayzer Input Flow: 33.86 Nlit/hr Bypass Flow: 879.13 Nlit/hr
Analyzer Input Press.(barg): 2 Bypass Press.(barg): 2
Analyzer Input Temp.(°C): 30 Bypass Temp.(°C): 30

You might also like