CALCULATION CATHODIC PROTECTION SYSTEM FOR PIPELINE

CALCULATION CATHODIC PROTECTION SYSTEM FOR PIPELINE

Under Ground Surface Pipe Area

The surface pipeline to be protected, as follows:
  • Length pipeline (L): 4.875 km
  • Pipeline Diameter (d) :  ∅ 12 inch = 323.85 mm = 0.32385 m
Total surface to be protected (A) = π * d * L
A =  4957.33 m2

Demand of Current

Total demand current to given formula:

Where :
= Demand Current (Amp)
= Surface area to be protected (m2)
= Current density per m2 (mA)
= Coating breakdown factor
Therefore:
mA = 0.992 Amp

  1. Resistance of Magnesium Anode for Kp 4+500





Rmg : Magnesium anode resistance (Ohm)
Lmg : Length of prepacked magnesium anode 32lbs (m) 0,9 m
Dmg : Diameter of prepacked magnesium anode 32lbs (m) 0,195 m
ρ : Layer Soil resistivity data at depth from survey  (Ohm cm) 5500 ohm.cm
Rmg = 25.3739 ohm

  1. Driving Voltage Anode
Net Driving Voltage The net driving voltage between Magnesium anode of -1.6  V
(Cu/CuSO4 reference) is 0.75 V (1.6 - 0.85).
 Close circuit potential (Volt) of magnesium is -1.6 volt

  1. Current of anode For Kp 4+500


Ia : Magnesium anode current output (Amp) = (Ec - Ea) : Rmg
Ipf : Required current
Ec : Protective potential (Volt) -0,85 Volt
Ea : Close circuit potential (Volt) -1,6 Volt
I = -0.85 – (-1.6) : 25.3739
I = 0.0296 A


  1. Sacrificial anode requirement

  1. Mass Metode
Total Sacrificial Anode weight to be given formula:
Where:
Y = Design Live Period (year)
S = Consumption rate (kg/amp-year)
= demand current (Amp)
f  = Utility factor
So, total weight;
kg
N = 13.68 ≈ 14 Pcs
  1. Current Output Method for Kp 4+500
Ip = Current Protective
Ia = Current Anode
N = 2.6 ≈ 3 Pcs

  1. Lifetime of anode

Current capacity = mass anode : Consumtion rate
Current capacity = 14.5 kg : 8 kg/amp.year = 1.8125 A.Y
Life of anode = Current Capacity (A.Y) x N  x f    :     IR
Life of anode = 1.8125 A.Y x 14  x 0.8 : 0.992 A
Life of anode = 20.46 Years > 20 Years

  1. Total Anode Required
The total Anode required is 40 Pcs, weight is 32 lbs or 14.5kg for each. Uses Current Method for better distribution.

Diposting oleh
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2 comments:

  1. Gilsulate International, Inc.11 October 2019 at 00:49

    Thanks for such an amazing blog.
    Pre Insulated Pipe Systems
    Pipeline Cathodic Protection

    ReplyDelete
  2. Great Western Corporation16 March 2021 at 23:18

    Glad to read the informative content that you have posted for us. This is an informative blog that has a detailed description of the mode of protection that has been used to achieve the desired result. The article is very well written as well. In addition to the content, there are many companies who have been providing these types of services at very reasonable quotes and their results are very accurate. These companies have well-trained and experienced engineers who can perform these tasks more efficiently. One of these companies is Great Western Corporation in North Bend Oregon USA where the engineers are very much experienced. They can perform this cathodic protection task very efficiently. They have more useful equipment and have more experience in performing the tasks.

    ReplyDelete

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