• The purpose of the site pressure is to ensure that installed section of line 
  under test and all joints and fittings included in the section will 
  withstand the design working pressure plus a safety margin without leakage.
  

1.  Before pressure testing the following guidelines should be observed.
   End caps are mounted on all ends of the pipeline.
   Insert air bleed valves at all the highest points along the pipeline.
   Allow 24 hours after welding before test.
   The line should be filled with water 24 hours prior to the start of 
   the test.Ensure that the system is entirely ventilated.
   Backfill the pipeline before test.
   Leave joints exposed 
   Test with all valves fully open 

2.  During pressure testing the following should be observed.
   Ensure that all air bleed valves are open and working. 
   Slowly fill the pipeline with water avoid damage due to pressure
   surge gradually raise the pressure to a pressure corresponding to
   1.5 times that nominal pressure class the pressure is maintained 
   for 2 hours. Supplementary filling of water allowed. During the 
   following 60 minutes water should not be added. After 60 minutes 
   the pressure is measured and the water is added until the pressure 
   is again 1.5 times nominal pressure class.
   The fall in pressure and the amount of water added should not exceed 
   the following limits:
   Pressure drop in percentage of the initial pressure = 2% 
   Water quantity in liters / meter = 0.2 Di - 0.001 + DV
   Where DV = 0.05 x d 
   Di  is the inside diameter. 
   

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