HYDROSTATIC PRESSURE TESTING

•  The pipelines should initially be tested after approximately the first 400m of pipes have been laid. this practice should be repeated throughout the initial laying procedure and subsequently at intervals not exceeding one thousand metres
• It is advisable to pressure test the pipeline at each stage of laying to ensure that it has been laid and joined correctly.
• Fill with water from the lowest end, ensuring that no air is left in the pipe(See pipe bleeding).
• Always use suitable and approved pump with necessary connections, fittings and a calibrated pressure gauge.

  PIPE BLEEDING

• Inspect the installation to ensure that correct procedures have been followed.
• Fill in water starting from the lowest point.
• Purge out all the air from the system by filling water slowly from the lowest end. Bleeding valves should be inserted at the highest sections including the furthest end point of the line to be tested.
• Always ensure that no air is entrapped at any part of the system before before testing.

  AMOUNT OF PRESSURE

• Connect the pressure test machine and fill up the line gradually until required test pressure is achieved
• For normal waterworks practice, test pressures recommend as follows:-
  
  u-PVC and PE - 1.5 times the maximum working pressure of the pipe under test.
  m-PVC - 1.25 times the maximum working pressure of the pipe under test
  
  
• The system should maintain the test pressure for a period of 1hour or such shorter time as may be agreed upon between supplier and purchases
• Make good any defect revealed by the test and repeat the test until a satisfactory result is obtained.

The pressure test is satisfactory if:

•  There is no failure of pipe, joint, or fitting within the pipeline.
•  There is no leakage.
•  The measured make up rate is within the national standard or  installation specification.
•  The measured make up rate does not increase over time.
•  Drainage systems are filled with water to a maximum of 4 bars
   and the joints are inspected for leakage.
  
            
  
  

BURIAL DEPTHS

•  Proplastics manufactures PVC pressure fittings to world class  standards, including ISO 4422 and SABS 966.
•  Pressure rating is 16 bars at 20 degrees C.
•  The size range is 20mm and up to 110mm for elbows. The range
   is continually expanding.
•  All fittings are solvent cement joints or BSP threaded joints.
•  The range consists of elbows, tees, joiners end caps, adaptors
   and  reducing bushes.

REMEMBER

•  Treat the pipe properly - transport, handling, jointing and
   installation  - and you will never have call backs to fix it.
•  Proplastics PVC pressure and sewer pipes are designed for  underground use. Provide adequate protection if installed in
   sunny  areas
•  Make joints carefully - cleanness is essential
•  Don't take short cuts with backfill. Compact properly around the
   pipe  with good material. Sieve out rocks.