In Hydrotest by section,the distance per section shall not be over 35km,and heght differnce shall not exceed 30m.
1.Water Filling. A Saparation Pig is required while filling water for HYDROTEST,to avoid any air into the target pipeline affecting the result.Apply water pump to fill the pipeline,pushing the saparation pig from the launching point to the End so as to full fill the pipe,make sure at least 95% of the pipe is full.
2、Pressure Raising. Keep filling water until it reaches the required pressure for High Pressure Test.During the course,the pressurizing shall stop when the reaching 30% and 60% of the design pressure for 20-30mins,check for leaks.If alright,carry on pressurizing to require,but the speed shall be controlled within 0.1mpa so as not to damage the pipeline.
3、Pressure maintain. When raised to high pressure,maintaining is required.pressure lose less than0.1mpa and no more than 1% of test pressure is considered acceptable.After High Pressure Test Accepatance,release it to design pressure for sealing check.In this course,the pressure gauge,tempreature&pressure recorder at both ends start to work,and record and check at times is required.
4、Depressurizing and Dewatering.
After acceptance of Pressure test, qickly release to zero the pressure at a required rate,and apply ampressors to clean the water out of the pipe.If,during pressure maintaining,the pressure lose exceeds the requirement,pressure release is strongly recommended find the problems.
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