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11 Primary system Conversely,overnight decreases in pressure due to cooling from afternoon to testing (cont'd) early morning are normal and do not necessarily indicate a leak. • After testing,maintain 5 to 10 psi(35 to 70 kPa)in the system during subsequent construction so that damage caused by stakes,excavation equipment,etc,.can be detected and corrected before pavement is installed or product is pumped. 12Containment Pneumatic testing system testing Plan tests carefully and carry them out with all due precautions.Pressurizing equipment should be suited to the size of the system and the pressure required and should be operated by qualified and experienced personnel only.Pressure sources should be capable of approaching test pressure gradually. Use gauges with a full-scale reading of no more than twice the test pressure.Do not use a 100 psi gauge for a 10 psi test.Use reliable gauges calibrated against a dead weight tester zeroed for atmospheric pressure. The volume of air in the interstitial space is very small,so use of a regulator is recommended to control the pressure during filling of the line. Pneumatic testing at approximately 30 psi is recommended and is the preferred method of testing containment piping.If flexible terminating sleeves are used,the test pressure is limited to 5-10 psi.The molded terminating assembly must be used for all tests over 10 psi. Provisions for testing and monitoring The terminating sleeves with test valve are equipped with a''/o inch Schrader valve which can be used to attach pressurizing equipment.It may be necessary to remove the internal valve priorto attaching pressurization equipment.Use proper tool to do so. Important. Before checking the system for integrity,allow 10 to 20 minutes for the pressure to stabilize.Do not adjust fittings while system is under pressure.If a loss of pressure is indicated,disassemble the mechanical connection,remove the O-rings and inspect for foreign material or damage to the O-ring.If the sealing surfaces are clean,relubricate the O-rings and reinstall. Should gauge readings fail to remain stable and the testing is being done pneumati- cally,use a soap solution to locate leakage. 13 Simultaneous Simultaneous testing of the primary and containment systems testing Testing of the primary and containment portions of Dualoy 3000/LCX can be done simulta- neously.This procedure is possible because the small volume of the interstitial space in the containment is very sensitive to air volume changes.Large changes in pressure will occur when small amounts of air are gained or lost.The advantages of this this procedure are: •reduces the time needed to inspect the system(done in one visit by the inspector). •the system can be pressurized prior to the inspection,eliminating a rush to get the system closed before the inspector visit is scheduled. •improved safety. Pressure testing of the two systems is done at two different pressures.Normal practices are to test the primary pipe at a higher pressure than the containment.As before,Ameron advises that pressure testing with compressed air can be hazardous and precautions should be taken to minimize the pressure used and the potential damage which could occur should a sudden failure occur.The simultaneous testing of the Dualoy 3000/LCX product actually enhances the safety aspects of the testing due to its low volume(reducing the potential energy stored at a given pressure)and the fact that both the primary and containment joints can be assembled prior to testing(failure of both joints at the same connection would have to happen to allow significant pipe movement).