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Flexible Underground Piping Manual 18.3 Air Pressure Testing Procedures The air pressure integrity test procedure for the flexible supply piping is one and one half (1-1/2) times the normal operating pressure of the submersible pump, not to exceed sixty pounds per square inch (60 psi). Make sure the flexible pipeline is isolated from both the underground storage tank and the above ground product dispenser when conducting this test. All pressure testing should be conducted by qualified and experienced personnel. Do not attempt to disconnect couplings, caps, or plugs unless the air pressure has been released. NOTE: Testing requirements must be in accordance with all applicable codes. 18.3.1 Air Pressurize Gradually apply air pressure into the flexible piping line. Do not exceed sixty pounds per square inch (60 psi) or 416 kPa 18.3.2 Air Pressure Holding Maintain pressure for a minimum of three hours, making sure that there is no drop in pressure. Note: Significant temperature changes can result in a pressure reading differential. 18.3.3 Air Pressure Holding for Coax PRE -BACKFILL Maintain pressure for a minimum of three hours. POST -BACKFILL Maintain pressure for a minimum of three hours. NOTE: Do not close off or apply pressure to secondary jacket until primary pressure is maintained for a minimum of one hour. 18.3.4 Test Tube Gauge Check During pressurizing, check the reading on the test gauge which should be connected to the test tube of the inter- connected interstitial line. Any increase in pressure will indicate a leak. 18.3.5 Soap Test During the pressurizing period, apply a soapy water solution to all piping connections and inspect for bubbles. 18.4 Hydrostatic Testing Procedures (if applicable) The recommended hydrostatic pressure integrity test procedure for the flexible supply piping is one and one half (1-1/2) times the normal operating pressure of the submersible pump, not to exceed sixty pounds per square inch (60 psi). Make sure the flexible pipeline is isolated from the underground storage tank and the above ground product dispenser when conducting this test. All pressure testing should be conducted by qualified and experienced personnel. Do not attempt to disconnect couplings, caps, or plugs unless the air pressure has been released. Note: OPW-FCS recommends hydrostatic testing on all sumps after installation is complete to check for proper sealing of joints and connections. 18.4.1 Water Filling Gradually introduce water at the lowest point into the piping system and bleed off air at the highest point in the piping W FIexWOR KS BY DPW FURLING CONTAINMENT SYSTEMS system through an open valve. The hydrostatic pressure applied should not exceed 60 psi. 18.4.2 Pressure Hold Inspection Maintain pressurization for a minimum of one hour making sure there is no drop in pressure. Significant temperature changes can result in a pressure reading differential. During the pressurizing period, inspect all piping connections for leaks. 18.5 Supply System Filling After the supply piping system has been integrity tested and connected to the product dispensers, filling of the pipe line may commence. There should be a controlled method for filling the supply line which provides an adequate means of removing air from the lines. Do not start pumps with empty lines, as it may damage the pipe and its connections. Small amounts of trapped air should dissipate under normal operations. Make sure that the pressure rating of the submersible pump does not exceed that of the maximum operating pressure of the pipe. 19.0 PERIODIC LINE LEAK DETECTION Local or federal regulations may require periodic line leak detection tests be performed on the installed piping system. Testing requirements affect both suction and pressure piping systems. Atypical requirement is that the piping lines must be tested on an annual basis at one and one half (1-1/2) times the normal operating pressure. The typical test method will require detection of 0.10 gallons (.3785 liters) per hour with a 95% probability of detection and a 5% probability of a false alarm. The typical test procedure requires the piping be isolated from the tank and the piping line pressurized to 1-1/2 times the normal operating pressure. A test apparatus which is connected to the piping line will then measure the bleedback volume of the piping system. Acceptable bleedback volumes on different types of piping systems will vary due to their inherent expansion and contraction characteristics. Therefore, modifications in the testing procedures are required for piping systems which have significant expansion and contraction characteristics. This characteristic is measured in the average volume increase, per linear foot under a standard test pressure. 19.1 FlexWorks Piping Expansion Characteristics FlexWorks Piping is a multi -layer reinforced smooth bore flexible pipe which demonstrates only minor expansion and contraction characteristics during pressurization and depressurization, similar to that of fiberglass piping. These physical characteristics reduce the affect on the "bleedback tolerances" permitting a more accurate testing procedure. Piping Expansion Characteristics Pipe Description Volume Increase 1-112" Flex Flexible Piping +0.0015 2" Fiberglass Piping + 0.00045 1-1/2" Flexible Connectors + 0.0060 "Volume increase = gallons per lineal foot at 60 psi pressure. Does not apply to Flex Plus piping.