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Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance

Arthur D. Bosshart II TECO Energy 07/09/08

Arthur D Bosshart II TECO Energy

Table of Contents
Abstract ….………………………………………………………………………….. Introduction …………………………………………………………………………. Field Tests and Analysis …………………………………….…………………….. Proposed Procedure ………………………………………….……………………. Ideal Testing Conditions ……………………………………….………………….. Conclusions ……………………………………………………….………………… Acknowledgments ………………………………………………………………….. Bibliography ………………………………………………………………………… Appendix ……………………………………………………………………………..
Calculations ……………………………………………………………………………… Example spread sheet walkthrough ……………………………………………...…… Assumptions ……………………………………………………………………………... Nomenclature ……………………………………………...……………….….………… Simplified Field Method …………..……………………...….…………….….………… F) APT Lookup Table …...…………………………………...……………….….………… G) Compliance Curve …………..……..………….……...….……………….….………… H) Simplified Field Method Sample Calculation ……………...………….….………… I) Field Pressure Testing Packet …...…………………………...………….….………… J) Completed Line Pressure Test Worksheet ……………...………….….………...…… K) Calculation of the “P” Coefficient …...…………………………...……….….………… L) Calculation of a Specific APT Value ……………...………….….…………...…...……
A) B) C) D) E)

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Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance

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Arthur D Bosshart II TECO Energy

Abstract
The API 1110 pressure test method is used for determining leaks within piping segments in contact with soil or above water. A criticism of this current method is that it does not account for temperature effects on the contained substance in the piping. These temperature variances affect the measured pressure during a test and depending on testing conditions can pass a failed test or fail a passed test. The proposed alternate method and associated calculations account for a temperature change that can occur during a pressure test and correlates an unaccounted volume of substance to the Table BPP located in Rule 62-762.601, Florida Administrative Code (F.A.C.) to determine pass or fail.

Introduction
The purpose of this paper is to define the allowable pressure tolerances of the API 1110 pressure test method between the theoretical pressure change and the actual pressure change associated with a temperature change of a contained substance within piping during a pressure test. A volumetric difference, over a testing duration, can be associated with the difference

between the theoretically calculated and actual measured pressures and then correlated to the Table BPP found in Rule 62-762.601, F.A.C. to identify a passed or failed test in accordance with API 1110 pressure test method. Ideal testing conditions will then be identified to ensure accuracy and confidence in a given pressure test. There are a number of influences that affect the final results of pressure tests such as the change in substance temperature within the piping, ambient temperature changes, piping temperature change, piping material, substance within the pipe, thermal expansion rates, compressibility, percentage of pipe directly in contact with sunlight, and volume of piping isolated for testing. Some of the factors noted above have a greater effect than others. The most important operational condition to monitor, other than pressure, is the temperature of the substance within the pipe. Depending upon the type of substance, a change in temperature can have dramatic results. Using #2 diesel fuel as an example, if a temperature change of 1 F occurs within an isolated volume, the pressure will increase or decrease by 70 psi
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Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance

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initial ambient temperature. Field Tests and Analysis For purposes of this paper. energy transfer is the reason why a substance’s temperature will increase during a test. there will be a substantial delay between the ambient or environmental temperature change and the temperature change of the substance.Arthur D Bosshart II TECO Energy to 100 psi. final ambient temperature. If the heat capacity of the contained substance and thermal conductivity of the substance’s surroundings are accounted for. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 4 . pressure changes. The pressure will vary depending on the volumetric thermal expansion rate of #2 diesel fuel and the piping material. This reasoning is not accurate. two examples of API 1110 pressure tests that were recently conducted in the field at TECO Energy facilities will be examined to illustrate the temperature changes. the energy flux. Without monitoring the temperature of the substance within the pipe. final exterior pipe surface temperature. initial interior pipe surface temperature and final interior pipe surface temperature. If a portion of the piping is exposed to the sun the exterior surface temperature of the piping will increase. the heat capacity of the liquid. schedule of the piping. there is no protocol in the current API 1110 pressure test method that requires that the liquid temperature be monitored throughout the duration of a test. initial exterior pipe surface temperature. Currently. The magnitude of the increase is determined by the solar radiation intensity and if the pipe is coated with an energy absorbing color like black then a greater temperature change will occur. Given that the piping section being tested is isolated. and energy transfers between materials. Another important factor to account for is the energy transfer between the outside environment and the pipe and between the pipe and the substance contained therein. This is a potential deficiency of this test. pressure fluctuations cannot be accounted for other than reasoning that a product loss had occurred meaning that there is a leak in the pipe that was pressure tested. The temperature change is determined by the thermal conductivity of the piping material. Fourier's law describes linear heat flow rate between two surfaces. This is because liquids are not easily compressible like gases. These relationships are described in Fourier's law.

Arthur D Bosshart II TECO Energy Example #1: This API 1110 pressure test was conducted at the TECO Big Bend Plant on February 12. 2007 located in Apollo Beach. to 3:19 p.m. The test was performed on a Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 5 .m. FL from 2:00 p.

the rate at which heat is conducted through the carbon steel piping. and the heat capacity of the contained liquid. o o o o o o Although the ambient temperature was only around 70 F. and radiation reflected upon the pipe’s surface from the water below. the temperature of the #2 diesel fuel only increased by 1. The change in ambient temperature appears to have had a smaller impact. When using Fourier's law to describe the heat transfer occurring within this test. and the heat capacity of the #2 diesel. and into an aboveground storage tank system. Readings were recorded every 15 minutes throughout the testing duration and before depressurization. the final reading was recorded at 234psi and 70 F. respectively. The temperature recordings were of the ambient environmental temperature. it is important to note the pressure increase and the temperature increase. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 6 . one needs to look at the piping schedule. radiation diffused through the surrounding environment. the temperature of the pipe’s exterior surface was most likely around the range of 80 F to 85 F. When analyzing the data associated with Example #1. Although the ambient temperature increased by 5 F. The initial pressure and temperature readings were recorded at 107psi and 65 F.Arthur D Bosshart II TECO Energy section of piping nearly 900 feet in length constructed of carbon steel. The #2 diesel fuel did not reach a thermal steady state with the pipe’s exterior surface because of the length of the test. Contained within the pipe is #2 diesel fuel. This portion of piping is entirely aboveground and transports fuel from a pump house.285 F temperature rise occurred mainly due to solar radiation incident upon the pipe’s exterior surface. the energy transfer through the pipe. the temperature of the piping exterior surface. over a canal. This 1. The weather conditions during this test were partly cloudy with a light breeze. o o This temperature difference is attributed to the energy absorbing ability of the pipe’s exterior coating and the solar radiation directly incident upon the pipe. along the side of the canal.285 F.

m.m. The test was performed on a Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 7 . FL from 3:20 p. 2007 located in Apollo Beach. to 4:40 p.Arthur D Bosshart II TECO Energy Example #2 This API 1110 pressure test was conducted at the TECO Big Bend Plant on February 12.

then the test passes. Although the ground acts as an insulator. heat flow will still occur from the ground surface to the soil in contact with the pipe. respectively. one can see this delay in energy transfer when one analyzes the fourth and fifth readings. the pipe is not absorbing energy from solar radiation incident upon the exterior surface. from the soil in contact with the pipe to the pipe’s exterior surface. it is important to note the relatively stable pressures and temperatures recorded.1 psi pressure drop. When looking at the first four readings of the test it is important to note that the temperature decreases and the pressure increases. This portion of piping is underground and transports fuel from another portion of piping to an aboveground day storage tank system. in length and constructed of carbon steel.Arthur D Bosshart II TECO Energy section of piping between 400 and 600 ft. In the two examples given. The initial pressure and temperature readings were recorded at 160psi and 72 F. When analyzing the data associated with Example #2. Note that only a 0. from the pipe’s exterior surface to the pipe’s interior surface. the final reading was recorded at 160psi and 70 F. This occurs because underground temperature remains relatively stable throughout the day because the ground acts as an insulator and limits the impact of the ambient temperature fluctuation.15 F change occurred to cause a 14. If there is no substantial pressure drop. Contained within the pipe was #2 diesel fuel. The weather conditions during this test were partly cloudy. Also. Given the above information. o The analysis of this pressure test’s results includes a comparison of the initial recorded pressure to other recorded pressures during the test and evaluation for a substantial pressure drop to confirm a failed test. both tests passed because neither fell substantially below the initial pressure Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 8 . o o The temperature recordings were of the ambient environmental temperature. Temperature under the soil surface remains stable because heat transfer occurs through multiple layers with varying thermal conductivities. and all the way to the ground surface. to the cooler exterior surface of the pipe. heat is flowing in the opposite direction from the warmer liquid to the cooler interior surface of the pipe. During the time these last readings were taken. Readings were recorded every 15 minutes throughout the testing duration and before depressurization. and from the pipe’s interior surface to the #2 diesel fuel.

See Appendix A for an example calculation. Pressure levels observed during API 1110 pressure testing will not cause piping deformation because the observed pressure levels used during testing are well below the design pressure limits of the piping system.8 as the stress in a pipe wall. the potential for inaccuracies is decreased substantially and facilitates the development of an additional procedure that can be used in conjunction with the API 1110 pressure test method to meet the standards in Table BPP of Rule 62-762. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 9 . This proposed procedure will account for temperature change during a pressure test to ensure compliance with the requirements of Table BPP table of Rule 62-762. the complexity of Fourier's heat transfer calculations and the need to monitor the ambient and the exterior pipe surface temperature can be eliminated. Barlow's Formula is the common method used to determine hoop stress in the wall of pipe.A. Proposed Procedure The following procedure is proposed to be conducted in association with the current API 1110 pressure testing. F.601. Minimal volume change occurs because a minimal piping deformation occurs therefore. Hoop stress is defined in ASME B31. A failed test can be overlooked because of increased pressure from an increase in the contained substance’s temperature and failed tests may have actually passed due to a temperature decrease.Arthur D Bosshart II TECO Energy reading. The contained substance’s temperature must be measured during testing and an expected pressure change must be calculated from the temperature data and compared to the measured pressure change. By eliminating the need to monitor the external surface temperature of the pipe.601. the effects of hoop stress are negligible. then the energy change of the liquid can be used to determine the temperature change of the pipe eventually determining the thermal expansion of the pipe. The difference between the calculated and the measured pressure values is what must be analyzed. If the temperature change of the contained substance is known. acting circumferentially in a plain perpendicular to the longitudinal axis of the pipe and produced by the pressure of the fluid in the pipe. By monitoring the temperature of the contained substance in the piping during a pressure test.C.

to determine a pass or a fail. F. and set forth below. the deviations. This unaccounted volumetric flow can be compared to Table BPP found in Rule 62-762. Once the testing is completed and all data is gathered.C.e. Temperature of the contained substance should be monitored with the same regularity of the pressure readings. gas).C. if present. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 10 . The next step is to gather referenced data for the known conditions and factors. These include the material of which the pipe being pressure tested is constructed. The test may also be broken into separate calculations if the need to bleed off or increase pressure occurs. The first step is to identify known conditions and factors.. between the theoretical calculated pressure(s) and the actual measured pressure(s) should be analyzed and an unaccounted volumetric flow determined. liquid.Arthur D Bosshart II TECO Energy F.601.A. and the physical state of that contained substance (i. solid. It is important to be aware of the integrity of the temperature probe’s seal to assure that the temperature reading point is not a source of pressure loss. Piping as-built drawing or a process flow diagram (PFD) should be referenced to find the length of pipe that is to be isolated for testing. The pressure test should be performed in accordance with API 1110 monitoring the pressure and ambient temperature. Once the length is determined. This will provide an explanation for such abnormal occurrences while maintaining the accuracy of the test. When the theoretical calculation(s) is complete. the theoretical calculated pressure can be determined. This calculation may be broken into two separate theoretical pressure calculations if circumstances such as those seen in Example #2 occur. Please see Appendix E for a field simplified field method for determining compliance. then the volume of the contained substance can be calculated by using the inside diameter of the pipe. The thermal expansion coefficients of the pipe material and the contained substance must be referenced.A. along with the compressibility of the contained substance. the contained substance within the pipe. but a temperature probe should also be used to take readings of the substance’s temperature contained within the isolated pipe.

it can be determined that the pressure test in Example #1 was a passing test assuming a 1 F temperature change occurred. Calculations were also conducted for Example #2 which was also determined to be a passing pressure test. However. therefore by referencing the Table BPP above it is found that an unaccounted volumetric flow of 0. o Ideal Testing Conditions The proposed additional procedure to API 1110 accounts for temperature change and accurately calculates a volumetric loss from a piping segment that is pressure tested. A full set of calculations of the theoretical pressure for Example #1 is shown in Appendix A. The greatest potential threat to the accuracy of the proposed addition to the API 1110 pressure test method is from the temperature gradients of the contained substance from which temperature readings are being recorded. F. Therefore. there are a few scenarios that could potentially produce an inaccurate result.161469 gallons/hr were unaccounted for during this test. It was determined that 0. Please see Appendix E for a field simplified field method for determining compliance.5 gallons/hr Line segment capacity greater than 100000 gallons Leak Rates for Monthly Testing Leak Rates for Quarterly Testing Leak Rates for Annual Testing 3 gallons/hr 1 gallon/hr 0. An example of one scenario is if a pressure test is performed on an aboveground segment of piping where half is exposed to solar radiation and half Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 11 . it is of the upmost importance to identify ideal testing conditions to optimize the accuracy of the results produced to ensure compliance with Table BPP in Rule 62-762.601.2 gallons/hr 5 gallons/hr 3 gallons/hr 1 gallons/hr Using a spreadsheet developed for this purpose and using data from Example #1.C.A.000 gallons Line Segment Capacity greater than 50000 gallons but less than 100000 gallons 4 gallons/hr 2 gallons/hr 0.000 gallons. Neither of the two examples actually monitored the temperature of the contained substance during testing and therefore these calculated examples are demonstrative only. The pipe segment tested has a capacity less than 50.Arthur D Bosshart II TECO Energy Frequency of Testing Line Segment Capacity Less than 50.2 gallons/hr or less is required to be in compliance.

This would cause the calculations to represent that a greater volumetric loss had occurred and could possibly fail a passing test.5oF ∆T = 2. and heat transfer equations but. Calculations can be conducted from weather data. A failed test could pass because the theoretically calculated pressure would be lowered and would not account for the half of the pipe exposed to the solar radiation. The reverse is true if the temperature measurements were recorded from the cooler half of the pipe. ∆T = 1oF ∆T = 1. then the value of the theoretically calculated pressure will be higher because of a larger temperature change during the pressure test on the half exposed to solar radiation than on the half covered by shade. Temperature Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 12 . If a pipe segment is entirely exposed to direct solar radiation or only exposed to diffused and reflected solar radiation. the energy flow through the pipe to the contained substance on one end will be greater than on the other causing a temperature gradient across the pipe. It is a safe assumption to assume the portion of pipe exposed to solar radiation will absorb more energy than the portion of piping covered by the shade. where a portion of pipe greater than 10% is aboveground and the remaining portion is below ground. If the temperature readings of the contained substance are being measured on the warmer half of the pipe. such piping should be tested during early morning or twilight hours to minimize temperature gradients. solar engineering equations. the proposed procedure would become too complex and could lead to a greater potential for error. the chance for temperature gradients is minimized and testing can be conducted at anytime. Consequently. should be pressure tested separately so potential errors from temperature gradients can be avoided. where portions of piping are exposed to intense day time solar radiation.Arthur D Bosshart II TECO Energy is covered by shade.5oF ∆T = 4oF No Direct Exposure to Solar Radiation Direct Exposure to Solar Radiation To assure accurate results. Piping segments. These temperature gradients are illustrated below.

though linear thermal expansion will have an observable variation.601. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 13 . if this additional procedure is used during API 1110 pressure testing. This proposed method will allow the Department of Environmental Protection (DEP) to have full confidence that. This is an unlikely scenario though during a one hour test. If the pressure test is conducted on above ground piping then the temperature change might be more unstable.C. an accurate grade of pass or fail will be determined in accordance with Table BPP of Rule 62-762. Conclusions The existing API 1110 pressure test method is accurate unless a temperature change in the contained substance occurs. so if a comparison between the volumetric thermal expansion differences between a 4in pipe and a 6in pipe. it might create a larger radial temperature gradient within the 6in pipe and could provide a different end result than the 4in pipe. This proposed method is to be used in conjunction with the API 1110 pressure test method which allows for highly accurate results that account for a temperature change during a test. Volumetric thermal expansion of the piping. at a varying range of temperature change of the pipe material is small to begin with. though highly unlikely. the volume of a contained substance can still be calculated. Outside of the temperature change of the contained substance. at most a 2F to 4F temperature rise. Changing pipe diameters in underground piping is prevalent in older industrial facilities. the difference would be negligible.A. the temperature change of the piping will be very stable. pressure testing should be conducted during early morning or twilight hours and during months where there is not a rapid temperature increase or decrease throughout the day. the volumetric change is what must be noted when measuring pressure. If a large temperature change of the contained substance occurs (more than 5F).Arthur D Bosshart II TECO Energy measurements should be recorded from the middle 20% of the piping segment isolated for testing. F. If the above-mentioned actions are not possible. If the isolated pipe segment is underground. If changes in diameter occur within a piping segment isolated for pressure testing.

TECO Energy.Arthur D Bosshart II TECO Energy Acknowledgements The cooperation and assistance of the members of the Solid Waste Subcommittee of the Florida Electric Power Coordinating Group. Arthur Bosshart. and the Florida Petroleum Council. Randy Melton and Mr. Special thanks to Mr.com Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 14 . Stan Kroh of TECO Energy.A. is greatly appreciated.. Mr. Inc. All queries regarding the proposed method and technical aspects should be directed to Mr. representatives of Marathon Oil. Michael Petrovich of Hopping Green & Sams. adbosshart@tecoenergy. P.

Arthur D Bosshart II TECO Energy Bibliography 1) 2) 3) API Recommended Practice 1110. Fourth Edition.2003 Gas Transmission and Distribution Piping Systems Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 15 . Florida Administrative Code – Draft Rule – September 28. 2007 American Society of Mechanical Engineers (ASME) B31. March 1997 Chapter 62-762.8 .

14*(3.3953 * 1 = 149.3125 in. LTo = 11275.43 * 1 = 4033.Arthur D Bosshart II TECO Energy Appendix Appendix A A calculation walkthrough step-by-step for Example 1: 1) Volumetric Thermal Expansion of Liquid (#2 Diesel Fuel) ∆VL = βL*VLo*∆TL = 0.7674419 -volume is converted to in3 2) Volume of pipe material is calculated π = 3.37884 * 0. density is in pounds per gallon 5) Energy change of the substance from the measured temperature change is calculated Q = ML*CpL*∆TL = 9380* 0. 3) Mass of the pipe is calculated MP = VP*DP = 270.0043) – 1400 = 270. the temperature change of the pipe is determined from the contained substance’s energy change by its temperature change ∆TP = Q/(MP*CpP) = 4033.12) = 3.36954953 = 17680.4 / (17680. The outside radius of the pipe in inches.4681151 gal. density is in pounds per gallon Mass of contained substance ML = DL*VL = 6.3953 in 2 (Referenced Value.30538)*.4681151 * 65.7 * 1400 = 9380 Volume is in gallons.) (The length of pipe in inches at initial temperature) 3 (Value must be converted to in ) Vp = (π*ro *LTo) .VLo (Initial Volume @ Initial Temperature) Vp = (3.583333333 Temperature is given in degrees Fahrenheit 7) Linear Thermal Expansion of Piping (Carbon Steel) Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 16 .30538 3 VLo = 325581.14 ro = 3.4 Energy is given in BTU 6) Rearranging the equation from step 5. 37884 4) Volume is in gallons.00046 * 325581.3125^2)* 11275.

4953 .3166667 hr -0. an adjusted thermal expansion coefficient for the substance is calculated.PAM )*VLo/ ά = ((200.1614693 gallons/hr The answer is given in gallons.03252 * 11275. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 17 .Arthur D Bosshart II TECO Energy ∆Lp = βp* LTo *∆Tp = 0.3953 * 1) = 0.∆VP = 149. ∆VLa = (PTC .6674419 / 325581.30538 * 3. if the initial volume value used in the equation is in gallons From here the unaccounted volume is divided by the testing duration and the number yielded can be compared to the BPP Table to determine compliance.9. The bulk modulus is the inverse of the substances compressibility.6674419 / (325581.1 = 140.325581.3953 = 9.62052 = 325590. Unaccounted volume is found by comparing the difference in pressure changes and rearranging the pressure formula.6674419 The answer is given in cubic inches 11) Using the overall change in volume.21260126 79min /60 = 1.14 * 3.583333333 = 0. The equation below is arranged to use compressibility but further manipulation can form an equation to use the bulk modulus of elasticity “P” coefficient = ∆P = (∆V/VL0) / ά = (140. βA = ∆V / (VLo*∆TL) = 140.1 The volume change is given in cubic inches 10) The overall change in volume accounts for the expansion rates of the substance and the pipe ∆V = ∆VL .21260126 / 1.7674419 .00043205 Answer is given in oF-1 12) The theoretical pressure change is calculated using the bulk modulus of elasticity of the substance.97 – 234) * 1400) / 217500 = -0.3953)* 217500) = 93.3166667 = 0.0000078 * 11275.97 The answer is given in PSI 13) The theoretical calculated pressure is the sum of the theoretical calculated pressure change and the actual measured initial pressure.4953 The volume is given in cubic inches 9) The volume change of the pipe is calculated ∆Vp = VpT2 – VpTo = 325590. This is the volume change with respect to the contained substance.315144785 8) Linear expansion is first calculated then volumetric Volume of the pipe at the final temperature is calculated from its linear thermal expansion VpT2 = πri2LT2 = 3.

625 0.065 6.28 1400 in in in gallons o o Pipe Inside Diameter Pipe Outside Diameter Pipe Schedule Initial Volume of Liquid See Table on Sheet 3 See Table on Sheet 3 See Table on Sheet 3 F F -1 -1 Thermal Expansion Coefficient of Piping Material Thermal Expansion Coefficient of Liquid Compressibility of Liquid o psi BTU/lb F BTU/lb oF BTU/(hr F in) lbs/gallon lbs/gallon o Heat Capacity of Substance in Pipe (Only if Substance is not shown in above List) Heat Capacity of Pipe (Only if Piping Material is not shown in above List) Heat Conductivity (Only if Piping Material is not shown in above List) Density of Substance in Pipe (Only if Substance is not shown in above List) Density of Piping Material (Only if Piping Material is not shown in above List) This is the calculation portion of the spread sheet: Theoretical Pressure Change with Bulk Elastic Properties of Diesel Compressibility ∆P = (∆VL2/VL0) * ά ά = Compressibility (#2 Diesel) ∆P = Change in Pressure ά ∆P ∆VL = βL*VLo*∆TL ∆VL = Change in Volume of Liquid βL = Thermal Expansion Coefficient of Liquid 217500 93. The spread sheet shows entries made for analyzing Example #1.Arthur D Bosshart II TECO Energy Appendix B The following spreadsheet was used for developing the proposed method and for calculation purposes. Data entry section of the spread sheet: Select Pipe Material Carbon Steel 0.97 psi psi Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 18 .5% C Input Field Calculated Field (DO NOT EDIT) Enter Data if Selections are not Found in List Testing Conditions and Data Collected Drop Down List Auto populated if selection is on list Select Substance contained in Pipe #2 Diesel Fuel Oil Pretest Data 6.

62052 325590.583333333 0.0000078 11275.Arthur D Bosshart II TECO Energy VLo = Initial Liquid Volume ∆TL = Change in Temperature βL VLo ∆TL ∆VL 0.3953 in in3 Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 19 .1 in3 11275. ro Ape 3.4484 in in2 Volumetric Thermal Expansion of Piping (Carbon Steel) ∆Lp = βp* LTo *∆Tp βp = Thermal Expansion Coefficient of Piping Material LTo = Length of Pipe @ Initial Temperature ∆Tp = Change in Piping Temperature βp LTo ∆Tp 0.60878 Use heat transfer Equation ft F ∆Lp VpTo = πri2LTo in *assuming no residual air pockets in pipe VpTo = Volume of Pipe @ Initial Temperature ri = radius of inside piping diameter ri VpTo VpT2 = πri2LT2 VpT2 = Volume of Pipe @ Final Temperature LT2 = Length of Pipe @ Final Temperature LT2 VpT2 ∆Vp = VpT2 – VpTo ∆Vp = Change in Piping Volume ∆VP 9.4953 in in3 3.3125 234623.0325 325581.30538 3.315144785 o F -1 in o 939.3953 1 149.00046 325581.5581395 in3 Pipe Surface Area Ape = 2πro2 + 2πroLTo Ape = Surface Area of Pipe Exterior ro = Radius of Pipe Exterior *assume that the minimal increase in piping surface due to temperature rise has no effect on heat transfer from the pipe exterior surface to the liquid contained within the pipe. Therefore. piping surface area at initial temperature is used for calculation.7674419 o F -1 in3 o F 232.

1 in^3 = .Arthur D Bosshart II TECO Energy Overall Change in Volume ∆V = ∆VL .6674419 in3 270.583333333 BTU/lb o F o 140.4681151 65.PAM )*VLo/ ά ∆VLa = Calculated Volume Difference associated with pressure change PTC = Theoretical Calculated Pressure PAM = Actually Measured Pressure Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 20 .4 BTU/lb o F BTU F This is your results portion of the spread sheet: Unaccounted Volume ∆VLa = (PTC .36954953 17680.43 4033.12 3.0043 gallons 1 kg/m^3 = .∆VP ∆V = Overall Change in Volume ∆V Mass of Piping MP= DP*VP ML = Mass of Isolated Piping DL = Density of Piping Material VP DP MP Mass of Substance in Pipe ML = DL*VL MP = Mass of Substance contained in Pipe DP = Density of Substance contained in Pipe VL DL ML Energy in Substance Q=ML*CpL*∆TL Q = Heat CpL = Heat capacity of Substance CpL Q Temperature Change of Pipe ∆TP = Q/(MP*CpP) CpP = Heat Capacity of Pipe Material CpP ∆TP 0.008345404 lbs/gallon 1400 6.7 9380 gallons lbs/gallon lbs.37884 gallons lbs/gallon lbs. 0.

21260126 Appendix C Assumptions 1) A minimal increase in piping surface due to temperature rise has no effect on heat transfer from the pipe exterior surface to the liquid contained within the pipe. and during normal testing conditions an extreme temperature change will not occur over single test duration. 4) The radial temperature gradient of the pipe material is negligible because pipe walls are less than . Therefore. piping surface area at initial temperature is used for calculation.Arthur D Bosshart II TECO Energy PTC ∆VLa 200.6 in.97 psi gallons ∆VLa /hr 0. Appendix D Nomenclature ά = Compressibility (#2 Diesel) ∆P = Change in Pressure ∆VL = Change in Volume of Liquid βL = Thermal Expansion Coefficient of Liquid VLo = Initial Liquid Volume ∆TL = Change in Temperature Ape = Surface Area of Pipe Exterior Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 21 . 2) The system to be tested is assumed to be comprised entirely of a homogeneous liquid. No volume change occurs because no deformation of the piping material occurs. 3) Hoop Stress on piping does not cause piping deformation because pressure levels used during testing are well below the design pressure of the piping system.1614693 gallons/hr -0.

1 F change in temperature within a perfectly isolated volume. The “P” Coefficient is found by relating compressibility to a change in volume and defining a change in temperature between the initial temperature (Ti) and the final temperature (T f) to be . This 9.4 PSI occurs for every .1 F. Using equations 1 through 12 found in Appendix A of “Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance” and defining referenced coefficients for liquid o o Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 22 .Arthur D Bosshart II TECO Energy ro = Radius of Pipe Exterior βp = Thermal Expansion Coefficient of Piping Material LTo = Length of Pipe @ Initial Temperature ∆Tp = Change in Piping Temperature VpTo = Volume of Pipe @ Initial Temperature ri = radius of inside piping diameter VpT2 = Volume of Pipe @ Final Temperature LT2 = Length of Pipe @ Final Temperature ∆Vp = Change in Piping Volume ∆V = Overall Change in Volume ML = Mass of Isolated Piping DL = Density of Piping Material MP = Mass of Substance contained in Pipe DP = Density of Substance contained in Pipe Q = Heat CpL = Heat capacity of Substance CpP = Heat Capacity of Pipe Material Appendix E Simplified Field Method For #2 Diesel it is found that a linear pressure change of 9.4 PSI change per unit of temperature will be known as the “P” coefficient in the pressure testing packet in appendix I.

4 PSI occurs for every .Arthur D Bosshart II TECO Energy compressibility. piping thermal expansion.4(MF) During the test. PTc = Pi + 9.A. (4) Using the piping volume that was o calculated prior to testing. APT is the allowable pressure difference between the theoretically calculated pressure (P Tc) and the actually measured pressure (Pam).4 PSI and then added to the initially measured pressure (Pi) from the beginning of the test to determine the theoretically calculated pressure (PTc). pipe heat capacity. APT = ((∆VLa/hr)(ά))/VLo APT = PTc . the noted temperature change during the testing period should be divided by . The Allowable Pressure Tolerance (APT) is calculated by defining an acceptable volumetric loss which for purposes of compliance in Florida is defined to be . and liquid heat capacity the “P” coefficient for any substance may be found.2 gallons/hour (∆VLa/hr) by Table BPP within 62-762 F.1 F change in temperature. pipe density. liquid thermal expansion.C. Equation 1 is the formula used for calculating ATP where compressibility (ά) and piping volume at the initial temperature are shown (V Lo). the APT lookup table must be present. the lower limit of the actually measured Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 23 . By subtracting the APT defined for the given piping volume from the PTc. Determine the size of piping and the schedule of piping then find the inside radius of the pipe using reference material. Calculate the volume within the section of pipe that is to be isolated for pressure testing using the following equation: VTo = πr L o 2 (1) (2) (3) Given that 9.Pam Procedure Simplified Find as-built drawings of piping system to be pressure tested and note the lengths of each section that is to be isolated. the APT can be found using the APT lookup table.1 F to determine the magnitude factor to be used later. When the pressure testing is complete the magnitude factor (MF) should be multiplied by 9. liquid density. See Equation 4.

2 0.75 20. Appendix F APT Lookup Table 9.25 33.25 34.2 0.64 18.99 15.75 93.2 0.59 13.13 17.75 20.89 24.08 11.2 Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 24 .79 12.2 0.36 10.2 0.83 38.73 16.2 0.95 12.21 28.50 62.59 8.83 14.2 0.61 43.77 18.2 0.00 27.2 0.30 21.17 23.82 8.38 36.84 36.50 65.39 19.50 14.00 14.2 0.56 72.38 49.59 13.54 15.2 0.45 11.97 60.17 ∆VLa /hr 0.46 31.50 108.2 0.99 16.05 20.17 22.31 15.19 25.54 15.75 hr APT (PSI) 65.75 18.59 24.2 0.63 31.61 40.07 29.1 ∆ F Piping Volume (Gal.2 0.66 27.96 7.50 40.2 0.2 0.73 16.78 36.2 0.20 9.08 11.2 0.2 0.2 0.19 25.42 18.4 PSI / .15 10.68 67.32 9.17 16.54 14.07 29.31 41.39 19.12 Test Duration 1.03 13.19 25.42 54.2 0.52 10.2 0.59 13.63 29.) 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 o Test Duration .16 7.2 0.13 17.94 13.2 0.60 9.06 8.43 12.66 28.55 36.14 54.19 26.2 0.50 21.11 15.25 54.34 32.99 30.64 22.75 20.88 10.25 33.5 APT (PSI) 130.10 23.75 21.55 12.54 15.05 12.2 0.2 0.37 27.25 59.48 15.63 77.38 48.91 20.62 27.71 19.64 17.26 12.89 21.70 14.21 81.77 19.25 32.33 43.66 21.2 0.25 10.2 0.10 24.2 0.2 0.14 19.50 39.38 46.2 0.31 15.31 13.54 16.25 hr APT (PSI) 108.88 10.13 17.78 38.10 25.38 50. If the measured pressure during the duration of a pressure test falls below this defined lower limit then the test fails.19 18.00 72.2 0.77 7.76 11.40 16.43 45.2 0.75 90.2 0.13 17.91 18.2 0.32 54.98 31.37 8.65 Test Duration 1.65 11.2 0.19 46.72 23.18 12.91 15.59 Test Duration 1 hr APT (PSI) 87.Arthur D Bosshart II TECO Energy pressure can be defined.10 14.2 0.17 16.89 9.30 22.19 18.61 10.18 13.

08 11.41 7.2 0.00 100.88 8.00 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Piping Volume (Gallons) Appendix H Simplified Field Method Sample Calculation For example.Arthur D Bosshart II TECO Energy 4400 4500 4600 4700 4800 4900 5000 7.25 7.33 11.57 11. The volume of the pipe that is to be isolated was calculated to have a capacity of 1400 gallons. Test Duration 1.75 hrs.06 8.88 13. Test Duration 60.05 0.89 9.88 14.00 0. Before the test it was determined that the pipe was 6in.18 13.94 6.2 0.59 13.00 20.67 9.2 0.80 6.83 14.2 0. an underground pipe that contains #2 diesel fuel is pressure tested in the state of Florida.2 0.00 .26 9.46 9.00 40.66 6.50 14.36 12.82 11. in diameter and had a schedule 40 wall thickness.53 9.25 hrs.32 13.5 hrs.70 12.2 0.09 6.00 Allowable Pressure Tolerance "APT" (PSI) 80.10 10.2 Appendix G Compliance Curve Compliance Curve #2 Diesel APT = ((∆VLa /hr)*ά) / VLo 120. Test Duration 1 hr. Test Duration 1. The line was properly packed and the initial temperature and pressure readings Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 25 .

4 PSI occurs for every .1 F = 11 Next. the allowable pressure tolerance (APT) is 46. the lower limit for compliance is determined.4 PSI – 46.1 F change in temperature within a perfectly isolated volume therefore the magnitude factor (MF) is first calculated. Next.4 PSI(11) = 203. See Appendix J to view the completed Line Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 26 .79 PSI The final temperature reading from the test was 171 PSI. PTc = Pi + 9. The test lasted 1. o o o o MF = (71.61 PSI = 156.1 F .5 hours and the final temperature and pressure readings were 71. The magnitude factor has no units. The final reading is greater than the lower limit therefore the pressure test passes. Pressure Testing form using this example. we find that for a piping system of 1400 gallons.4 PSI Using the APT lookup table.4(MF) = 100 PSI + 9.70 F)/. the theoretically calculated pressure (PTc) is determined. Lower Limit = 203.1 F and 171 PSI respectively.61 PSI. Is the piping system in compliance? o o Using the simplified procedure we know that a linear pressure change of 9.Arthur D Bosshart II TECO Energy were 70 F and 100PSI respectively.

Use the Facility Identified Isolated Piping Segment Capacity found on line 1 and the test duration found on line 8 to determine the APT value. Line 12 -. for example. divide 90 by 60 to convert the test duration to hours. Line 13 – Determine the lower limit value by subtracting line 11 from line 12. Line 11 – Determine the theoretically calculated pressure by multiplying the value from line P by line 10 and adding the product of the multiplication to the initial pressure reading on line 2. Line 3 – Enter the initial temperature reading once testing begins into line 3.” Meaning the piping segment must be completely filled with the contained substance with no vapor or air pockets. in hours. Test Data Before the first temperature and pressure readings are recorded. Please reference for proper packing procedures section 3. Line 4 – Enter the time which testing begins into line 4. The lower limit is the limit that that the pressure cannot drop below during testing to be compliant.1 and enter it into Line 10. Line 5 – When testing is complete enter the final pressure reading into line 5. Enter this value into line 12. enter the initial pressure reading once testing begins into line 2. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 27 . Line 1 -.The facility representative should identify an accurate pipe capacity through calculation or best engineering judgment. Line 6 – Enter the final temperature reading into Line 6. the piping segment being pressure tested must be properly “packed. Enter this value into line 13. March 1997. Information regarding the pipe capacity and the contained substance should be given to the entity or individuals conducting the pressure test prior to testing. Enter this value into line 11. into line 8. Enter this value into line P. Line 10 – Divide the value from line 9 by 0. If a test.Arthur D Bosshart II TECO Energy Appendix I Line Pressure Testing Packet Instructions Pretest Pretest data should be acquired prior to pressure testing.5hrs.Values for the allowable pressure tolerance “APT” may be found on page 3 of the DEP Line Pressure Testing Packet in the APT Lookup Table. Line 9 – Subtract line 6 from line 3 and enter the change in temperature into line 9. Line 2 – After the line is properly packed and pressurized the desired test pressure. If this value is a negative number. lasts 90 minutes. Line 7 – Enter the time which the test ended into line 7. then simply multiple the value by -1 and enter the positive number into line 9.7 of API Recommended Practice 1110 Fourth Edition. which in this example is 1. Line P – Values for the “P” coefficient may be found on page 2 of the DEP Line Pressure Testing Packet in the “P” Coefficient Lookup Table. Post Test Calculation Line 8 – Subtract line 7 from line 4 and enter the length of the test.

less than the final pressure (P F) reading. on line 13. March 1997” Initial Test Data Initial Pressure Reading (Pi) “units of pressure must be given in PSI” “units of Temperature must be given in oF” ____________________________ ____________________________ ____________________________ Final Test Data (2) (3) (4) (5) (6) Initial Temperature Reading (Ti) Time Began Final Pressure Reading (PF) “units of pressure must be given in PSI” ____________________________ ____________________________ Final Temperature Reading (TF) Time Ended Post Test Calculation Test Duration (t) “units of time must be given in hours” “units of Temperature must be given in oF” ____________________________ (7) t = line 7 – line 4 = __________________________ Hours ∆T = line 6 – line 3 = __________________________ F MF = line 9 / 0. find the associated APT value.1 F = ____________________________ PTc = line 2 + line P x line 10 = _________________ F APT = _____________________________________ PSI o o o (8) (9) (10) (11) (12) (13) Temperature Change (∆T) “units of Temperature must be given in oF” Magnitude Factor (MF) “The Magnitude Factor is unit less”” Theoretically Calculated Pressure (PTc) “units of Temperature must be given in oF” Allowable Pressure Tolerance (APT) “units of Pressure must be given in PSI” The APT is found using the table on page 3 of the pressure testing packet. on line 13. otherwise circle the compliance determination of PASS. PASS Pressure Test Conducted by Pressure Test Technician Technician Signature Facility Representative Facility Representative Signature FAIL _____________________________________ _____________________________________ _____________________________________ _____________________________________ _____________________________________ Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 28 . on line 5 then circle the compliance determination of FAIL. is greater than the final pressure (PF) reading.7 of API Recommended Practice 1110 Fourth Edition.Arthur D Bosshart II TECO Energy DEP Line Pressure Testing Worksheet Facility Owner _______________________ Facility Name _______________________ Line Segment Tested _______________________ Pretest Data Data Description Contained Substance Date Facility ID _________________ _________________ Line Number Data Entry ____________________ P=_________________________ ___________________________ Y N P (1) The “P” coefficients can be found using a referenced value of the contained substance found on page 2 of the pressure testing packet. on (14) line 5? Y N Test Result If the lower limit pressure (Lower Limit). Facility Identified Isolated Piping Segment Capacity (V) Capacity must be given in gallons Test Data Is the test segment properly packed? “For proper line packing procedures refer to Section 3. Using the “Facility Identified Isolated Piping Segment Capacity” on line (1). Lower Limit “units of Pressure must be given in PSI” Lower Limit = line 11 – line 12 = __________________ PSI Is the lower limit pressure (Lower Limit).

Arthur D Bosshart II TECO Energy “P” Coefficient Lookup Table Enter the correct “P” coefficient into the DEP Line Pressure Testing Worksheet into “line P” Gasoline #2 Diesel Biodiesel #6 Fuel Oil Benzene Methanol Ethanol 9.4 Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 29 .

00 217.73 16.55 12.13 17.39 19.59 8.48 15.70 14.2 0.25 59.37 27.25 34.73 16.13 17.00 14.2 0.98 31.19 18.4 PSI / .36 10.63 77.05 20.00 72.66 27.00 27.59 13.13 17.33 43.91 18.2 0.50 14.07 29.99 30.31 15.2 0.2 0.2 0.46 Test Duration 1.46 31.83 14.10 23.36 12.13 108.50 14.65 12.2 0.16 7.2 0.34 32.25 163.21 81.25 33.18 13.2 0.99 15.94 13.88 10.75 93.50 326.54 15.19 18.2 0.18 ∆VLa /hr 0.2 0.54 15.) 100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700 1800 1900 2000 2100 2200 2300 2400 2500 2600 2700 2800 2900 3000 3100 3200 3300 3400 3500 3600 3700 3800 3900 4000 4100 4200 4300 4400 4500 4600 Test Duration .2 0.2 0.50 65.17 16.2 0.2 0.77 7.38 36.75 20.82 8.1 ∆oF Piping Volume (Gal.2 0.2 0.42 54.89 9.30 22.31 15.25 7.2 0.2 0.50 163.2 Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 30 .2 0.17 23.11 15.75 18.83 38.2 0.62 27.25 32.2 0.2 0.79 12.30 21.75 21.75 81.94 108.2 0.96 7.50 62.40 16.64 22.17 16.61 43.38 50.2 0.15 10.14 54.25 10.89 24.18 12.14 19.2 0.54 15.59 24.2 0.75 20.25 135.2 0.89 21.95 12.32 54.10 25.00 108.39 19.12 9.75 90.08 11.43 45.91 20.2 0.38 49.2 0.5 APT (PSI) 652.66 21.68 67.50 21.19 25.25 33.10 24.88 181.19 25.26 12.88 10.19 46.59 7.09 Test Duration 1 hr APT (PSI) 435.2 0.59 13.75 hr APT (PSI) 326.89 9.77 19.21 28.83 14.60 9.38 46.2 0.19 26.76 11.50 39.45 11.2 0.99 16.38 48.2 0.63 29.20 9.2 0.75 20.2 0.52 10.55 36.50 108.31 13.37 8.91 15.61 40.2 0.13 17.Arthur D Bosshart II TECO Energy APT Lookup Table #2 Diesel Fuel Oil 9.43 12.2 0.17 14.61 10.64 18.75 87.66 28.50 145.2 0.19 25.97 60.77 18.25 hr APT (PSI) 543.50 40.17 22.82 Test Duration 1.54 14.25 54.42 18.72 23.67 9.25 217.06 8.07 29.13 130.2 0.56 72.78 36.59 13.32 9.2 0.2 0.41 7.65 11.2 0.03 13.54 16.84 36.56 65.71 19.08 11.08 11.10 14.63 31.2 0.78 38.31 41.75 271.05 12.64 17.2 0.

78 4.79 3.59 13.73 4.47 3.53 4.50 7.2 0.17 7.40 6.94 6.72 5.2 0.41 4.55 3.70 8.70 10.2 0.37 5.04 5.97 6.2 0.06 8.52 10.88 7.57 11.86 11.2 0.46 10.43 3.11 6.2 0.02 6.25 7.02 4.88 13.2 0.80 6.55 12.88 5.10 10.91 7.65 5.87 6.06 7.66 7.37 8.25 7.47 4.12 8.45 7.58 5.2 0.2 0.67 3.2 0.2 0.13 6.40 9.47 8.55 6.37 8.24 8.2 0.26 10.26 8.24 5.71 6.74 9.84 3.2 0.05 12.Arthur D Bosshart II TECO Energy 4700 4800 4900 5000 5100 5200 5300 5400 5500 5600 5700 5800 5900 6000 6100 6200 6300 6400 6500 6600 6700 6800 6900 7000 7100 7200 7300 7400 7500 7600 7700 7800 7900 8000 8100 8200 8300 8400 8500 8600 8700 8800 8900 9000 9100 9200 9300 9400 9500 9600 6.71 9.2 0.44 5.88 6.2 0.30 6.91 8.80 6.2 0.30 5.94 8.88 10.2 0.66 10.04 9.2 0.80 0.27 6.94 4.98 5.65 11.89 4.2 0.93 3.06 8.53 6.66 6.2 0.2 0.06 6.2 0.68 4.63 4.96 5.77 7.2 0.59 6.68 7.32 9.08 11.2 0.35 7.2 0.2 0.58 4.29 4.26 9.88 8.22 9.35 4.53 5.54 9.51 5.2 0.2 0.2 0.25 7.2 0.16 6.88 3.91 5.63 3.03 3.50 7.46 9.88 10.80 5.2 0.63 8.70 8.66 13.25 11.59 3.21 6.12 5.53 11.96 7.19 9.25 6.93 5.13 7.90 6.89 9.78 5.85 5.77 7.69 6.2 0.31 12.79 12.09 7.2 0.36 10.60 4.63 5.00 4.2 0.51 3.49 6.2 0.20 10.63 6.21 8.80 4.2 0.06 10.77 7.2 Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 31 .06 5.83 5.94 4.2 0.2 0.60 9.2 0.50 8.35 5.2 0.77 8.72 5.44 5.2 0.59 8.55 7.86 7.82 8.32 13.2 0.98 3.83 4.80 6.26 5.00 7.45 11.2 0.04 5.53 8.04 5.47 6.18 4.33 7.63 7.41 7.13 4.89 9.06 8.37 8.94 6.18 5.15 7.16 8.07 9.18 6.2 0.08 4.37 7.33 11.18 5.73 4.71 3.2 0.2 0.2 0.87 4.2 0.2 0.59 7.72 5.06 7.40 6.66 4.75 3.40 6.32 6.10 5.24 4.02 6.38 9.

48 4. Test Duration 1.53 0.49 5. Test Duration 1.44 6.36 3.61 5.25 hrs.00 100.39 4.00 .00 0 500 1000 1500 2000 2500 3000 3500 4000 4500 5000 Piping Volume (Gallons) Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 32 .00 Allowable Pressure Tolerance "APT" (PSI) 80.Arthur D Bosshart II TECO Energy 9700 9800 9900 10000 3.5 hrs.33 3.2 0.2 0.30 3.00 0. Test Duration 60.44 4.55 5.2 Compliance Curve #2 Diesel APT = ((∆VLa /hr)*ά) / VLo 120.2 0.00 40. Test Duration 1 hr.73 6.00 20.59 6.35 5.26 4.66 6.75 hrs.

Arthur D Bosshart II TECO Energy Appendix J Completed Line Pressure Testing Worksheet Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 33 .

must be in pounds per gallon) VLo = 1400 gal. Subtracts the outside volume if pipe was a solid cylinder from the inside capacity of the pipe.4681151 gal.7 * 1400 = 9380 lbs. Must be in gallons) ML = DL*VL = 6. 5) Energy change of the substance from the measured temperature change is calculated. (Initial volume @ the initial temperature. In the example below.36954953 lbs. We are using a 6 in.00046 * 325581.14*(3.4 PSI occurs for every .1 F. Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 34 .4681151 * 65. (From Equation 2) MP = VP*DP = 270. For #2 Diesel it is found that a linear pressure change of 9./gal (Referenced Coefficient.36954953 = 17680. must be in pounds per gallon) VP = 270.3125 in. 4) Mass of contained substance This is calculated to determine energy transfer. DP = 65. LTo = 11275.3953 in (Value must be converted to in ) o o ∆TL = Tf – Ti = . 37884 lbs.Arthur D Bosshart II TECO Energy Appendix K Step-by-Step Calculation of the “P” Coefficient The “P” Coefficient is found by relating compressibility to a change in volume and defining a change in temperature between the initial temperature (Ti) and the final temperature (Tf) to be o o .30538 3 VLo = 325581.97674419 in 2) Volume of pipe material is calculated This is not the capacity of the pipe.VLo (Initial Volume @ Initial Temperature) Vp = (3./gal (Referenced Coefficient.3953 in 2 3 3 (Referenced Value.7 lbs.14 ro = 3. Answer must be given in gallons.1 F) ∆VL = βL*VLo*∆TL = 0.) (The length of pipe in inches at initial temperature) 3 (Value must be converted to in ) Vp = (π*ro *LTo) .0043) – 1400 = 270.1 F change in temperature within a perfectly isolated volume.3953 * .3125^2)* 11275.00046 F (Referenced coefficient. π = 3. 3) Mass of the pipe is calculated The mass must be calculated to determine energy transfer. must be in F ) 3 3 VLo = 325581. pipe. 1) Volumetric Thermal Expansion of Liquid (#2 Diesel Fuel) This is the change in volume due to the change in temperature. The outside radius of the pipe in inches. DL = 6. This is the amount of piping material in in .1 = 14. This calculation is independent of the amount of volume but requires an initial value for volume to begin the calculation of the “P” coefficient. o -1 o -1 βL = .30538)*.4681151 gal. we will use the capacity of one of our actual piping systems.1 F (Define your temperature change as .

30538 * .325581. ∆VL = 14. Must be in “BTU/lb. F (Referenced Coefficient.0315144785 in. 8) Volume of the pipe at the final temperature is calculated from its thermal expansion This is used to determine the overall change in volume with respect to all thermal expansions affecting the isolated system.0325 in. (Referenced Value.1 F (Define your temperature change as .1 = 403.14 * 3. ML = 9380 lbs. (The length of pipe in inches at initial temperature) o ∆Tp = .3953 = 0. The inside radius of the pipe in inches.0315144785 in.043 BTU/lb.3053 .91 in 3 (From Equation 1) (From Equation 9) Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 35 . must be in F ) LTo = 11275.34 / (17680.3583333333 F (From Equation 6) ∆Lp = βp* LTo *∆Tp = 0. (From Equation 3) ∆TP = Q/(MP*CpP) = 403.3583333333 = 0. o -1 o -1 βp = .) LTo = 11275. F”) o o ∆TL = Tf – Ti = .43 * .34 BTU (From Equation 6) o o CpP = .3053 in (From Equation 8) 3 3 VLo = 325581.3953 in (Value must be converted to in ) ∆Vp = VpT2 – VLo = 325582. F (Referenced Coefficient.0000078 * 11275.Arthur D Bosshart II TECO Energy This is calculated to determine energy transfer from the pipe material to determine the temperature change of the pipe material and eventually determine the thermal expansion of the pipe. Must be in “BTU/lb.97674419 in 3 ∆VP = .30538 + .3053 in 9) The volume change of the pipe is calculated This is the volume change of the pipe due to thermal expansion.14 ri = 3. π = 3.37884 lbs.30538 (The length of pipe in inches at initial temperature) ∆Lp = 0. (From Equation 7) VpT2 = π*ri (LTo ∆Lp) = 3. 3 VpT2 = 325582. F”) MP = 17680.34 BTU 6) Temperature Change of Piping Material Rearranging the equation from step 5. Q = 403.0000078 F (Referenced coefficient. the temperature change of the pipe is determined from the contained substance’s energy change by its temperature change.91 in 10) 3 2* + 2 3 o The overall change in volume accounts for the expansion rates of the substance and the pipe.12 BTU/lb.3583333333 F 7) Thermal Expansion of Piping (Carbon Steel) The Thermal Expansion will not substantially vary from material to material and therefore will not affect the determined value of the “P” Coefficient.1 F) Q = ML*CpL*∆TL = 9380* 0. The differences from material to material are negligible.315144785) = 325582.12) = . (From Equation 4) o o CpL = .37884 * 0.0325 * (11275.30538 in.

Compressibility must be in psi) “P” coefficient = ∆P = (∆V/VL0) / ά = (14.397 psi Appendix L Step-by-Step Calculation of a Specific APT Value The Allowable Pressure Tolerance (APT) is calculated by defining an acceptable volumetric loss which for purposes of compliance in Florida is defined to be .C.5 hrs.2 gal/hr ά = 217500 psi VLo = 1400 gal.5 = 46.91 = 14.61 psi Effects of Temperature Change on Pressure Testing and Maintaining Environmental Compliance 36 .06674419 in 12) Determination of the “P” Coefficient. 3 The theoretical pressure change is calculated using the bulk modulus of elasticity of the substance.06674419 in (From Equation 11) 3 3 VL0 = 325581. between the theoretically calculated pressure (PTc) and the actually measured pressure (Pam).2 * 217500)/1400)*1.A.3953) * 217500) = 9.∆VP = 14. 1) APT = (((∆VLa/hr)(ά))/VLo)*t ∆VLa/hr = 0.Arthur D Bosshart II TECO Energy ∆V = ∆VL . t = 1. defined by an environmental authority. We will use the referenced and calculated values from Appendix K. APT is the allowable pressure difference. (This is the minimal accepted leak rate defined by environmental authority) (Compressibility of #2 Diesel) (Value must be in Gallons) (Duration of test.97674419 . Equation 1 is the formula used for calculating ATP where compressibility (ά) and piping volume at the initial temperature (VLo) are accounted used in determination.2 gallons/hour (∆V La/hr) by Table BPP within 62-762 F. The equation below can be arranged to use compressibility or the bulk modulus of elasticity.3953 in (Value must be converted to in ) ά = 217500 psi (Referenced Coefficient.0. given in hours) APT = (((∆VLa/hr)(ά))/VLo)*t = ((0. The bulk modulus is the inverse of the substances compressibility. 3 ∆V = 14.06674419 / 325581.