Testing and Evaluation of New Low

Transcription

Research Investigation on the Testing and
Evaluation of New Low Emission Fixed
Maximum Liquid Level Gauges for Use in
LP-Gas Containers
Final Report
By
Rodney L. Osborne
Battelle Memorial Institute
Ronald R Czischke
Underwriters Laboratories
Prepared for
Propane Education & Research Council
1140 Connecticut Ave. NW, Suite 1075
Washington, DC 20036
PERC Docket 15198
Battelle Project N007298
September 2009
Battelle Notice
Battelle does not engage in research for advertising, sales promotion, or
endorsement of our clients' interests including raising investment capital or
recommending investments decisions, or other publicity purposes, or for any use
in litigation.
Battelle endeavors at all times to produce work of the highest quality, consistent
with our contract commitments. However, because of the research and/or
experimental nature of this work the client undertakes the sole responsibility for
the consequence of any use or misuse of, or inability to use, any information,
apparatus, process or result obtained from Battelle, and Battelle, its employees,
officers, or Directors have no legal liability for the accuracy, adequacy, or
efficacy thereof.
UL Research Investigation Notice
It should be understood that the results of this investigation apply only to the
particular samples submitted for testing. The test results indicated in this report
are not intended to imply Listing, Classification, or other Recognition of any
product or materials.
The Classification Marking or Listing Mark of Underwriters Laboratories Inc. on
the product is the only method provided by Underwriters Laboratories Inc. to
identify products that have been produced under its Classification or Listing and
Follow-Up Service.
In no event shall Underwriters Laboratories Inc. be responsible to anyone for
whatever use or nonuse is made of the information contained in this Report and in
no event shall Underwriters Laboratories Inc., its employees, or its agents incur
any obligation or liability for damages, including, but not limited to,
consequential damages, arising out of or in connection with the use, or inability to
use, the information contained in this Report.
EXECUTIVE SUMMARY
To address the emissions from the fixed maximum liquid level gauges* (FMLLG) used in LPGas † containers, some vendors in the propane industry have developed low emission units with
orifice diameters that are reduced compared to the standard orifice gauge (nominally a 54-drill
size, or 0.055 inch). While the smaller orifice does indeed reduce the amount of propane vapor or
liquid passing through the unit, there are concerns that the orifices may be more susceptible to
blockages from particulate contaminants or from ice crystals formed during the expansion
process through the orifice.
The Propane Education & Research Council issued a Request for Proposal (RFP) to consider
these issues. This report is the culmination of a research project that addressed the issues of that
RFP as a joint effort by Battelle and Underwriters Laboratories (UL).
The objective of this research project was to compare the fluid flow rate through a current
standard No. 54 drill size (0.055 inch) orifice FMLLG to two new designs of smaller-orifice
gauges, and to evaluate these smaller-orifice gauges with respect to the susceptibility to blocked
flow due to ice crystals or obstructions.
This objective was accomplished by the conduct of three separate series of tests:
•
Test 1 – Air Flow Capacity Tests
•
Test 2 – Liquid Propane Release and Freeze Susceptibility Tests
•
Test 3 – Susceptibility to Clogging by Particulates Tests
Battelle provided overall coordination and technical support for the project while Underwriters
Laboratories acquired the necessary samples, equipment, and supplies and performed the
required tests and gathered the original data.
Sample Selection
While the bodies of gauges may differ, and the screw assembly may have different geometries,
all FMLLG are essentially the same; i.e. a body with an orifice, a screw assembly, with a seat
disc, and usually a dip tube. These elements are shown in Figure ES-1.
This research project anticipated the testing of three samples each of the three FMLLG designs,
(nine total) using one representative dip tube length. Six of the samples were identical except for
the orifice size as noted below:
•
Three samples had a standard orifice of a No. 54 drill size (0.0550 inch)
•
Three samples had a reduced orifice of a No. 72 drill size (0.0250 inch)
*
Also referred to as spitter valve, outage gauge, or ullage gauge.
† The terms “LP-Gas” and “propane” are used interchangeably in this report.
Emission FMLLG, Docket 15198
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The final three samples, identified as “self-cleaning design,” had a modified screw assembly that
incorporated a fluted drill rod in the seating area as shown in Figure ES2, with a body orifice of
approximately 0.047 inch (1.19 mm). The manufacturer has claimed that the fluted drill rod
reduced the area of the orifice to an effective area approximately equal to that of a No. 72 drill
size (0.0250 inch).
The dip tube length was kept constant for this project. All nine samples had a dip tube length of
5.0 inches measured from the end of the body, and an inside diameter of 0.124 inch (3.15 mm).
This length was considered representative.
Test 1 – Vapor Emission Comparison – Air Flow Capacity Tests
During the container filling process, an FMLLG will initially vent propane vapor until the
propane liquid level reaches the end of the dip tube. Therefore, it is appropriate to measure the
amount of propane vapor released for the various designs of the gauge. Rather than use propane
vapor directly we chose to perform airflow capacity tests and convert the results to propane
vapor for comparison purposes. This approach and the test method utilized are very similar to
the methods in UL standards covering flow capacity tests for LP-Gas devices such as regulators
and relief valves in vapor service. Flow capacity tests were conducted with air at three pressures
representing propane vapor temperatures of 0 F, 50 F, and 100 F, which corresponded to propane
container pressures of 20, 80, and 175 psig. These results were converted to propane vapor using
industry accepted practices in order to obtain a base line propane vapor release rate at the various
pressures.
During the testing at 175-psig-inlet pressure, sample Nos. 7 and 9 became difficult to open
because the seat disc was becoming dislodged from the screw assembly, as shown in Figure ES3.
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Figure ES-1. Representative FMLLG: the dip tube (left); close-up view of screw assembly
(top, right); close-up view of seat disk in body (bottom, right).
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Figure ES-2. “Self-cleaning” FMLLG sample units.
Figure ES-3. Seat disk shown dislodged on self-cleaning FMLLG (three units at left).
The screw assemblies for the self-cleaning design samples exhibited variations in manufacturing
tolerance, as shown by the six samples on the right in the photo above, which played a role in the
variability of the data collected.
For the air flow tests, the flow through the 72-drill size orifice gauge was 72 percent to
76 percent less than the flow through the 54-drill size orifice for the 20, 80, and 175-psig inlet
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pressures. The self-cleaning gauge had a flow reduction of 65 to 69 percent on the flows through
the 54-drill size orifice for the 20 psig and 80 psig inlet pressures. The self-cleaning design gave
erratic results at the highest test pressure of 175 psig.
Test 2 – Liquid Propane Release and Freeze Susceptibility Tests
Once the container liquid level reaches the end of the dip tube of a FMLLG, the gauge will vent
propane liquid. It is appropriate to measure this liquid release at this point. The liquid propane is
flashing to vapor at the outlet of the gauge. There are concerns that because of moisture found in
propane, these new smaller orifice gauges may freeze and therefore not indicate that the proper
filling level is reached. For the second series of tests, gauge samples were installed in LP-Gas
containers, the containers were filled with propane saturated with water, and the gauge samples
were fully opened to release liquid propane for 60 seconds, during which time observations were
made for freeze-ups. The containers were weighed before and after the release to measure the
amount of liquid propane released.
During the testing at the 100 F test temperature, sample Nos. 7 and 9 became difficult to open
because the seat disc was becoming dislodged from the screw assembly. Sample 8 did not have
the problem to the same degree.
The difficulty in opening the screw assembly for sample Nos. 7 and 9 at the 100 F test
temperature contributed to the variability of the data for that sample set. No comment about the
reduction in liquid propane can be made because of the scatter of data measured.
Even with the operational problems with the two samples at the 100 F test temperature, at no
time, at any of the test temperatures, was freezing at the orifice observed for all nine samples
tested.
For the liquid propane flow tests, the flow through the 72-drill size orifice gauge was 58 percent
to 60 percent less than the flow through the 54-drill size orifice for the 0 F, 50 F, and 100 F
propane temperatures. The self-cleaning gauge had a flow reduction of 69 to 78 percent on the
flows through the 54-drill size orifice for the 0 and 50 F tests. The self-cleaning design gave
erratic results at the 100 F test condition.
Test 3 – Susceptibility to Clogging Test
As propane may contain particulate matter, there was concern that smaller-sized orifices in
FMLLGs might become clogged with debris and therefore not indicate the proper filling level at
the correct time frame. For this third series of tests, samples were installed into a suitable
pressure vessel piping system initially filled with clean water. Tests were conducted at inlet
pressures of 20 psig and 175 psig, and the water collected into a discharge container over time in
order to determine a mass flow rate. This test also provided a base line liquid flow rate
measurement for each sample. The water was then replaced with a water/polystyrene latex
spheres solution. The range of sizes and concentration of polystyrene latex spheres was based
upon particulate and solids in propane information and data generated from the PERC-funded
study on solids in propane, Final Report on Water and Solid Contaminant Control in LP Gas,
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Docket 11353 * , and the maximum residual matter found in commercial propane in accordance
with ASTM D1835 † . The test was re-conducted using the water/polystyrene latex spheres
solution in order to ascertain if the smaller orifice designs were susceptible to clogging and to
compare the liquid flow to the existing orifice size design (No. 54 drill size).
The results of the water and water/microsphere solution test indicate that the 72-drill size orifice
and the self-cleaning design gauges do reduce liquid flow rates when compared to the standard
54-drill size orifice.
Operational problems persisted with the self-cleaning design but not to the same degree as with
the other tests.
At no time was clogging observed in either of the two small orifice designs at both test pressures.
*
Battelle, 2006. Final Report on Water and Solid Contaminant Control in LP Gas, Docket 11353, for the Propane
Education and Research Council, Washington, D.C.
†
ASTM, 2005. ASTM D 1835-05 (2005), Standard Specification for Liquefied Petroleum (LP) Gases), American
Society for Testing and Materials, West Conshohocken, PA.
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Table of Contents
Page
Executive Summary ....................................................................................................................... iii Sample Selection......................................................................................................................... iii Test 1 – Vapor Emission Comparison - Flow Capacity Tests with Air ..................................... iv Test 2 – Liquid Propane Release and Susceptibility to Freezing Test....................................... vii Test 3 – Susceptibility to Clogging Test.................................................................................... vii Background and Introduction ......................................................................................................... 1 Objective ......................................................................................................................................... 1 Technical Plan and Approach ......................................................................................................... 2 Task 1A. Sample Selection from Commercially Available Gauges............................................ 2 Task 1B. Test Method Development ........................................................................................... 6 Test 1 – Vapor Emission Comparison - Flow Capacity Tests with Air.................................... 6 Test 2 – Liquid Propane Release and Susceptibility to Freezing.............................................. 6 Test 3 – Susceptibility to Clogging Tests: ................................................................................ 7 Task 1C. Test Rig Construction................................................................................................... 7 Test 1 – Vapor Emission Comparison - Flow Capacity Tests with Air.................................... 7 Test 2 – Liquid Propane Release and Susceptibility to Freezing.............................................. 8 Test 3 – Susceptibility to Clogging Tests ............................................................................... 11 Task 2. Testing of FMLLG Sample ........................................................................................... 13 Test 1 – Vapor Emission Comparison - Flow Capacity Tests with Air.................................. 13 Test Sequence ...................................................................................................................... 13 Results for Task 2, Test 1 .................................................................................................... 14 Findings at 20 psig inlet Pressure ........................................................................................ 17 Findings at 80 psig Inlet Pressure ........................................................................................ 18 Findings at 175 psig Inlet Pressure: ..................................................................................... 18 Test 2 – Liquid Propane Release and Susceptibility to Freezing Test.................................... 18 Test Sequence ...................................................................................................................... 18 Method Used to Calculate Amount of Water to Be Placed in Each Container ................... 19 Method Used to Calculate Filling Density of the Containers for This Test ........................ 19 Results for Task 2, Test 2 .................................................................................................... 20 Findings at 0 F Test Temperature ........................................................................................ 22 Findings at 50 F Test Temperature ...................................................................................... 24 Findings at 100 F Test Temperature: ................................................................................... 25 Test 3 – Susceptibility to Clogging Tests ............................................................................... 26 Test Sequence ...................................................................................................................... 26 Method for Determining Concentration Level for a Water/Polystyrene Latex Microsphere
Solution ................................................................................................................................ 27 Results for Task 2, Test 3 .................................................................................................... 28 Conclusions ................................................................................................................................... 32 References ..................................................................................................................................... 33 Testing and Evaluation of New Low
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List of Tables
Page
Table 1. Air Flow Test Results for FMLLG Designs at Different Upstream Pressures and Pipe
Pressures. .................................................................................................................... 14 Table 2. Air Flow Test Results Converted to Propane Vapor Flow Rates. .............................. 17 Table 3. Air Flow Rates Converted to Propane Vapor Flow Rates – Flow Reductions. .......... 18 Table 4. Liquid Propane Release Test – Temperature = 0 F..................................................... 20 Table 5. Liquid Propane Release Test – Temperature = 50 F................................................... 21 Table 6. Liquid Propane Release Test – Temperature = 100 F................................................. 21 Table 7. Liquid Propane Release Flow Rates - Flow Reduction. ............................................. 26 Table 8. Results of Clogging Tests: Flow Rate Through FMLLG Using Water at Specified
Pressures. .................................................................................................................... 28 Table 9. Results of Clogging Tests: Flow Rate Through FMLLG Using Water/Microspheres at
Specified Pressures. .................................................................................................... 29 Table 10. Results of Clogging Tests: Comparison of Flow Rates Using Water and Flow Rates
Using Water/Microsphere Solution. ........................................................................... 30 List of Figures
Figure ES-1. Representative FMLLG: the dip tube (left); close-up view of screw assembly
(top, right); close-up view of seat disk in body (bottom, right). ........................... v Figure ES-2. “Self-cleaning” FMLLG sample units. ................................................................ vi Figure ES-3. Seat disk shown dislodged on self-cleaning FMLLG (three units at left)............ vi Figure 1. Cross-section of FMLLG.............................................................................................. 3 Figure 2. Representative FMLLG, with dip tube ......................................................................... 3 Figure 3. Representative FMLLG: the dip tube (left); close-up view of screw assembly (top,
right); close-up view of seat disk in body (bottom, right). .................................... 4 Figure 4. Self-cleaning FMLLG ................................................................................................. 5 Figure 5. Views of the Flow Capacity Test Rig........................................................................... 8 Figure 6. Special 5-lb propane container. .................................................................................... 9 Figure 7. Propane supply tank and insulated containers. ............................................................. 9 Figure 8. Propane supply tank and pump. .................................................................................... 9 Figure 9. Propane pump, special container, and scale. .............................................................. 10 Figure 10. Environmental chamber. ......................................................................................... 10 Figure 11. Reweighing tank. ................................................................................................... 11 Figure 12. Views of the PVC pipe container............................................................................ 12 Figure 13. Self-cleaning FMLLGs, with dislodged seat disk on three samples on left. .......... 15 Figure 14. Photographs of liquid propane release tests for 54-drill, 72-drill, and self-cleaning
gauges. ................................................................................................................. 23 Figure 15. Photographs of liquid propane release tests for 54-drill, 72-drill, and self-cleaning
gauges. ................................................................................................................. 24 Figure 16. Photographs of liquid propane release tests for 54-drill, 72-drill, and self-cleaning
gauges. ................................................................................................................. 25 Figure 17. Clogging test – representative result. ...................................................................... 31 Testing and Evaluation of New Low
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BACKGROUND AND INTRODUCTION
Regulatory agencies, including state, federal, and international bodies, are continuing to address
climate change by establishing comprehensive policies. The policies generally have three
components:
•
Slowing the growth of emissions, including combustion and fugitive sources
•
Strengthening science, technology and institutions
•
Enhancing international cooperation.
Propane * transfer operations have been identified as a potential source of fugitive emissions. The
global warming potential (GWP) of propane is three to ten times higher than carbon dioxide.
Even though the total amounts of propane emissions are substantially smaller than those for CO2
and other gases, the reduction of propane emissions is a concern of the propane industry.
Propane emission reduction is part of the National Propane Gas Association’s Strategic Plan
[NPGA 2007]. A study prepared for the Western Propane Gas Association [LP–Gas 2007]
considered the sources of propane emissions. The study estimates that approximately 85 percent
of all propane fugitive emissions result from the use of fixed maximum liquid level gauges †
(FMLLG) on portable DOT cylinders ranging in capacity from 4 lb to 40 lb of propane, 20- to
43-lb propane lift truck cylinders, customer stationary ASME storage tanks, and bobtail tanks.
To address the emissions from these FMLLG, some vendors in the propane industry have
developed low emission units with reduced orifice diameters. While the smaller orifice does
indeed reduce the amount of propane vapor or liquid passing through the unit, there are concerns
that the orifices may be more susceptible to blockages from particulate contaminants or from ice
crystals formed during the expansion process through the orifice.
The Propane Education & Research Council issued a Request for Proposal (RFP) to consider
these issues. This report is the culmination of a research project that addressed the issues of that
RFP, and was a joint effort by Battelle and Underwriters Laboratory (UL).
OBJECTIVE
The objective of this research project was to compare the fluid flow rate through the current
standard No. 54 drill size (0.055 inch) orifice fixed maximum liquid level gauges (FMLLG) to
two new designs of smaller-orifice gauges and to evaluate these smaller-orifice gauges, with
respect to the susceptibility to blocked flow due to ice crystals or obstructions.
This objective was accomplished by the conduct of three separate tests:
•
*
†
Air Flow Capacity Tests
The terms “LP-Gas” and “propane” are used interchangeably in this report.
Also referred to as spitter valve, outage gauge, or ullage gauge.
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•
Liquid Propane Release and Freeze Susceptibility Tests
•
Susceptibility to Clogging by Particulates Tests
TECHNICAL PLAN AND APPROACH
Battelle provided overall coordination and technical support for the project while Underwriters
Laboratories acquired the necessary samples, equipment, and supplies and performed the
required tests and gathered the original data.
In order to achieve the objectives of this project, the following tasks were identified:
Task 1A. Sample selection from commercially available gauges
Task 1B. Test method development
Task 1C. Test rig construction
Task 2. Testing of FMLLG (for fluid flow rates and susceptibility to blockages)
Test Series 1: Vapor Emission Comparison – Air Flow Capacity Tests
Test Series 2: Liquid Propane Release and Freeze Susceptibility Tests
Test Series 3: Susceptibility to Clogging Tests
These tasks are described in further detail below.
Task 1A. Sample Selection from Commercially Available Gauges
Several views of a typical fixed maximum liquid level gauge are shown below in Figures 1
through 3.
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Figure 1. Cross-section of FMLLG
Figure 2. Representative FMLLG, with dip tube
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Figure 3. Representative FMLLG: the dip tube (left); close-up view of screw assembly
(top, right); close-up view of seat disk in body (bottom, right).
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The bodies of gauges may differ, and the screw assembly may have different geometries, but all
FMLLGs are essentially the same; i.e., a body with an orifice, a screw assembly, with a seat disc,
and usually a dip tube. The gauge can be installed into a container as a separate device, or as
part of a shutoff, or multiple purpose valve, or manifold assembly. In most cases they contain a
dip tube, but if the valve body is installed at the proper filling level, the dip tube is not needed.
As mandated by NFPA 58, 2008 Edition [NFPA 2008], paragraph 5.7.5.10, the orifice of the
gauge shall not exceed a No. 54 drill size (0.0550 inch). Most FMLLGs in service have this
orifice diameter. Dip tube lengths vary by the type and size of the container to which the gauge
is installed. As noted in Table 5.7.3.2 of NFPA 58-2008, dip tube lengths can vary from 2.2
inches to 7.0 inches for portable cylinders. Large containers, such as a DOT 420 lb size
container, would require a dip tube with a length of about 11 inches.
This research project anticipated the testing of three samples each of the three FMLLG designs, a
total of nine samples, using one representative dip tube length.
Six of the samples were identical except for the orifice size as noted below:
Three samples had a standard orifice of a No. 54 drill size (0.0550 inch).
Three samples had a reduced orifice of a No. 72 drill size (0.0250 inch).
The final three samples, identified as “self-cleaning design,” had a modified screw assembly that
incorporated a fluted drill rod in the seating area as shown below, with a body orifice of
approximately 0.047 inch (1.19 mm). The manufacturer claimed that the fluted drill rod reduced
the area of the orifice to an effective area approximately equal to that of a No. 72 drill size
(0.0250 inch).
Figure 4.
Self-cleaning FMLLG
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The dip tube length was kept constant for this project. All nine samples had a dip tube length of
5.0 inches measured from the end of the body, and an inside diameter of 0.124 inch (3.15 mm).
This length was considered representative.
Task 1B. Test Method Development
Test Series 1 – Vapor Emission Comparison - Air Flow Capacity Tests
During a container filling process, an FMLLG will initially vent propane vapor until the propane
liquid level reaches the end of the dip tube. Therefore, it is appropriate to measure the amount of
propane vapor released for the various designs of gauges. Rather than use propane vapor directly
we chose to perform airflow capacity tests and convert the results to propane vapor for
comparison purposes. This approach and the test method utilized are very similar to the methods
in UL standards covering flow capacity tests for LP-Gas devices such as regulators and relief
valves in vapor service. Flow capacity tests were conducted with air at three pressures
representing propane vapor temperatures of 0 F, 50 F, and 100 F, which corresponded to propane
container pressures of 20, 80, and 175 psig). These results were converted to propane vapor
using industry accepted practices in order to obtain a base line propane vapor release rate at the
various pressures. The conversion from one gas to another is accomplished by multiplying the
flow of one gas by the square root of the ratio of their specific gravities. Each test sample was
placed in a suitable pressure-containing segment with pressure measurement capability, and
connected to an air supply system incorporating a regulator, control valve, and flowmeter. The
pressure to the sample was held constant while the flow rate through the sample was measured.
A total of 27 tests were planned and carried out; (3 pressures times 9 samples = 27 total tests).
Test Series 2 – Liquid Propane Release and Freeze Susceptibility Tests
Also during a container filling process, FMLLG will vent propane liquid when the propane
liquid level reaches the end of the dip tube. It is appropriate to measure this liquid release at this
point. The liquid propane is flashing to vapor at the outlet of the gauge. There are concerns that
because of moisture found in propane, that these new smaller orifice gauges might freeze up and
therefore not indicate that the proper filling level is reached. For the second series of tests,
appropriate sized LP-Gas containers were obtained, with two openings (one for a shutoff valve
for which to fill, and a second opening into which was installed each test sample. Water and a
pure grade of propane (purity level = 99%) were used.
Enough de-ionized water was put into each container to saturate the propane with water, which
represented a worst case scenario. Each container was then filled with pure grade propane to
ensure that only propane and water were present in the container. The fill level of each container
was such to ensure only liquid propane was released from the FMLLG sample. Each filled
container assembly was initially weighed. This test was also conducted with the samples and
containers conditioned at three temperatures, of 0 F, 50 F, and 100 F; for a time frame long
enough to ensure the propane and container assembly were at these test temperatures. Then the
FMLLG sample was fully opened to release liquid propane into the air for no longer than 60
seconds, during which time, the outlet was visually observed for freezing. If freezing occurred
before 60 seconds, the time until freeze up was noted. At the conclusion of the release, the
sample was closed and the container was re-weighed. Care was taken to ensure that any frost
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that accumulates on the outside of the container was removed before re-weighing occurred. The
change of weight per unit time provided the amount of liquid propane released. A total of 27
tests were planned and carried out (3 samples times 3 designs times 1 dip-tube times
3 temperatures = 27 tests).
Test Series 3 – Susceptibility to Clogging Tests
As propane may contain particulate matter, there was concern that smaller-sized orifices in
FMLLGs might become clogged with debris and therefore not indicate the proper filling level at
the correct time. For this third series of tests, each sample was installed into a suitable pressure
vessel piping system initially filled with clean water. The piping system was connected to a
pressure supply system incorporating a regulator, and control valve. Water was allowed to flow
through each sample FMLLG at 20 psig and 175 psig, and collected into a discharge container
over time in order to determine a mass flow rate. This test series was only conducted at the
minimum and maximum pressures from the other test series because if clogging were to occur, it
would be worse case at one of these pressures. Each test was conducted for two minutes to
minimize the human error of opening and closing the gauge screw assembly. This portion
provided a bases line liquid flow rate measurement for each sample.
The test was stopped and the water was replaced with a water/polystyrene latex spheres solution.
The range of sizes and concentration of polystyrene latex spheres was based upon particulate and
solids in propane information and data generated from the PERC-funded study on solids in
propane, Final Report on Water and Solid Contaminant Control in LP Gas, Docket 11353 and
the maximum residual matter found in commercial propane in accordance with ASTM D1835.
The test was re-conducted using the water/polystyrene latex spheres solution in order to ascertain
if the smaller orifice designs were susceptible to clogging and to compare the liquid flow to the
existing orifice size design (No. 54 drill size). A total of 36 tests were planned and carried out,
(3 samples times 3 designs times 2 pressures times 2 solutions = 36 tests).
Task 1C. Test Rig Construction
Test Series 1 – Vapor Emission Comparison - Air Flow Capacity Tests
For this test sequence a piping arrangement was constructed that included a 4-inch NPT pipe
assembly to represent a container, with a pressure tap in the sidewall of the pipe for which to
measure flow test pressure, a piping manifold system that included an air supply system of
adequate capacity, a regulator, control valves, upstream pressure measuring devices, and three
flow meters, as shown in Figure 5. Each sample was individually installed into the end of the 4inch pipe assembly.
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Figure 5. Views of the Flow Capacity Test Rig.
For this test phase special 5-lb containers, containers of propane, a hand pump, large insulated
containers, water, and a sufficient quantity of antifreeze solution to use at the 0 F test
temperature were used (Figures 6 to 9). We utilized UL’s large walk-in conditioning chamber
(Figure 10) and two weight scales, with the final weight scale having an accuracy of 0.2g (Figure
11).
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Figure 7. Propane supply tank, 5-lb cylinders and
insulated liquid bath coolers.
Figure 6. Special 5-lb propane
container.
Figure 8.
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Propane supply tank and pump.
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Figure 9. Propane pump, special container, and scale.
Figure 10. Environmental
chamber.
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Figure 11. Reweighing tank.
Test 3 – Susceptibility to Clogging Tests
For the final test sequence a piping arrangement was constructed that included a 2-inch NPT
PVC pipe assembly to represent a container (Figure 12), with a pressure tap in the sidewall of the
pipe for which to measure flow test pressure, a shutoff valve a flexible hose connector and a
large pressurized reservoir that contained the water and water/micros sphere solution. The
reservoir was pressurized using a regulator and compressed nitrogen supply. Each sample was
individually installed into the end of the 4-inch pipe assembly. Microspheres were purchased in
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three sizes, 11, 85, and 222 micrometers. The microspheres were added to the water by
calibrated pipettes.
Figure 12. Views of the PVC pipe container.
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Task 2. Testing of FMLLG Samples
Test Series 1 – Vapor Emission Comparison – Air Flow Capacity Tests
Test Sequence
An airflow piping system was assembled to include air supply regulator, flow-meter manifold
and a 4-inch pipe assembly that includes a coupling for a pressure indicator and a bushing in
which each sample was installed. The 4-inch pipe assembly provided an internal volume similar
to a small LP-Gas container, which was considered adequate for comparing gaseous flow
through the different samples. The flow meter manifold included three branch lines; each one
having a shutoff valve, upstream air flow temperature indicator, upstream pressure indicator and
mass flow meter followed by a second shutoff valve so that each branch line could be isolated.
The three flow meters provided a reading in volumetric units corrected to standard conditions
with the following ranges:
Flow meter No. 1 0-10 SLPM
Flow meter No. 2 0-50 SLPM
Flow meter No. 3 0-180 SLPM.
A plug was installed into the end of the 4-inch pipe assembly and the entire piping arrangement
was pressurized with air to the highest test pressure in static condition as measured at the 4-inch
pipe sidewall tap. During this step, care was taken to not exceed each flow meter maximum flow
rate. A leak test was performed at all fitting joints. Afterwards the pressure was slowly released
and care was taken to not exceed each flow meter maximum flow rate.
One gauge sample was installed at a time into the end of 4-inch pipe assembly
With the sample in a closed position, air pressure was slowly applied to the system using the
system regulator and using the leg in the manifold with the largest flow rate meter (0-180 SLPM)
until the 4-inch pipe assembly with sample was at the first test pressure in static condition as
measured at the 4-inch pipe sidewall tap. During this step, care was taken to not exceed flow
meter maximum flow rate. Upstream air temperature was measured to ensure that test conditions
were within the flow meter’s specifications and calibration tolerances.
Each sample had its thumbscrew opened two complete turns, which was considered full open
position. Air supply regulator was adjusted as necessary to bring the air pressure at the 4-inch
pipe assembly to the test pressure in a flowing condition.
If the flow rate was within the flow rate of one of the other two flow meters, the active pressure
leg shutoff valve was closed and other valve opened to allow flow in the correct range flow
meter leg. The pressure and flow rate was stabilized for at least 30 seconds. Upstream pressure,
upstream air temperature, flow meter number and flow rate were recorded on the data sheet.
13
Battelle
The upstream shutoff valve was then closed and the pressure was allowed to decay to
atmospheric pressure. The sample was removed from the 4-inch pipe assembly and the next
sample was installed in the pipe assembly.
The procedure was followed for all nine samples. This procedure was then repeated for the other
two test pressures. A total of 27 tests were conducted (i.e., three samples each of three designs,
each at three test pressures [20 psig, 80 psig, and 175 psig] = 3 times 3 times 3 = 27 tests).
Results for Task 2, Test Series 1
The data collected are shown in Table 1.
Table 1.
FMLLG
Design
Air Flow Test Results for FMLLG Designs at Different Upstream Pressures and
Pipe Pressures.
Sample
No.
Upstream
Temp.
(°F)
Air Flow Rate (L/Min)
Flow
Meter
No.
Reading
at 70 °F
Corrected
to 60 °F
Avg. at
60 °F
Std
Dev
Temp Corr
Factor
28.0
0.1
0.9811
Test Series at Upstream Pressure 20 psig, Pipe Pressure 20 psig
54 drill
size
72 drill
size
Self
cleaning
design
1
75
2
28.6
28.1
2
75
2
28.5
28.0
0.9811
3
74
2
28.5
28.0
0.9811
4*
76
1
7.9
7.8
5
76
1
7.7
7.6
0.9811
6
76
1
8.1
7.9
0.9811
7*
75
2
12.1
11.9
7.8
9.9
0.2
3.7
0.9811
0.9811
8
75
1
5.7
5.6
0.9811
9*
75
2
12.5
12.3
0.9811
54 drill
size
72 drill
size
Self
cleaning
design
1
73
3
85.8
84.2
2
72
3
85.2
83.6
0.9811
3
71
3
84.9
83.3
0.9811
4*
73
2
21.0
20.6
5
73
2
20.2
19.8
0.9811
6
73
2
21.0
20.6
0.9811
7*
72
2
22.8
22.4
8
72
2
18.9
18.5
0.9811
9*
72
2
36.3
35.6
0.9811
14
83.7
20.3
25.5
0.4
0.5
9.0
0.9811
0.9811
0.9811
Battelle
FMLLG
Design
Sample
No.
Upstream
Temp.
(°F)
Flow
Meter
No.
Reading
at 70 °F
Corrected
to 60 °F
Avg. at
60 °F
Std
Dev
Temp Corr
Factor
166.0
1.8
0.9811
54 drill
size
72 drill
size
Self
cleaning
design
1
73
3
171.0
167.8
2
71
3
169.2
166.0
0.9811
3
69
3
167.4
164.2
0.9811
4*
74
2
43.6
42.8
5
74
2
41.7
40.9
0.9811
6
73
2
43.6
42.8
0.9811
7*
73
3
133.2
130.7
8
75
2
42.2
41.4
0.9811
9*
73
3
75.6
74.2
0.9811
42.2
82.1
1.1
45.2
0.9811
0.9811
This test sequence was conducted after the liquid propane release test. During that testing at
100 F test temperature, sample Nos. 7 and 9 became difficult to open because the seat disc was
becoming dislodged from the screw assembly (Figure 13). The screw assembly was replaced on
these two samples for this airflow test. The asterisk denotes that the screw assembly was
replaced for that sample.
Figure 13. Self-cleaning FMLLGs, with dislodged seat disk on three samples on left.
Screw assemblies from the left were; from sample 7, from sample 7A (screw assembly replaced
again), and sample 9, respectively. The other six screw assemblies on the right show the
variation in manufacturing tolerance, which played a role in the variability of the data collected
for this design.
During this testing, sample No. 4 screw assembly became hard to turn, so the screw assembly on
that sample was replaced. The asterisk in the spreadsheet above for sample No. 4 also reflects
the screw assembly replacement.
15
Battelle
To convert the overall average airflow rate for each set of samples to an average propane vapor
flow rate, the following formula was used:
Propane Vapor Flow Rate = (Airflow rate) divided by (square root of propane specific gravity)
A factor of 0.81 was used in Table 2.
16
Battelle
Table 2.
Air Flow Test Results Converted to Propane Vapor Flow Rates.
FMLLG
Design
Sample No.
Reading at 70
°F
Corrected to 60 °F
Ave. at 60 °F
Calc. Ave. Propane
Vapor (L/Min) at 60 F
28.0
22.7
7.8
6.3
9.9
8.0
83.7
67.8
20.3
16.5
25.5
20.7
166.0
134.5
42.2
34.2
82.1
66.5
Test Series With Inlet Pressure to Sample 20 psig
54 drill size
72 drill size
Self cleaning
design
1
28.6
28.1
2
28.5
28.0
3
28.5
28.0
4*
7.9
7.8
5
7.7
7.6
6
8.1
7.9
7*
12.1
11.9
8
5.7
5.6
9*
12.5
12.3
54 drill size
72 drill size
Self cleaning
design
1
85.8
84.2
2
85.2
83.6
3
84.9
83.3
4*
21.0
20.6
5
20.2
19.8
6
21.0
20.6
7*
22.8
22.4
8
18.9
18.5
9*
36.3
35.6
54 drill size
72 drill size
Self cleaning
design
1
171.0
167.8
2
169.2
166.0
3
167.4
164.2
4*
43.6
42.8
5
41.7
40.9
6
43.6
42.8
7*
133.2
130.7
8
42.2
41.4
9*
75.6
74.2
Findings at 20 psig inlet Pressure
The 72-drill size orifice gauge had an approximate reduction of 72% in the amount of vapor
released over the standard 54-drill size orifice gauge.
17
Battelle
At this low pressure the self-cleaning design gauge operated as intended and had an approximate
reduction of 65% in the amount of vapor released over the standard 54-drill size orifice gauge.
Findings at 80 psig Inlet Pressure
At this intermediate pressure the self-cleaning design gauge operated as intended and had an
approximate reduction of 69% in the amount of vapor released over the standard 54-drill size
orifice gauge.
Findings at 175 psig Inlet Pressure:
Given the operation issues of the self-cleaning design at this high pressure, it is not appropriate
to provide an estimate in reduction of vapor because of the large variability of the data set.
These findings are summarized in Table 3.
Table 3.
Air Flow Rates Converted to Propane Vapor Flow Rates – Flow Reductions.
Air Test
FMLLG Inlet
Pressure
54-Drill Flow
Rate
72-Drill Flow Rate Æ Flow
Reduction from 54-Drill Flow
Self-Cleaning Flow Rate Æ Flow
20 psig
22.7 liter/min
6.3 liter/min Æ 72%
8.0 liter/min Æ 65 %
80 psig
67.8 liter/min
175 psig
134 liter.min
NA Æ NA
Test Sequence
This test sequence was conducted first and consisted of three series of tests, with each series
using the same nine special 5-lb containers and nine gauge samples (three pieces of three
FMLLG designs). Therefore 27 total tests were conducted. The three series were conducted
using liquid propane at temperatures of 0 F, 50 F, and 100 F.
Each FMLLG sample was installed into one opening of each container. A service valve to allow
for filling and emptying the container was installed in the other opening. After installing a gauge
sample and service valve into each container, each empty container was labeled for sample
identification and weighed to determine its tare weight.
A 100-lb cylinder of CP grade propane (minimum purity level of 99 mole %) was conditioned in
an environmental chamber for a minimum of 8 hours, in order to bring the liquid propane to the
appropriate test temperature. In addition, two liquid baths, each in a portable insulated cooler,
were also placed in the environmental chamber so that the baths were at the same test
18
Battelle
temperature as the chamber. Each cooler was large enough to hold a single 5 lb propane
container. The nine empty cylinders and hand pump were pre-conditioned before filling began.
An amount of 2.0 ml of distilled water was placed into each 5-lb container. The amount of water
added to each container was based upon the worst case saturation level of propane. The water
was added to each container at room temperature immediately before the next step.
Method Used to Calculate Amount of Water to Be Placed in Each Container
Water solubility in liquid propane increases with temperature. At 32 F water solubility is
0.006% by weight; and at 100°F, it is 0.049% by weight. By using the largest solubility figure
(0.00049) times the largest fill weight, (5.58 lbs) would equal 1.24 ml of water to be added as a
worse case. 2.0 ml of water was added to each container at each temperature to ensure the
propane liquid was saturated with water. Extra water would settle to the bottom of the container
and not affect the test results.
Using a hand pump, hoses, and suitable fittings, an amount of liquid propane, as noted under
Results for each test temperature, was transferred from the 100 lb supply cylinder into each 5 lb.
container. The amount of liquid propane put into each container represented approximately 85%
of the total capacity of the container. This amount along with the 5.0-inch length dip tube
connected to each sample gauge ensured that only liquid propane was released. After filling,
each container was immediately weighed. The transfer process and initial weighing were
performed outdoors at ambient temperature. Then each container, was weighed a second time on
a more precise scale indoors, and then was immediately put back into the environmental chamber
for sufficient time to bring the temperature of the liquid propane back to appropriate test
temperature.
Method Used to Calculate Filling Density of the Containers for This Test
Each 5-lb container had a water capacity of 11.9 lbs. 11.9 divided by the density of water (62.4
lbs/ft3) = 0.1907 ft3 (= 5.4 Liters) total volume. 0.1907 times 85 % = 0.162 ft3 (4.6 Liters). This
will be the target fill volume. Multiplying the target fill volume by the density of propane at
each temperature will give the target fill weight for each test. We put in a range for each fill
volume as noted to correct for “rounding” errors.
Each 5-lb container was put into a liquid bath maintained at same temperature as the
environmental chamber, and then taken outdoors in the cooler for the release test. By keeping
the 5-lb container in the liquid bath, constant test temperature was maintained, which was
unaffected by ambient air temperature. The thumbscrew on the FMLLG sample was opened
approximately two complete turns, which allowed liquid propane to be released into the air for
no longer than 60 seconds, during which time, the outlet was visually observed for freezing. At
the instant of opening the thumbscrew, the timer was started.
If freezing occurred before 60 seconds, the time until freeze up was recorded. At the conclusion
of the release, which was not longer than 60 seconds, the sample was closed, and the timer
stopped. The container was then taken indoors, removed from the liquid bath, dried, and then reweighed using the same scale that was used for filling. Care was taken to ensure that any frost or
19
Battelle
moisture that accumulated on the outside of the container was removed before re-weighing
occurred. The change of weight per unit time provided the rate of liquid propane released.
After each container was re-weighed, the container was taken to a safe location and the complete
liquid contents released, by opening the service valve. After the first test was conducted at a
sample temperature of 0 F, the test sequence was repeated with the environmental chamber,
liquid bath and samples at a test temperatures of 50 F, and then lastly at 100 F.
Results for Task 2, Test Series 2
Tables 4, 5, and 6 show the results recorded for the liquid propane release test at temperatures of
0 F, 50 F, and 100 F, respectively.
Table 4.
Sample
Liquid Propane Release Test – Temperature = 0 F.
Propane
in Tank,
lbs
Amount
of Liquid,
% Filled
Propane
Release
Time, s
85.5
88.5
86.5
Liquid Release Rate,
g/min
Bath
Temp, F
Propane
Released,
grams
Measured
Average
Std. Dev.
60
62
61
0
5
0
307.7
367.3
409.6
307.70
355.45
402.89
355.3
47.6
148.5
12.2
79.2
11.4
FMLLG Design: 54 Drill
1
2
3
5.63
5.83
5.70
4
5.68
86.2
61
0
159.6
156.98
5
5.66
85.9
61
-1
156.7
154.13
6
5.74
87.1
64
-2
143.5
134.53
61
-2
93.9
92.36
FMLLG Design: Self-Cleaning
7
5.70
86.5
8
5.61
85.2
61
-2
72.6
71.41
9
5.60
85.0
61
-2
75.2
73.97
20
Battelle
Table 5.
Sample
Liquid Propane Release Test – Temperature = 50 F.
Propane
in Tank,
lbs
Amount
of Liquid,
% Filled
Propane
Release
Time, s
86.5
87.2
87.3
g/min
Bath
Temp, F
Propane
Released,
grams
Measured
Average
Std. Dev.
61
61
61
51
49
49
535.3
532.1
490.0
526.5
523.4
482.0
510.6
24.9
203.6
11.3
157.3
31.5
1
2
3
5.32
5.36
5.37
4
5.33
86.7
61
49
205.1
201.7
5
5.28
85.9
61
49
196.5
193.3
6
5.33
86.7
61
49
219.3
215.7
7
5.33
86.7
61
49
196.5
193.3
8
5.39
87.7
61
49
136.8
134.6
9
5.35
87.0
61
49
146.6
144.2
Table 6.
Sample
Liquid Propane Release Test – Temperature = 100 F
Propane
in Tank,
lbs
Amount
of Liquid,
% Filled
Propane
Release
Time, s
86.2
86.9
86.2
g/min
Bath
Temp, F
Propane
Released,
grams
Measured
Average
Std. Dev.
61
61
61
100
100
100
726.2
684.3
682.7
714.3
673.1
671.5
686.3
24.3
275.0
27.2
190.0
48.2
1
2
3
4.86
4.90
4.86
4
4.91
87.0
61
99
249.6
245.5
5
4.83
85.6
61
100
285.2
280.5
6
4.90
86.9
61
100
304.1
299.1
60
100
238.2
238.2
7*
4.88
86.5
8
4.85
86.0
60
100
141.9
141.9
9†
4.87
86.3
60
99
189.9
189.9
* Upon turning the thumb-screw, the vent valve did not open immediately - had to open an additional two turns for a
total of three turns.
† Upon turning the thumb-screw, the vent valve did not open immediately - had to open an additional two turns for a
total of three turns.
This test sequence was conducted first. During the testing at the 100 F test temperature, sample
Nos. 7 and 9 became difficult to open because the seat disc was becoming dislodged from the
screw assembly. Sample 8 did not have the problem to the same degree. We were not able to
investigate the problem until the test was completed and the container emptied and the samples
21
Battelle
removed. Figure 13 above under the Air Flow Test Results shows the dislodging of the seat
discs on the self-cleaning samples.
The difficulty in opening the screw assembly for sample Nos. 7 and 9 at the 100 F test
temperature contributed to the variability of the data for that sample set. No comment about the
reduction in liquid propane can be made because of the scatter of data measured.
Even with the operational problems with the two samples at the 100 F test temperature, at no
time, at any of the test temperatures, was freezing at the orifice observed for all nine samples
tested.
Findings at 0 F Test Temperature
The 72-drill size orifice gauge had an approximate reduction of 58% in the amount of liquid
propane released over the standard 54-drill size orifice gauge.
At this low temperature the self-cleaning design gauge operated as intended and had an
approximate reduction of 78% in the amount of liquid propane released over the standard 54-drill
size orifice gauge.
Photos of the propane releases are shown in Figure 14.
22
Battelle
54-Drill Release Test at 0 F
Self-Cleaning Release Test at 0 F
Figure 14. Photographs of liquid propane release tests for 54-drill, 72-drill, and selfcleaning gauges.
23
Battelle
The 72-drill size orifice gauge had an approximate reduction of 60% in the amount of liquid
propane released over the standard 54-drill size orifice gauge. At this intermediate test
temperature, the self-cleaning design gauge had an approximate reduction of 69% in the amount
of vapor released over the standard 54-drill size orifice gauge. Photos of the propane releases are
shown in Figure 15.
24
Battelle
released over the standard 54-drill size orifice gauge. Given the operation issues of the selfcleaning design at this high pressure, it is not appropriate to provide an estimate in reduction of
vapor because of the large variability of the data set. Photos of the propane releases are shown in
Figure 16. Table 7 summarizes the results.
25
Battelle
Table 7.
Liquid Propane Release Flow Rates - Flow Reduction.
Test
Temperature
54-Drill Flow Rate
72-Drill Flow Rate Æ Flow
Self-Cleaning Flow Rate Æ Flow
Reduction from 54-Ddrill Flow
0F
355g/min
148 g/min Æ 58%
79 g/min Æ 78 %
50 F
511 g/min
204 g/min Æ 60%
157 g/min Æ 69%
100 F
686 g/min
275 g/min Æ 60%
NA Æ NA
Test Series 3 – Susceptibility to Clogging Tests
Test Sequence
A suitable pressure containment piping system that included a pressurized water reservoir, (33
Lb propane lift truck cylinder), a compressed gas supply with an adjustable pressure regulator, a
flexible hose connector, with a shutoff valve, a 2-inch NPT PVC piping segment with a side
pressure tap, and water collection container was assembled and pressure tested.
The outlet from each gauge sample was directed into the water collection container and care was
taken during testing to minimize the loss of liquid being discharged from the sample at each test
pressure.
At the start of the test sequence, the pressurized water reservoir (PWR) was filled with
approximately 40 liters of clean water. The pressure regulator was connected to the vapor outlet
of the PWR. The container was refilled with liquid as necessary for these tests.
Each of the nine samples was installed individually at the end of the 2-inch NPT PVC piping
arrangement. With each sample initially in a closed position, gas pressure was applied to the
system using the compressed gas regulator with the shutoff valve to the pipe segment in an open
position until the 2-inch NPT PVC pipe assembly with sample is at the first test pressure (20
psig) in the static condition as measured at the pipe side tap.
By applying gas pressure to the vapor portion of the PWR, and by slowly opening the sample
thumbscrew two complete turns (full open position), water was allowed to flow through the
gauge sample. The pressure was adjusted to obtain a constant pressure of 20 psig at the pressure
gauge port in the side of the piping arrangement. The output from the sample was collected in a
suitable container for approximately two minutes. Time was kept by using a stopwatch. The
amount of liquid collected was determined by weighing the discharge container before and after
the time period. The amounts measured were recorded on the datasheet.
For each test sample, after the amount of water that was discharged into the container to be
weighed, the shutoff valve upstream of the 2-inch piping system arrangement was closed, and the
pressure was allowed to decay to 0 psig. The sample was removed and the next sample installed.
This sequence was repeated until all nine samples were tested.
Then the test sequence was repeated again, but with an inlet test pressure of 175 psig being used.
A test sequence at an intermediate pressure of 80 psig was not conducted because we were
26
Battelle
interested in susceptibility to clogging which would likely occur at only the maximum or
minimum test pressure.
After all nine samples were tested at 20 and 175 psig pressures, the water in the PWR was
replaced with a water/polystyrene latex microspheres solution.
Method for Determining Concentration Level for a Water/Polystyrene Latex
Microsphere Solution
Following a review of the Technical Report and Appendices of the Final Report on Water and
Solid Contaminant Control in LP Gas - Docket 11353 [Osborne 2006] and using Figure 18 of
that report, we identified an approximate worst case scenario. In it, particulate sizes that may be
found in propane can be represented by microspheres with the following sizes: 11, 85, and 222
microns. Further, using the ASTM D 1835 propane specification, the maximum amount of
residual matter on the evaporation of 100 ml of propane is 0.05 ml. Using these two data sets,
the known percentage of solids contents of the microspheres, assuming a packing density of
approximately 65 % and using the Derivation of Count per Milliliter for % Solids Technical
Note from Duke Scientific, we determined the following amounts of micropsheres to be placed
in one gallon of water.
11-micron size particles – 0.066 ml
Since the controlling amount is the 222-micron size particles and having 45 ml of that size of
particle available, we made 45/8.2 per gallon = 5.488 gallons (20.770 Liters) of solution. We
used the following amount of microspheres to create the solution for testing. All nine samples
were tested using this solution with the same equipment.
27
Battelle
Results for Task 2, Test 3
Table 8.
Results of Clogging Tests: Flow Rate Through FMLLG Using Water at
Specified Pressures.
Container Weight,
grams
Pressure,
psig
Sample
Tare
Final
Total
Water
Amount,
grams
20
1
3205
5205
2000
2
1000
20
2
3205
5225
2020
2
1010
20
3
3205
5270
2065
2
1033
20
4
3205
3790
585
2
293
20
5
3205
3704
499
2
250
20
6
3205
3732
527
2
264
20
7
3205
4078
873
2
437
20
8
3205
3574
369
2
185
20
9
3205
3971
766
2
383
175
1
1112
6131
5019
2
2510
175
2
1112
6000
4888
2
2444
175
3
1112
6150
5038
2
2519
175
4
1112
2454
1342
2
671
175
5
1112
2383
1271
2
636
175
6
1112
2406
1294
2
647
175
7
1112
3476
2364
2
1182
175
8
1112
2646
1534
2
767
175
9
1112
3438
2326
2
1163
28
Water Flow Rate,
grams/min
Time,
min
Water
Flow rate,
grams/min
Average
Std Dev
1014
16.65
269
21.93
335
132.77
2491
40.84
651
18.11
1037
234.31
Battelle
Table 9.
Results of Clogging Tests: Flow Rate Through FMLLG Using
Water/Microspheres at Specified Pressures.
Container Weight,
grams
Test No.
Pressure,
psig
Sample
Tare
Final
Amount of
Water/
Microsphere
Solution,
grams
Water/Microsphere Solution Flow
Rate, grams/min
1
20
1
1115.6
2923.2
1807.6
2
904
2
20
2
1123.8
2945.4
1821.6
2
911
3
20
3
1120
2996
1876
2
938
4
20
4
1121.5
1522
400.5
2
200
5
20
5
1118.1
1624
505.9
2
253
6
20
6
1120.7
1335
214.3
2
107
Retest
20
4
1114.4
1645.2
530.8
2
265
Retest
20
5
1116.6
1621.9
505.3
2
253
Retest
20
6
1118.3
1648.2
529.9
2
265
7
20
7
1118.6
1942.5
823.9
2
412
8
20
8
1118.7
1415.6
296.9
2
148
9
20
9
1116.4
1899.8
783.4
2
392
10
175
1
1112.2
6081.3
4969.1
2
2485
11
175
2
1117.9
6028.7
4910.8
2
2455
12
175
3
1117
6210.2
5093.2
2
2547
13
175
4
1114
2467.4
1353.4
2
677
14
175
5
1119.5
2385.5
1266
2
633
15
175
6
1119.8
2393
1273.2
2
637
16
175
7
1118.2
3304.8
2186.6
2
1093
17
175
8
1119.2
1857.1
737.9
2
369
18
175
9
1119.5
3366.3
2246.8
2
1123
Time,
min
Flow rate
Average
Std Dev
918
18.07
187
73.83
261
7.23
317
146.64
2496
46.58
649
24.26
862
427.16
Notes
Test No.1-18 were conducted on January 26, 2009; retest of samples 4-6 was conducted on January 28, 2009.
Temperature of solution = 73 F; Room Temperature = 75 F.
Water/microsphere solution contained: 0.066 ml of 11 micron size particles, 4.6 ml of 85 micron size particles, and 8.2 ml of
222 micron size particles for each gallon of water used.
Approximately 5.488 gallons (20.770 liters) of deionized water was used.
After Test nos. 9 and 12, the water/microsphere solution was transferred from the collection container to the pressurized
container.
For the retesting the water/microsphere solution was transferred from the collection container to the pressurized container.
29
Battelle
Table 10. Results of Clogging Tests: Comparison of Flow Rates Using Water and Flow
Rates Using Water/Microsphere Solution.
Water Flow Rate, grams/min
Water/Microsphere Solution Flow
Rate, grams/min
Pressure,
psig
Sample
Measured
Average
Std Dev
Measured
Average
Std Dev
20
1
1000
1014
16.6
904
918
18.1
20
2
1010
911
20
3
1033
938
20
4
293
187
73.8
20
5
250
253
20
6
264
107
20
4*
N/A
261
7.23
20
5*
N/A
253
20
6*
N/A
265
20
7
437
317
146.6
20
8
185
148
20
9
383
392
175
1
2510
2496
46.6
175
2
2444
2455
175
3
2519
2547
175
4
671
649
24.3
175
5
636
633
175
6
647
637
175
7
1182
862
427.2
175
8
767
369
175
9
1163
1123
269
N/A
335
2491
651
1037
21.9
N/A
132.8
40.8
18.1
234.3
200
265
412
2485
677
1093
*Retest.
From the water and water and microsphere solution test results it is clear that the 72-drill size
orifice and the self-cleaning design gauges do reduce liquid flow rates to atmosphere when
compared to the standard 54-drill size orifice.
Operational problems still persisted with the self-cleaning design but not to the same degree as
with the other tests.
30
Battelle
At no time did we observe clogging of either of the two small orifice designs at both test
pressures.
Figure 17. Clogging test – representative result.
31
Battelle
CONCLUSIONS
Tests were performed on samples of fixed maximum liquid level gauges, intended for use on
propane containers. Three types of samples were tested – gauges with standard 54-drill orifices,
gauges with smaller diameter 72-drill orifices, and self-cleaning units. Three series of tests were
performed on the samples: air flow tests with subsequent calculations of propane vapor flow
rates; liquid propane flow rates, including susceptibility of the orifice to freeze with liquid
propane saturated with water; and susceptibility of the orifices to clog using particulates in a
water solution.
The 72-drill samples demonstrated reduced gas flow rates by over 70 percent from the 54-drill
flow rates. The self-cleaning orifices also achieved significant flow rate reductions (just under 70
percent), however the samples exhibited problems with the seats being pushed out of the
housings at the highest test pressure of 175 psig. Likewise, the 72-drill samples demonstrated
approximately a 60 percent reduction of the liquid propane flow rate of the 54-drill. The selfcleaning units demonstrated a greater reduction, achieving approximately 60 percent reductions.
Again however, the seats were pushed out from the gauge bodies, generating wide variations in
the flow rates.
None of the samples demonstrated any indications of freezing in the orifices. The clogging tests
also demonstrated that none of the samples were susceptible to clogging, using polystyrene beads
in a water solution as surrogate for particulates in propane under the established test conditions.
32
Battelle
REFERENCES
LP–Gas 2007. “Fugitive on the loose”, LP-Gas Magazine, June 2007
(http://www.lpgasmagazine.com/lpgas/content/contentDetail.jsp?id=435011)
NFPA 2008. NFPA 58, Liquefied Petroleum Gas Code, 2008 Edition, National Fire Protection
Association, Quincy, MA, 2007.
NPGA 2007. “Strategic Plan Update, February 2007”, National Propane Gas Association
(www.npga.org)
Water and Solid Contaminant Control in LP Gas, Docket 11353, Battelle Memorial Institute for
Propane Education & Research Council, Washington, DC, 2006.
33
Battelle

Testing and Evaluation of New Low

Transcription

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