Hydraulic ram and Solar Powered water pumping training manual

8/9/2019 Hydraulic ram and Solar Powered water pumping training manual

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Ram Pump

AndSolar Pump

Training

Fredrik Bjarnegard, Allen Chou, Sukon Tae Phunpunyakorakul, Yotin Pupaolan, Salinee Tavaranan

A collaboration of BGET TOPS ZOA KNCE TBCAF GREEN EMPOWERMENT PALANG THAI

BG E

T

BORDER GREEN ENERGY TEAM

BG E

TG E

T

BORDER GREEN ENERGY TEAM

Contact Us atBorder Green Energy Team

TOPS34/53 Mae Sod Mae Tao Rd

Mae Sod, TAK 63110055-542-068

Or

Border Green Energy Teamc/o TOPS

PO Box 66Mae Sod, TAK 63110

This manual is available at www.bget.org


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List of contents

Introduction............................................................................................................................................. 3 Water the primary source of life........................................................................................................ 3Different ways of pumping water ......................................................................................................... 3

Water Resources ..................................................................................................................................... 5

Surface water vs Groundwater.............................................................................................................. 5Water Demand ...................................................................................................................................... 5Water Storage ....................................................................................................................................... 6Water Distribution ................................................................................................................................ 6

Solar pumping.................................................. ....................................................................................... 8 The technology ..................................................................................................................................... 8Performance........................................................................................................................................ 10Designing a solar pumping system..................................................................................................... 11Calculation example ........................................................................................................................... 11

Hydraulic ram pump............................................................................................................................ 13 Introduction......................................................................................................................................... 13

How a hydram works.......................................................................................................................... 13Performance........................................................................................................................................ 15Designing a hydraulic ram pump system............................................................................................ 16Calculation example ........................................................................................................................... 17Installation requirements .................................................................................................................... 18

References..................................... ......................................................................................................... 20 Appendix............................................................................................................................................. ... 21

Appendix A Formulae for Energy and Power............................................................................. 22Appendix B Specification for Diesel Pump ................................................................................ 23Appendix C Specification for Solar Panels................................................................................. 24Appendix D Specification for Yeser 12 V DC water pump........................................................ 25

Appendix E Hydraulic Ram Pump Tuning................................................................................. 31Appendix F 1 Ram Pump Test Results ..................................................................................... 33Appendix G Steps in Installing Hydraulic Ram Pump System................................................... 40Appendix H Problems and Solutions during Ram Pump Installation......................................... 41

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Similarly, demand for livestock watering is estimated from the number of animals using the systemmultiplied by the per capita water consumption. Typical daily water consumption for farm animals isshown in Table 3.

Table 3 Typical Daily Water Consumption for Farm Animals

Type of Animal Daily Water Consumption(liters/animal)

Dairy cows 80Beef brood cows 50Horses and mules 50Calves 30Pigs 20Sheep and goats 10Chickens 0.1

Unlike demands for domestic and livestock water supplies, water demand for crop irrigation isseasonal. Because some crops require a maximum water supply for a relatively short growing season,all irrigation systems need to be designed for peak water demands. Estimating the water demand for an

irrigation application is complex and is beyond the scope of this training. However, local practice andexperience are probably the best guides to estimating water requirements for a specific application.Table 4 shows the estimated daily water requirements for various types of crop irrigation.

Table 4 Estimated Maximum Daily Water Demand for Various Types of Crop Irrigation

Crops Daily Water Requirement(m3/ha)

Rice 100Rural village farms 60Cereals 45Sugar cane 65Cotton 55

Water StorageStorage is necessary for good water management. The available power resource must be consideredwhen determining storage size. The size of water tanks for conventional systems depends only on the

peak and average daily water demand. PV systems, on the other hand, depend on daily weather conditions. Cloudy days with poor solar radiation create problems for meeting the daily water demand,so water tanks should be larger for such systems. Generally, 3 days of storage is recommended for renewable energy water pumping systems. Water tanks can be smaller if alternative water sources,such as hand pumps and rainwater, are available. In rural areas rainwater can be collected to water livestock and wash clothes, depending on the amount of annual rainfall distribution in the area. Surface

water that flows year-round (such as a river) can also be used for such tasks, reducing the need for large capacity water tanks.

Water DistributionTo distribute water fairly to the rural community, pumping it first to the tank and then distributing itfrom the tank by using gravity is recommended. This way, enough pressure can be built up at the water tank to distribute water by gravity. In addition, water will continuously flow in the tank, which helps toreduce the growth of bacteria. Finally, this helps maintain any leakage with little water loss and fewinterruptions to other distribution areas. However, distribution pipes must be sized carefully because

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smaller pipes create more friction than bigger pipes. Because oversized distribution pipes will raise theinvestment costs of the system, there are tradeoffs. The rural distribution network is relatively small, soleakage in these systems is less of a concern than in city water supplies. The water pressure in thedistribution pipe is generally low in these systems and the chances of the pipe bursting are veryunlikely.

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Solar pumpingPV technology converts the suns energy into electricity (DC) when the PV module (array) is exposedto sunlight. The PV module can also be used for AC applications using an inverter. PV is especiallysuitable for water pumping because energy need not be stored for night pumping. Instead, water can bestored to supply water at night.

The technology Solar pump systems are broadly configured into 5 types as described below:

Submerged multistage centrifugal motor pumpset (Figure 1)

This type is probably the most common type of solar pumpused for village water supply. The advantages of thisconfiguration are that it is easy to install, often with lay-flatflexible pipework and the motor pumpset is submergedaway from potential damage. Either ac or dc motors can be

incorporated into the pumpset although an inverter would be needed for ac systems. If a brushed dc motor is usedthen the equipment will need to be pulled up from the well(approximately every 2 years) to replace brushes. If

brushless dc motors are incorporated then electroniccommutation will be required. The most commonlyemployed system consists of an ac pump and inverter witha photovoltaic array of less than 1500Wp.

Figure 1 Submerged multistage centrifugal motor pumpset

Submerged pump with surface mounted motor ( Figure 2) This configuration was widely installed with turbine

pumps in the Sahelian West Africa during the 1970s. Itgives easy access to the motor for brush changing andother maintenance. The low efficiency from power losses in the shaft bearings and the high cost of installation has been disadvantages. In general thisconfiguration is largely being replaced by thesubmersible motor and pumpset.

Figure 2 Submerged pump with surface mounted motor

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Reciprocating positive displacement pump ( Figure 3)

The reciprocating positive displacement pump (oftenknown as the jack or nodding donkey) is very suitable for high head, low flow applications. The output is

proportional to the speed of the pump. At high heads the

frictional forces are low compared to the hydrostatic forcesoften making positive displacement pumps more efficientthan centrifugal pumps for this situation. Reciprocating

positive displacement pumps create a cyclic load on themotor which, for efficient operation, needs to be balanced.Hence, the above ground components of the solar pump areoften heavy and robust, and power controllers for impedance matching often used.

Figure 3 Reciprocating positive displacement pump

Floating motor pump sets (Figure 4)

The versatility of the floating unit set, makes it ideal for irrigation pumping for canals and open wells. The pumpset iseasily portable and there is a negligible chance of the pumprunning dry. Most of these types use a single stagesubmersed centrifugal pump. The most common type utilisesa brushless (electronically commutated) dc motor. Often thesolar array support incorporates a handle or 'wheel barrow'type trolley to enable transportation.

Figure 4 Floating motor pump sets

Surface suction pumpsets (Figure 5)

This type of pumpset is not recommended except where anoperator will always be in attendance. Although the use of

primary chambers and non-return valves can prevent lossof prime, in practice self-start and priming problems areexperienced. It is impractical to have suction heads of more than 8 meters.

Figure 5 Surface suction pumpsets

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PerformanceThe performance of some commercially available products is shown in Figure 6. It can be seen thatsolar pumps are available to pump from anywhere in the range of up to 200m head and with outputs of up to 250m 3/day. The product of head and output is defined as m 4. DC pumps normally have m 4 value

below 1500-2000. Many systems pump water using solar energy with m 4 above 2000, but here theyuse AC pumps and inverters and are getting into much larger systems. The m 4 diagram of the 50W DC

pump that we will use for demonstration purposes during this training can be found in Appendix D.

Figure 6 Performance of solar pumps

Solar pumping technology continues to improve. In the early 1980s the typical solar energy tohydraulic (pumped water) energy efficiency was around 2% with the photovoltaic array being 6-8%efficient and the motor pumpset typically 25% efficient. Today, an efficient solar pump has an averagedaily solar energy to hydraulic efficiency of more than 4%. Photovoltaic modules of the

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Hydraulic ram pump

IntroductionThe hydraulic ram pump, or hydram, concept was first developed by the Mongolfier brothers in Francein 1796 (they are better remembered for their pioneering work with hot-air balloons).

Essentially, a hydram is an automatic pumping device which utilizes a small fall of water to lift afraction of the supply flow to a much greater height; i.e. it uses a larger flow of water falling through asmall head to lift a small flow of water through a higher head. The main virtue of the hydram is that itsonly moving parts are two valves, and it is therefore mechanically very simple. This gives it very highreliability, minimal maintenance requirements and a long operation life.

How a hydram worksIts mode of operation depends on the use of the phenomenon called water hammer and the overallefficiency can be quite good under favorable circumstances. More than 50% of the energy of thedriving flow can be transferred to the delivery flow.

Figures 7-10 illustrates the principle; initially (Figure 7) the impulse valve (or waste valve since it isthe non-pumped water exit) will be open under gravity (or in some designs it is held open by alight spring) and water will therefore flow downthe drive pipe (through a strainer) from the water source. As the flow accelerates, the hydraulic

pressure under the impulse valve and the static pressure in the body of the hydram will increaseuntil the resulting forces overcome the weight of the impulse valve and start to close it. As soonas the valve aperture decreases, the water

pressure in the hydram body builds up rapidlyand slams the impulse valve shut.

The moving column of water in the drive pipe isno longer able to exit via the impulse valve so its

velocity must suddenly decrease; this continues tocause a considerable rise of pressure which forcesopen the delivery valve to the air-chamber. Oncethe pressure exceeds the static delivery head,water will be forced up the delivery pipe (Figure8).

Figure 8

Figure 7

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PerformanceThe flow of water that a hydraulic ram pump can deliver depends on the head ( H ) and flow ( Q) of thewater from the drive pipe, as well as the delivery head ( h), i.e. the height difference between the ram

pump and the storage tank where the water should be pumped. The delivery flow ( q) can be calculatedusing the following formula:

hQ H f q =

where f is the efficiency factor, H is the supply head, Q is the supply flow, and h is the delivery head.A typical efficiency factor for commercial ram pumps is 60%, but up to 80% is possible. For homemade ram pumps this is usually lower.

HD

h

d

Catchment tank

q

l

L

Q

Drive pipe

Delivery pipe

Storage tank

Ram pump

Figure 11 Schematic of ram pump installation

The size and length of the drive pipe must be in proportion to the working head from which the ramoperates. Also, the drive pipe carries severe internalshock loads due to water hammer, and therefore normallyshould be constructed from good quality steel water pipe.

Normally the length (L) of the drive pipe should bearound three to seven times the supply head (H). Ideallythe drive pipe should have a length of at least 100 but notmore than 1,000 times its own diameter (D). The drive

pipe must generally be straight; any bends will not only

cause losses of efficiency, but will result in strongfluctuating sideways forces on the pipe, which can causeit to break loose.

Technical Parameters for Hydraulic Ram Pump System

,

where

L = length of drive pipeH = supply headD = diameter of drive pipe

000,1100) = D L

b73) = H L

a

Hydrams are mostly intended for water supply duties, in hilly or mountainous areas, requiring smallflow rates delivered to high heads. They are less commonly used for irrigation purposes, where thehigher flow rates required will usually demand the use of larger sizes of hydram having 6-inch or 4-inch drive pipes. Manufacturers usually describe the size of a hydram by the supply and delivery pipediameters (generally given in inches even in metric countries because of the common use of inch sizes

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for pipe diameters); e.g. a 6 x 3 hydram has a 6-inch diameter drive pipe and a 3-inch diameter delivery pipe. Table 5 indicates estimated performance for typical 4-inch x 2-inch and 6-inch x 3-inchcommercial hydrams.

Table 5 Typical ram pump performance data

Hydram size in inches 4 x 2 6 x 3Head ratio ( h/H ) 5 10 15 20 5 10 15 20Drive flow Q (litres/s) 9.0 9.7 10.0 9.0 20.2 17.2 17.1 19.3Delivery flow q (m3/day) 94 51 35 23 216 101 69 50Efficiency f 61% 61% 61% 59% 62% 68% 70% 60%

The ram pump that will be used for demonstration purposes during this training is manufactured by theAID foundation in the Philippines. It has a 1 drive pipe and a delivery pipe. The performance datafor this ram pump can be found in Appendix F.

Designing a hydraulic ram pump systemThe following are the steps in designing a hydraulic ram pump system:

1. Identify the necessary design factors:

1. What is the available supply head, H (the height difference between the water source and the pumpsite)?

2. What is the required delivery head, h (the difference in height between the pump site and the pointof storage or use)?

3. What is the available drive flow, Q (the quantity of flow from the water source)?4. What is the required delivery flow, q (the quantity of water for consumption)?5. What is the length of the drive pipe, L (the distance from the source to the pump site)?6. What is the length of the delivery pipe, l (the distance from the pump to the storage site)?

2. Determine if this is a do-able projectCalculate the required efficiency factor using the formula

Q H qh

f

=

to see if it is possible to use a ram pump to meet the supply demand.The angle of the drive pipe should not be too steep. Normally the length ( L) of the drive pipe should bearound three to seven times the supply head ( H ).

3. Determine the ram pump size

The table below shows the capacities for different ram pump sizes from a certain manufacturer, as well

as the recommended size of the drive pipe.Table 6 Capacities for different ram pump sizes 3

Hydram size 1 2 3 3.5 4 5X 6XDrive flow needed(liters/min)

7-16 12-25 27-55 45-96 68-137 136-270 180-410

Maximum lift (meters) 150 150 120 120 120 105 105Drive pipe size (inches) 1 1 2 2 3 4 5

3 US AID, 1982

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4. Determine the drive and delivery pipe size

The drive pipe diameter is usually chosen based on the size of the ram and the manufacturer'srecommendations as shown in Table 6. But there are also other factors to consider. The diameter of

both the drive pipe and the delivery pipe should not be smaller than their respective length divided by1,000. If the diameter is too small the capacity will be reduced due to friction losses. The diameter should also be large enough to handle the flow of water that should go through it. The table below can

be used for finding the right pipe size for the available flow.Table 7 Possible flows for different pipe sizes 4

Pipe diameter (inches) 1 1.5 2 3 4Flow (liters/min) 6-36 37-60 61-90 91-234 235-360

Calculation exampleA small community consists of 10 homes with a total of 60 people. There is a spring l0m lower thanthe village, which drains to a wash 15m below the spring. The spring produces 30,000 liters of water

per day. There is a location for a ram on the bank of the wash. This site is 5m higher than the wash and35m from the spring. A public standpost is planned for the village 200m from the ram site. The lift

required to the top of the storage tank is 23m.

1. Identify the necessary design factors:

1. The available supply head, H , is 10m.2. The required delivery head, h, is 23m to the top of the storage tank.3. The quantity of flow available, Q, equals 30,000 liters per day divided by 1,440 minutes per day

(30,000/1,440) = 20.8 liters per minute.4. The quantity of water required, q, assuming 40 liters per day per person as maximum use is 60

people x 40 liters per day = 2,400 liters per day.2,400/1,440 = 1.66 liters per minute (use 2 liters per minute)

5. The length of the drive pipe, L, is 35m.6. The length of the delivery pipe, l , is 200m.

2. Determine if this is a do-able project

Calculate the required efficiency factor using the formula

22.08.2010

223=

=

=

Q H qh

f

22% efficiency is VERY do-able for a hydraulic ram pump installation.

Calculate the ratio between the length of the drive pipe ( L) and the supply head ( H ).

5.31035

==

H L

The length of the drive pipe should be at least three times the supply head, so this condition is also met.

3. Determine the ram pump size

Table 6 can now be used to select a ram size. The volume of driving water or supply needed is 20.8liters per minute. From Table 6, a No. 2 Hydram requires from 12 to 25 liters per minute. A No. 2

4 US AID, 1982

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Hydram can lift water to a maximum height of 150m according to Table 6. This will be adequate sincethe delivery head to the top of the storage tank is 23m. Thus, a No. 2 Hydram would be selected.

4. Determine the drive and delivery pipe size

Table 6 shows that for a No. 2 Hydram, the minimum drive pipe diameter is 1 inch. The length of thedrive pipe is 35 meters, so the diameter should not be less that 35 mm. Thus a 1 (38 mm) pipewould be sufficient. Table 7 shows that a 1 pipe is sufficient for the drive flow (20.8 liters/min).

For the delivery flow (2 liters/min), Table 7 shows that a 1 pipe is sufficient

Installation requirementsFigure 12 illustrates a typical hydram installation, pumping water to a small storage tank on a plateau.It can be seen that the supply head is created in this case by creating a weir. In some cases a smallstream is diverted to provide the water supply.

Figure 12 Typical ram pump installation

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Where greater capacity is needed, it iscommon practice to install severalhydrams in parallel. This allows achoice of how many to operate at anyone time so it can cater for variablesupply flows or variable demand.

Figure 13 shows an installation with parallel ram pumps.

Figure 13

Multiple hydrams withcommon delivery pipe

The hydram body requires to be firmly bolted to a concrete foundation, as the beats of its action applya significant shock load. The hydram should be located so that the waste valve is always located aboveflood water level, as the device will cease to function if the waste valve becomes submerged. Thedelivery pipe can be made from any material capable of carrying the pressure of water leading to thedelivery tank. In all except very high head applications, plastic pipe can be considered; with highheads, the lower end of the delivery line might be better as steel pipe. The diameter of the delivery lineneeds to allow for avoiding excessive pipe friction in relation to the flow rates envisaged and thedistance the water is to be conveyed. It is recommended that a hand-valve or check-valve (non-returnvalve) should be fitted in the delivery line near the outlet from the hydram, so that the delivery linedoes not have to be drained if the hydram is stopped for adjustment or any other reason. This will alsominimize any back flow past the delivery valve in the air chamber and improve efficiency.

For steps in installing hydraulic ram pump systems, please refer to Appendix G.

For problems that may occur during installation of ram pump systems, please refer to Appendix H.

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ReferencesThe material for this training manual has been taken from the following sources:

N. Argaw, R. Foster and A. Ellis, New Mexico State University, Las Cruces, New Mexico, USA,Renewable Energy for Water Pumping Applications in Rural Villages, NREL/SR-500-30361

Available electronically at http://www.osti.gov/bridge

Technical Information ServicePractical Action (formerly: Intermediate Technology Development Group)The Schumacher Centre for Technology and DevelopmentBourton-on-DunsmoreRugby, CV23 9QZUnited KingdomTel: (+44) 1926 634400Fax: (+44) 1926 634401e-mail: [email protected]

web: http://www.itdg.org http://www.itdg.org/docs/technical_information_service/solar_pv_waterpumps.pdf http://www.itdg.org/docs/technical_information_service/hydraulic_ram_pumps.pdf

AID FoundationAlternative Indigenous Development Foundation Inc.PO Box 297Lot 30, Blk. 12, Puentebella Subd.,Brgy. Taculing, Bacolod City,PhilippinesTel: (+63) 34 446 3629

Fax: (+63) 34 446 2336e-mail: [email protected]: www.aidfi.org

Other websites

http://www.newint.org/issue207/facts.htm

http://www.thefarm.org/charities/i4at/lib2/hydrpump.htm

http://www.dekpower-fj.com/diesel-water.htm

http://www.solartron.co.th/Newer/product.aspx

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http://www.osti.gov/bridgehttp://www.itdg.org/http://www.itdg.org/docs/technical_information_service/solar_pv_waterpumps.pdfhttp://www.itdg.org/docs/technical_information_service/hydraulic_ram_pumps.pdfhttp://www.aidfi.org/http://www.newint.org/issue207/facts.htmhttp://www.thefarm.org/charities/i4at/lib2/hydrpump.htmhttp://www.dekpower-fj.com/diesel-water.htmhttp://www.solartron.co.th/Newer/product.aspxhttp://www.solartron.co.th/Newer/product.aspxhttp://www.dekpower-fj.com/diesel-water.htmhttp://www.thefarm.org/charities/i4at/lib2/hydrpump.htmhttp://www.newint.org/issue207/facts.htmhttp://www.aidfi.org/http://www.itdg.org/docs/technical_information_service/hydraulic_ram_pumps.pdfhttp://www.itdg.org/docs/technical_information_service/solar_pv_waterpumps.pdfhttp://www.itdg.org/http://www.osti.gov/bridge


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Appendix

Appendix A Formulae for Energy and Power (1 page)

Appendix B Specification for Diesel Pump (1 page)

Appendix C Specification for Solar Panels (1 page)

Appendix D Specification for Yeser 12 V DC water pump (6 pages)

Appendix E Hydraulic Ram Pump Tuning (2 pages)

Appendix F 1 Ram Pump Test Results (7 pages)

Appendix G Steps in Installing Hydraulic Ram Pump System (1 page)

Appendix H Problems and Solutions during Ram Pump Installation (2 pages)

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Appendix A Formulae for Energy and Power

Energy can be in many different forms. It can never be destroyed, only transformed from one form of energy to another.

Potential energy, e.g. water stored in a reservoir h g mW =

where W is the energy in Joule (J), m is the mass of the water in kilograms (kg), g is the constant of gravity (~10 m/s 2), and h is the head in meters (m).

Electrical energy, e.g. stored in a batteryQU W =

where W is the energy in Joule (J), U is the voltage in Volts (V), and Q is the electric charge inCoulomb (C).

Power is the amount of energy per time and is expressed in Watts (W).

t W P =

where P is the power in Watts (W), W is the energy in Joule (J), and t is the time in seconds (s).

Water power, e.g. water flowing in a waterfallh g q P =

where P is the power in Watts (W), is the water density in kg/m 3, q is the flow in m 3/s, g is theconstant of gravity (~10 m/s 2), and h is the head in meters (m).

Electrical power, e.g. produced in a solar panel I U P =

where P is the electrical power in Watts (W), U is the voltage in Volts (V), and I is the current inAmperes (A).

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Appendix B Specification for Diesel Pump

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Appendix E Hydraulic Ram Pump Tuning

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Appendix F 1 Ram Pump Test Results

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Appendix G Steps in Installing Hydraulic Ram Pump System

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Appendix H Problems and Solutions during Ram Pump Installation

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Hydraulic ram and Solar Powered water pumping training manual

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