Hand Tool Project - A handpump worked on during. No practical due to COVID PDF

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A handpump worked on during. No practical due to COVID...

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HAND TOOL PROJECT MANUFACTURING ENGINEERING - 48621

UNIVERSITY OF TECHNOLOGY SYDNEY JANILA SANDA MARAKKALA - 13241916

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Contents 1.0

Introduction................................................................................................................................ 2

2.0

Research and Calculations ..................................................................................................... 2

2.1

Lift Pump................................................................................................................................ 2

2.2

Analysis and Calculations ................................................................................................... 2

3.0

Design ........................................................................................................................................ 3

3.1

Body ....................................................................................................................................... 3

3.2

Piston ..................................................................................................................................... 3

3.2.1

Piston Assembly ........................................................................................................... 4

3.3

Foot Valve ............................................................................................................................. 4

3.4

Junction.................................................................................................................................. 5

3.5

Cap ......................................................................................................................................... 5

3.6

Assembly ............................................................................................................................... 6

4.0

Materials .................................................................................................................................... 7

4.1

PVC 40 DN ............................................................................................................................ 7

4.2

Aluminium .............................................................................................................................. 7

4.3

Nylon Reinforced Rubber .................................................................................................... 7

5.0

Manufacturing Process ............................................................................................................ 8

5.1

Process and Equipment ...................................................................................................... 8

5.1.1

Figure 12: Manufacturing Process Flow Chart ........................................................ 8

5.1.2

Industrial Cold Saw ...................................................................................................... 9

5.1.3

Lathe............................................................................................................................... 9

5.1.4

Drill Press ...................................................................................................................... 9

5.1.5

Hand Drill ....................................................................................................................... 9

5.1.6

Tap and Die................................................................................................................... 9

5.1.7

Round File ..................................................................................................................... 9

5.1.8

Sandpaper ................................................................................................................... 10

5.1.9

Snipping Tool .............................................................................................................. 10

5.2

Manufacturing Costs .......................................................................................................... 10

5.2.1

Material Costs ............................................................................................................. 10

5.2.2

Labour Costs and Overhead Costs ......................................................................... 10

5.2.3

Machine and Equipment Costs ................................................................................ 10

6.0

Quality Assurance and Inspection ....................................................................................... 10

7.0

References .............................................................................................................................. 11

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1.0 Introduction The purpose of this project is to design a pump that is economically viable for remote communities in developing countries. It will have to be a hand pump that is able to do 2L per minute, whilst requiring minimal force so it’s easy to use. There are Manufacturing constraints restraints that would have to be followed. A PVC drainpipe with nominal diameter of 40mm must be used and it also must have a Maximum stroke of 100mm. Furthermore a 25.00 mm long M6 thread is required at the end shaft for testing. The design would have to be durable for long term use however with cost efficient manufacturing techniques and materials.

2.0 Research and Calculations 2.1 Lift Pump The type of Pump that would be used in this would be a Lift Pump, as it’s a simple design and the volume it’s able to pump is dependants on the diameter of the pipe and the length of the stroke. As shown in figure 1 the Lift Pump works due to flexible membranes acting as valves only allowing the water to flow up whether the pistons moving up or down. There are two valves in most lift pumps, ones on the foot of the pump and the other on the piston. These valves could be made from a cheap and flexible material like rubber. The body and the Junction could be made of a sturdy material like steel or plastic.

Figure 1: Lift Pump Concept (Old water pumps, 2020)

2.2 Analysis and Calculations The constraints that effect the design the most is the 40mm ND of the pipe and the 100mm stroke of the piston. The volume per stroke will be restricted these dimensions, this design would have to use this maximum of these constraints to get the best results. According to the project Outline the pump should be able to pump 2L in a minute. According to the Australian standards AS/NZS 1260-2009 (Standards Australia 2009) a 40 ND Pipe would have a maximum OD of 43.1mm and wall thickness of 2mm. Therefore, the ID would be around 39.1mm, this would help us to find the Volume per Stroke according to these constraints. Finding Volume Per Stroke: 𝑉 = 𝜋𝑟 2 ℎ 𝑉 = 𝜋 × 0.03912 × 0.1 𝑉 = 0.00048 𝑚3 𝑉 = 0.480 𝐿 Due to these restrictions, the hand pump would be able to pump 2L minimally in around 5 strokes. There would be other factors that would affect the number of strokes to reach this target. Such as the length of the main body, longer means more strokes initially before water starts pouring out of the faucet. Another factor would be how easily the water would travel through the piston valves and foot valves which would influence the force need to pump the water.

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3.0 Design The design has been developed after considering these design constraints as well as the function and material costs.

3.1 Body The water would be pumped through the length of this pipe to reach the faucet. This part would be a PVC drainpipe with ND of 40mm. The surface finish on the inside diameter would have to be smooth to allow the easy movement of the piston. The rest of the components would be influenced by the inside diameter of this section, so accurate measurement must be taken. Maximum length allowed for this section according to the project outline was 500mm however it was made far shorter to make it sturdier. This will also decrease the initial strokes needed for the water to flow.

Figure 2: Hand Pump - Body

3.2 Piston The piston both lifts the water through the body, to the top as well as sucks the water in from a water reservoir into the hand pump. The rubber valve attached to the top of the piston allows the water to travel through a hole on downward stroke. This rubber valve then seals the water above the piston when the upwards stroke begins. This piston would be made from a dense material so it can travel through the water against the bouncy. The holes would cover a large area to allow the water to come through the piston with ease. Machining and the surface finish of this component must be extremely accurate. If the diameter is slightly too large it would have a hard travelling through the body. Too small would allow the water to leak through to the bottom from around the edges of the piton. The 6mm hole would thread so it could be screwed into the metal rod during the assembly of the piston.

Figure 3: Hand Pump - Piston Head

Figure 4: Hand Pump – Rubber

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3.2.1 Piston Assembly The piston and the rubber valve would be assembled on a 375 mm metal rod. Both ends would be threaded, the top would have a threaded length of 25 mm to meet the design requirements. The thread on the bottom end would attach the Piston head and the rubber valve to each other as well as to the metal rod. This would be done with the help two hex nuts tightened at both ends. There would be rubber washers in between to make it as watertight as possible. The Piston head might need a rubber O ring to prevent leakage as well as to protect the body from wear and tear due to the friction from the piston.

Figure 5: Hand Pump – Piston Assembly

3.3 Foot Valve The foot valve acts as a one-way valve for water to enter the Hand Pump, letting the water in during the upward stroke of the piston and sealing it during the downward stroke. This is done with the help of the rubber strip connected to the top of the foot with a M6 bolt. The foot would be made from PVC with Dimensions per standard AS/NZS 1260-2009. The measurements are based on the dimensions given in (DWV Pipes and Fittings - Pipe King - Australia's leading independent PVC Pipe and Fittings manufacturer, 2020). The Inside diameter would be the Outside diameter of the Body. Dimension for the holes shown in figure 6 would be the same dimension as the piston. The M6 Hex bolt and the Figure 6: Hand Pump – Foot Valve Assembly Hex Nut would secure the Rubber valve on to the foot so it could act like a one-way valve, letting the water while preventing it from leaking out. There would be rubber washers just like the piston head to make it as watertight as possible. When attaching the foot Valve, it must be considered whether it’s watertight to prevent leaking.

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3.4 Junction The Junction would be a PVC pipe of Schedule 40 ND according to AS/NZS 1260-2009, the dimensions shown would be according to (DWV Pipes and Fittings - Pipe King - Australia's leading independent PVC Pipe and Fittings manufacturer, 2020). This component would be acting as a faucet for the pumped water to pour out. It would be attached to the body in a way that it would be watertight, so the only way the water would escape is from the mouth.

Figure 7: Hand Pump – Junction

3.5 Cap The Cap would seal the top of the pump to prevent exposure to outside debris when not in use. It also has the task of ensuring that the piston maintain a straight motion as the water is being pumped through the 6mm hole drilled on to it. This would be attached to the top of the junction through a 40ND pipe that would act like a coupling.

Figure 8: Hand Pump – Top

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3.6 Assembly

Figure 9: Hand Pump Assembly w/o Piston

Figure 10: Hand Pump Assembly

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4.0 Materials 4.1 PVC 40 DN PVC is a sturdy material with light weight, being easy to machine and resistant to weather and corrosion. It’s a perfect cheap substitute for metal as it’s not prone to rust, especially important for a water pump in rural areas. This material needs minimal surface finish as it’s already a smooth material allowing less friction and easy movement of the piston. This will be the main material used in the building process of the Hand Pump, specifically Shed 40 ND drain in AS/NZS 1260-2009 (Standards Australia 2009) for components listed below. -

Top Coupling Junction Body Foot

4.2 Aluminium Aluminium is strong ,light weight, easy to machine and more resistant to corrosion than other metals like steel. It’s more expensive than PVC however stronger and more durable, good for the smaller parts in the hand pump. Other substitutes like steel would rust in this sort of environment and would has low life expectancy especially when submerged in water. This deterioration of wood or Steel in the hand pump would cause some Health and Safety issues for its user. Although Aluminium corrodes, the aluminium oxide is a hard material which protects it from rust. Furthermore, Aluminium oxide is only harmful in high concentrations. The components which would be using this material is listed below. Aluminium is chosen for this material as it’s a denser substitute to plastic therefore capable of going against the bouncy forces of the water. -

Rod: 6mm diameter Aluminium Rod M6 Hex Bolt M6 Hex Nut Piston Head: 40mm diameter Aluminium rod

4.3 Nylon Reinforced Rubber

Figure 11: (Natural Insertion Rubber Heavy Duty Nylon Reinforced -Superior - Reglin, 2020)

This material was chosen over typical rubber due to its durability and higher life expectancy, good for the application of the rubber valve. It’s perfect for the application of the flexible membrane on the piston and foot valves, allowing the water to move up as well as preventing it from going down. This material would be easy to cut various shapes and sizes.

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5.0 Manufacturing Process 5.1 Process and Equipment 5.1.1 Figure 12: Manufacturing Process Flow Chart

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5.1.2 Industrial Cold Saw A cold saw would be used to cut the 40 ND PVC pipe as well as the rod. Unlike the hacksaw the Cold Saw is very accurate and can cut at low tolerances. It also takes less effort and energy to cut with the cold saw in comparison to the hack saw. Using this machine would result in better finish and require minimum grinding or filing to get it to the correct dimensions. The use will be relatively straight forward, mark the PVC pipe or the Aluminium Rods to their correct lead and then cut across the marked line with the Cold Saw. There are of course prior safety procedures that must take place before using this machinery.

5.1.3 Lathe A lathe is a versatile machinery that can cut, drill holes and surface finish cylindrical objects. The Lathe would be used to grind down the piston head slightly to get it to the correct diameter of 39mm, therefore making it able to fit through the body. It would also be used to cut down this Aluminium bar to length of 5mm thickness as this thickness would be too small to be done on the Cold Saw, this would be done by the cutting tool of the lathe.

5.1.4 Drill Press The Drill press would only used on the on the 40mm Aluminium Bar that is cut to 5mm due to its high power. However, it has a slow set up time compared to the hand drill, so it won’t be used to drill holes on the PVC components due to them having easier machining capabilities. It can drill with high accuracy as well as give a more stable platform to drill. Before drilling mark the points using a hammer and punch, then drill smaller pilot holes before drilling the 6mm and 14mm Diameter holes. The 14mm D holes is for the Piston valves holes which have 3 holes overlapping each other.

5.1.5 Hand Drill The Hand Drill is straight forward and easy to use, it would be used to drill and machine the PVC parts like the Top and the Foot Valves. This is because PVC is easy to machine as well as the Hand drill is easier to setup than the Drill press, saving time and effort. Drilling the 6mm holes on both ends would be a straightforward task, just need to mark the centre. Drilling the holes on the foot valves would be the same process used drilling the Piston valve holes.

5.1.6 Tap and Die The Tap is used to tapper threads in inside diameters with high accuracy, it’s a hard yet quite fragile when too much tensile stress is applied. Due to its hardness it can cut through ductile material like Aluminium easily. The M6 Tap would be used on the 6mm hole in the Piston head so the threaded aluminium rod could be screwed into it to make it as watertight as possible. A Die is used to tapper threads outside diameters and are highly accurate. An M6 die would tapper threads on the 375mm Aluminium rod on both sides. On the top it will be done to a length of 25 mm due to the design constraints given. The bottom would be done so that the rubber valve, 2 Hex Nuts and piston head would fit on the bottom.

5.1.7 Round File The Round file would be used to widen the drilled holes of the 5mm thick Piston head, in what to be the Piston Valve holes. It would be first done with a rougher and then moved down to the sandpaper as it gets closer to the desired dimensions. The round file would have to be quite small to fit through the 14mm D holes.

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5.1.8 Sandpaper Like the round file this would widen the drilled holes of the foot in what would be the Foot valves. The process would start with a rougher sandpaper to smoother finish as it gets closer to the desired dimensions. This could also be used to deburr the holes of the 40 ND pipe.

5.1.9 Snipping Tool The Snipping tool would be used to cut the 1.5mm round rubber valve as the material would be easy to cut as well as the snipping tool being an easy too control. A circular shape would be marked on the sheet of rubber before cutting. The hole in the centre would possibly be drilled or cut with the snipping tool.

5.2 Manufacturing Costs 5.2.1 Material Costs Material PVC Pipe PVC Junction PVC Cap Rubber Sheet

Cost per Unit $8.62 per 1m (Bunnings) $5.94 (Bunnings) $1.45 (Bunnings) $12.72 per 50mm x 5m (Home and

Cost $2.19 $5.94 $2.90 $0.08 (per 40mm x 40mm)

Materials, 2020)

6mm Aluminium Rod 40mm Aluminium Rod

$2.40 per 1m (Bunnings) $145 per 2,250 mm (Aluminium Rod Solid

$0.9 $3.22 (Est 50mm wasted)

Round 40mm Dia. 2250mm long. | eBay, 2020)

M6 Hex Bolt M6 Hex Nut Total

Approx $1 Approx $1

$3 $1 $19.23

5.2.2 Labour Costs and Overhead Costs Labour Costs would be dependant from country to Country as well as the time it takes to manufacture this product. As this does not need any highly skilled workers it could be done cheaply. Furthermore, Overhead costs would be hard to calculate currently.

5.2.3 Machine and Equipment Costs Equipment Costs Industrial Cold Saw $ 7,645.00 Lathe $1,206 Drill Press $ 2,189.00 Hand Drill $39.99 Tap and Die $149.99 Round File $16 Sandpaper $10 Snipping Tool $20 $11,275.98 Total The Heavy Machinery would be a long-term investment therefore would help with other projects as well, this would also include the hand tools such a...