Assembly station PDF

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lab report on assembly station...

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1.Abstract The objective of this experiment is to develop practical skills by the re-assembly and disassembly of piping system and also to further understand the technical documents commonly used in industry. It also helped in the understanding of different valve types such as the switching fitting and adjustment fitting. Section A was disassembled whereas Section was re-assembled. There was no leakage observed in the piping system during the leak test. 2.Introduction Pipes are hollow cylinders used to convey fluids from one location to another whereas pipe fittings are used to connect lengths of pipes and adapt to different size or shapes. Valves are used to regulate and control the flow of a fluid. A piping system consists of a network of pipes, fittings and valves intended to perform a specific job (Amin, 2019). Pipes are used extensively in chemical industries such as oil and gas, pharmaceutical, food and many more. Applications of pipes range from piping systems in tank construction to pipelines for transporting contaminated wastewater and exhaust gas. (Anon, 2019) The materials used for pipe construction includes stainless steel, copper, polyethylene, polyvinyl chloride (PVC) and many more. Different materials are used based on their application. For example, copper pipe is useful for hot water supply systems as it can withstand high temperature (Anon, 2019) whereas PVC pipes are used for irrigation piping and building supply piping (Eavas, 2019). The objective of this experiment was to familiarize with technical terms and designation of piping elements through assembling and dissembling a section of the piping system. 3.Theory All the components in the assembly station rig shown in Table 1. Table 1: A list of all components in the assembly and its description Components Ball Valve

Shut-off valve Gate valve

Non-return valve

Dummy disc for flange connection Spectacle Blind for flange connection Pressure vessel with pressure gauge and steel flange Inspection glass

Description This switching fitting has a spherical gate with a cylindrical flow aperture that allows a rapid opening or closing. It is used when fluid needs to be interrupted quickly. It is a type of adjustment fitting that is used to shutoff and restrict the flow of media without leaks. It can be installed horizontally or vertically. A switching fitting that completely shuts off a pipe or open its full crosssection. In the open position, it provides the lowest possible flow resistance to the flowing medium. This is used where a reverse flow is not allowed. By installing it in the direction of flow in pipes, a spring will press onto the sealing disc when there is a pressure drop or a high back-pressure. It is used if a pipe is to be closed for a long duration. It consists if a metal disc with 2 seals, which is placed in between the flange connection. This is known as the combination of dummy and perforated disc. With this component, the flow aperture of the pipe can be reduced. A pressure vessel is a container designed to hold fluid at a pressure different from the ambient pressure. The pressure gauge indicates the pressure of the fluid inside the vessel. This is a flow indicator for liquids which also allows any fault in piping system to be detected.

Dirt trap Condensate drain T-piece Cutting ring fitting

Threaded flange with threaded fitting Flange with adapter Rapid action coupling Screw-in fitting Pipes L Pipes S185 Bend 90° with extension and steel flange

Dirt traps are fitted at the inlet of the pipe to retain any impurities. Impurities have to be removed to prevent clogging of the pipes. A control fitting that drain the condensate that forms in steam pipes. This prevents the liquid from gas flow damaging the pipe and other control fittings. It acts a pipe connection with 3 connection sites. A type of connection with cutting edge which cuts into the pipe when the nuts are tightened. It is usually used for pipes with small diameters which does not require the gland to be welded. It provides protection against leaks and ensures pipes are braced against vibrations. A pipe connection which has a detachable flange connection.

The adapter in the flange supports the pipe A component used to provide a fast way to repeatedly connect and disconnect fluid lines. This connection component is used to connect 2 components. It exists in many different lengths and DNs to transport fluid. This type of pipe has a smaller diameter and thinner walls compared to others. It allows the change in direction of a piping system.

4.Method

1

3

4

2

Figure 1: Pipe with 4 labelled bolts and nuts

Figure 2: A bolt and nut with 2 washers in between it Before the experiment was started, all the remaining water in the piping system were drained by opening the ball valve. The drained water was collected in a plastic box placed under the piping system to avoid spillage. The piping system was separated into 2 sections as shown in Figure 8 (Appendix A). Section 1 was disassembled from bottom to top which was from Item 34, followed by Item 4 and Item 35 (Figure 3). By using a pair of spanners, the bolts were loosened till it can be removed by hand. The nut was screwed onto the bolt after both washers were placed onto the bolt as shown in Figure 2 to avoid losing any parts. After the first bolt was loosen, the second bolt loosen was the one diagonally opposite and then followed by all others. For example, from Figure 1, there were 4 labelled bolts: bolt 1, bolt 2, bolt 3 and bolt 4, bolt 1 and bolt 3 were loosened, then bolt 2 and bolt 2 were loosened. The bolts were removed when all bolts were loosened. Section 2 was re-assembled from the top to bottom which was the following order: Item 31, Item 4, Item 6 then Item 4 and lastly Item 32. Item 16 was not included since it was already connected to the system. Each item was connected to the frame loosely until all items were in the correct positions. All the bolts were tightened with a pair of spanners after ensuring all the gasket in between each flange connection was in the center. A ratchet with a torque meter of 28 N/m was used to tighten all the bolts. When the re-assembly was completed, a leak test was conducted with an operating pressure of 3.5 bar. To check if all the connections were tight, the pipe system was filled up with water. The ball valve (Item 2) was closed to avoid water from draining out of the system. 5.Results There was no leak observed in the leak test which showed that the piping system was tight. From the pressure gauge, the pressure was observed to remain constant after an increase. 6.Discussion Part 1: The disassembly of Section 1 of the piping system was from the bottom to top. This is because some water might remain in the system even after the system was drained. Thus, loosening the bottom first meant the water could drain out at the bottom where it was not direct towards users’ face. The re-assembly of Section 2 was from the top to bottom instead. This is because if the last pipe does not fit then it is easier to readjust a pipe that is nearer to the ground than a pipe higher off the ground for safety reasons such as reducing the risk of falling down from a higher ground or dropping a heavy pipe from a higher ground too. Since the pressure remained constant after an increase, it proved that there was no leak in the piping system (Anon, 2017). To improve result, the leak test should be maintained for a minimum of 10

minutes (Smith, 2007). Thus, the leak test should be run for an hour to check if the pressure in the

system maintained constant to ensure no visible leakage throughout the test. A hydro test should also be carried out with a pressure 1.5 times of the operating pressure for a minimum of 1 hour (Curry, 2003). There was a mistake in the technical drawing where the non-return valve (Item 6) was placed in a position that had other components blocking it. Thus, the nuts were not able to fit in. The non-return valve was readjusted by turning 180 degree which meant the body was facing inwards of the piping system. The technical drawing should be updated with the correct position of each component. A table of bill of quantity should be included as well in the assembly drawing. It was observed that the water removed from the pipe system was brown. This was due to the corrosion of pipe. Therefore, it is important to have draining points to avoid the corrosion of pipe by draining out remaining water.

Figure 3: Piping elements that make up 5 sections that are suitable for partial assembly Table 2: Options for assembly sequence Assembly – sequence

Assembly – Option 1 Section

Assembly- Option 2 Section

1 2 3 4 5

A

A

C

B

B

C

D

E

E

D

Figure 2: A structure diagram showing assembly option 2 WP 2: Representation using graphic methods

Figure 3: A two-dimensional schematic diagram of Section B (symbols shown in WP4)

5. 47. 47.

3.

3.

51. Flange connection

15.

26.

Figure 4: Pipe drawing of Section B with labelled item numbers to the components Table 3: List of associated parts containing all components found in Section B. For the names of component refer to Appendix A. Item Number

Quantity

3 5 15 26 47 52 53

2 1 3 1 2 3 9

Standard or Production Part Production Standard Standard Production Production Standard Standard

WP3: Control fittings 3.1 In the assembly station: the following switching fittings were included: gate valve (x1), ball valve (x6), non-return valve (x1). Shut-off valve (x5) were used as adjustment fittings. 3.2 Switching fittings enable a pipe to be either completely shut off or fully open whereas adjustment fittings allow the flow quantity to be regulated in fine increments. 3.3 The explanation of the standard designation of the following Valve DIN 3356 – 15 PN 16 – 2A02A: -

DIN 3356 = Shut off valve 15 = Nominal diameter of pipe PN16 = Maximum nominal pressure that the pipe can withstand 2 = Component is made of cast iron A = Type of flow is direct flow, with flange connection 02 = Design and equipment confirming to type code 02 A = EN-GJL-250 which is a grey cast iron

3.4 The control fitting shown in Figure is a gate valve is located in Section B of the assembly station (Figure) When the gate valve is open, the wedge is fully withdrawn from the flow, allowing

the fluid to pass through with a low flow resistance. In contrast, when the gate valve is close, the wedge completely blocks the fluid from flowing. This control fitting is often used in the petroleum industry (Albert, 1990).

Figure 5: Cross-sectional diagram of a gate valve 1) 2) 3) 4) 5)

Hand wheel Stem Yoke sleeve Bolted yoke Wedge

3.5 Figure shows a non-return valve. This control fitting is located in Section C of the assembly station to avoid a reverse flow. It is usually used when process systems have varying pressures (Anon, 2019). It is also commonly used in domestic heating systems to prevent vertical convection.

Figure 6: Cross-sectional diagram of a non-return valve 1) 2) 3) 4) 5) 6) 7) 8)

Spring Packing Sealing disc Bonnet Spring seat Nut Body Cover

3.6 Condensate drains are required in piping systems carrying steam. It is commonly found at the lowest point in a piping system.

Figure 7: Cross-sectional diagram of a condensate drain 1) 2) 3) 4) 5) 6) 7) 8) 9)

Valve Body Dirt Trap Main body Cover Body Steam condensate inlet Outlet aperture Air condensate drain

WP 4: Symbols and information Table 4: A table with the explanation of symbols DN 15 PN16 lw t S 185 NBK

DN stands for nominal diameter. The number, 15, shows the magnitude of the DN. PN stands for nominal pressure and the value shows the maximum positive pressure with the unit bar at which a component can operate at 20°C. Bore Wall thickness Material designation (Steel construction, minimum yield stress Re = 185 N/mm2 Seamless cold-drawn pipes, normalised Gate valve with manual operation

Gate valve

Shut-off valve

Two-way valve

Non-return valve

Inspection glass

Pressure gauge

Dirt trap

Condensate drain

Hose fitting with rapid action coupling

7.Conclusion This experiment was successful as users were able to develop practical skills after a hands-on experience with the re-assembly and disassembly of piping system. It also allowed the users to familiarize with the function of common industrials pipes and fittings. The WPs completed helped in the understanding of technical drawings and the importance of planning of piping and system installations according to each specification. It is also essential to carry out leak test for safety reasons. There was no leakage observed in 5 minutes. However, this is not long enough to prove that the piping system has completely no leakage. Thus, the leak test should be left for an hour as suggested. 8.References Amin, Z., 2019. What Is A Piping System. [online] Cheresources.com Community. Available from: https://www.cheresources.com/invision/blog/52/entry-250-what-is-a-piping-system/ [Accessed 19 Mar. 2019]. Anon, 2019. Pipe Fittings Applications,Categories of Pipe Fittings,Applications of Pipe Fittings,Industrial Pipe Fittings Application. [online] Thepipefittings.com. Available from: http://www.thepipefittings.com/pipe-fittings-applications.html [Accessed 19 Mar. 2019]. Anon, 2019. [online] Who.int. Available from: https://www.who.int/water_sanitation_health/hygiene/plumbing10.pdf [Accessed 19 Mar. 2019]. Eavas, J., 2018. Common PVC Pipe Used for Irrigation Systems. [online] Pvcfittingsonline.com. Available from: https://www.pvcfittingsonline.com/resource-center/common-pvc-pipe-used-forirrigation-systems/ [Accessed 19 Mar. 2019]. Anon., (2017). Low water pressure. [online] Available at: https://www.affinitywater.co.uk/waterpressure-low-pressure.aspx [Accessed 18 Mar. 2019]. Smith, p. 2007. Chapter 7: Inspection and Testing. In pp. 191–208.

Curry, B., 2003. [online] Copperplumbing.org.uk. Available from: https://copperplumbing.org.uk/sites/default/files/content_attachments/pressure-testing-pipingsystems_1.pdf [Accessed 18 Mar. 2019]. Anon, 2019. Piping Valve Classifications - The Process Piping. [online] The Process Piping. Available from: https://www.theprocesspiping.com/piping-valve-classifications/ [Accessed 19 Mar. 2019].

Appendix

Figure 8: The 2 sections of piping system that were disassembled and re-assembled

Figure 9: HL960 assembly station drawing Table 5: Parts list for general drawing of HL960 assembly station

Item 1 2 3 4 5 6 7 8

Quant Unit Name ity Ball valve, 1/2" with cutting 2 x ring fitting and hose fitting. lw = 20 mm Ball valve, 1/2" with cutting 2 x ring fitting 2 x Ball valve with flange 5 x Shut-off valve 1 x Gate valve 1 x Non-return valve Dummy disc for flange 1 x connection Spectacle blind for 1 x flange connection

Dimensions

Standard / Catalogue

DN 15/ PN 16

DIN 3357

DN 15/ PN 16

DIN 3357

DN 25/ PN 16 DN 15/ PN 16 DN 40/ PN 16 DN 15/ PN 16

DIN 3357 DIN 3356 EN 12288 DIN 3356

DN 15

EN 1092-1

DN 15 / PN 10-40

EN 1092-1

9

1

x

Pressure vessel with pressure DN 15 gauge and steel flange

10 11 12 13 14

1 1 1

x x x

Inspection glass with flange DN 15/ PN 16 Dirt trap with flange DN 15/ PN 16 Condensate drain with flange DN 15/ PN 40

15

3

x

T-piece with steel flange

DN 25

16

1

x

T-piece with reducing fitting and steel flange

DN 15 - 25

17

2

x

T-piece with steel flange

DN 15

18 19

3 1

x x

DN 15 DN 15

20

1

x

21 22 23 24

1 1 2

x x x

T cutting ring fitting Angled cutting ring fitting Threaded flange with threaded fitting lw = 13 mm Flange with adapter Rapid action coupling Screw-in fitting

25

1

x

26

1

x

27

1

x

1

x

Pipe L = 473 mm with steel flange Pipe L = 198 mm with steel flange Pipe L = 198 mm with steel flange

DN 15/ PN 16/ G 1/2" DN 15 G 1/2" - 18 DN 25 DN 25 DN 25

DIN 28011 DIN 2982 EN 1092-1 DIN 2440 See catalogue DIN 32021/f1 See catalogue

EN 1092-1 DIN 2615 EN 10255 EN 1092-1 DIN 2615 DIN 2616 EN 1092-1 DIN 2615 DIN 2353 DIN 2353 DIN 2566 DIN 2566 See catalogue DIN 2353 EN 1092-1 EN 10255 EN 1092-1 EN 10255 EN 1092-1 EN 10255

28 29 30

Pipe L = 848 mm with steel flange

DN 15

EN 10255 EN 1092-1

Pipe L = 464 mm with steel flange Pipe L = 298 mm with steel flange Pipe L = 357 mm with steel flange Pipe L = 269 mm with steel flange

31

1

x

DN 15

32

1

x

33

1

x

34

1

x

35

1

x

Pipe extension with steel flange

DN 15 - DN 25

37

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

38

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

39

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

40

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

41

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

42

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

43

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

44

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

45

1

x

Pipe - S185

D = 18 mm t = 1.5 mm

DN 15 DN 15 DN 15

EN 10255 EN 1092-1 EN 10255 EN 1092-1 EN 10255 EN 1092-1 EN 10255 EN 1092-1 EN 10255 DIN 2616 EN 1092-1

36 EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK DIN 2391-C Delivery condition NBK EN 10305-1 Delivery condition NBK EN 10305-1 Delivery condition NBK

46 EN 1092-1 DIN 2516 DIN 2605 DIN 2616 48 1 x DN 15 - DN 25 DIN 2695 EN 1092-1 DIN 2605 49 2 x Bend 90° with steel flange DN 15 EN 1092-1 Note: the seals are not included in this parts list. No lengths can be specified for items 37 - 45 in the parts list. These pipe sections are cut to size and fitted directly during assembly. 47

2

x

Bend 90° with extension and steel flange Bend 90° with extension and steel flange

DN 25 - DN 40...