8/6/2015

Internship Report Gas Geyser Thermostat work shop

TESLA.PV ISLAMABAD I-10/3 STREET 6

1 ABSTRACT: ................................................................................................................................................. 1

2 INTRODUCTION: ........................................................................................................................................ 1

3 STATIONS: ................................................................................................................................................. 1

3.1 MACHINE WORKSHOP: ....................................................................................................................................... 1 3.1.1 Filing: ....................................................................................................................................................... 1 3.1.2 Drilling:..................................................................................................................................................... 1 3.1.3 Threading: ................................................................................................................................................ 2 3.1.4 Washing: .................................................................................................................................................. 3 3.1.5 Pressing: ................................................................................................................................................... 3 3.1.6 Rotor: ....................................................................................................................................................... 3 3.1.7 Rear seat filing: ........................................................................................................................................ 3

3.2 N OPERATION: .................................................................................................................................................. 3 3.2.1 Ring Spring: .............................................................................................................................................. 3 3.2.2 H Ring: ...................................................................................................................................................... 3 3.2.3 Ring Spring: .............................................................................................................................................. 3 3.2.4 N spring plus aluminum button plus aluminum pin: ................................................................................ 3 3.2.5 Pressure disc: ........................................................................................................................................... 3 3.2.6 Copper disc: .............................................................................................................................................. 3 3.2.7 Sealing plate plus MS button: .................................................................................................................. 3 3.2.8 Slider pin and sleeve: ............................................................................................................................... 4 3.2.9 Adjuster plate: ......................................................................................................................................... 4 3.2.10 Sensor (thermistor) .............................................................................................................................. 4 3.2.11 Adjuster bolt and nut: .......................................................................................................................... 4 3.2.12 Problems and solutions: ...................................................................................................................... 4

3.3 FRONT SEAT AND FRONT PLATE: ........................................................................................................................... 4 3.3.1 Front seat, seal: ....................................................................................................................................... 4 3.3.2 Glass filter wool: ...................................................................................................................................... 4 3.3.3 Front seat spring: ..................................................................................................................................... 4 3.3.4 Main gasket: ............................................................................................................................................ 4 3.3.5 Front seat cover: ...................................................................................................................................... 4

3.4 FINAL ASSEMBLY: .............................................................................................................................................. 4 3.4.1 Screw:....................................................................................................................................................... 5 3.4.2 Adjuster valve: ......................................................................................................................................... 5 3.4.3 Rotor operation: ....................................................................................................................................... 5 3.4.4 Pilot manual: ............................................................................................................................................ 5

3.5 SOLENOID CELL: ................................................................................................................................................ 5 3.6 RETEST: ........................................................................................................................................................... 5

3.6.1 Adjuster Cup: ............................................................................................................................................ 5 3.6.2 Abbreviations used for defects: ............................................................................................................... 5

3.7 GAS GEYSER THERMOSTAT PACKING: ..................................................................................................................... 6 3.7.1 Thermostat plastic packing: ..................................................................................................................... 6 3.7.2 Adjuster nut: ............................................................................................................................................ 6 3.7.3 In out seals: .............................................................................................................................................. 6 3.7.4 Main knob: ............................................................................................................................................... 6 3.7.5 Rotor knob: .............................................................................................................................................. 6 3.7.6 Connector seal: ........................................................................................................................................ 6

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1 Abstract: his report covers the details of the processes taking place at the gas geyser thermostat workshop.

2 Introduction: The gas geyser thermostat workshop is one of the many workshops located at Tesla.pv. As its name suggests, this workshop is intended for the production of thermostats assemblies. I work in this workshop for two days and produced below is what I learnt.

3 Stations: A total of seven stations are present in the workshop details of which are below:

1. Machine workshop. 2. N operation. 3. Front seat and front plate. 4. Final assembly. 5. Solenoid cell. 6. Retest. 7. Packing.

Details of these are below.

3.1 Machine workshop: 3.1.1 Filing: The process starts with thermostat casting, which comes from Lahore. The thermostat castings undergo slight filing to remove any nicks and burs.

3.1.2 Drilling: There are slight sports on the casting, which indicate the places to be drilled. These spots are drilled using the drill machine.

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2 | P a g e 3.1.3 Threading: On the castings there are certain holes which need to be threaded. Drilling machine modified by a threading assembly is intended to make these threads.

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3.1.4 Washing: In this process, kerosene oil along with water is used at a high-pressure to wash this castings.

3.1.5 Pressing: Using a hand press machine, plug gasket, side hole plug, inlet filter, outlet washer our pressed at the relevant positions.

3.1.6 Rotor: Like the thermostat casting, the rotor casting also comes from Lahore. But it needs machining, which is done on the lathe machine.

3.1.7 Rear seat filing: The rear seat is filed using a lathe machine. This operation is called rear seat operation or N operation.

3.2 N operation: N operation means all those operations which take place on the rear seat. These operations are explained below, these operations take place in sequence and are placed one above the other:

3.2.1 Ring Spring: Ring Spring is made of an elastic wire.

3.2.2 H Ring: It is called so because a figure like the alphabet H is engraved in it.

3.2.3 Ring Spring: Same as above.

3.2.4 N spring plus aluminum button plus aluminum pin: It’s called N Spring because of its shape. They are placed at the relevant places.

3.2.5 Pressure disc: 3.2.6 Copper disc: 3.2.7 Sealing plate plus MS button: These two are pressed.

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After these steps apply grease to bolts and tighten using a gas pressure adjuster.

3.2.8 Slider pin and sleeve: 3.2.9 Adjuster plate: 3.2.10 Sensor (thermistor) 3.2.11 Adjuster bolt and nut: When we turn the main adjusting knob actually we are turning this adjuster bolt.

Its angle should be between 35 to 45°.

3.2.12 Problems and solutions: problem cause

Angle not correct. Change then N Spring. Rear seat leak. Again, press it. No off on sound. H Spring change.

3.3 Front seat and front plate: Following operations take place in sequence, in this station:

3.3.1 Front seat, seal: Front seat and its seal are meant to overlap each other, accurately, if not, they are filed and compared to do so.

3.3.2 Glass filter wool: The purpose of this wool is to prevent any solid particles from entering into the thermostat body.

3.3.3 Front seat spring: 3.3.4 Main gasket: This is to ensure the sealing of the main thermostat body.

3.3.5 Front seat cover: 3.4 Final assembly: As its name suggests, here the thermostat is made ready to be tested. A number of operations take place here. All these operations take place on the top plate:

5 | P a g e 3.4.1 Screw: 3.4.2 Adjuster valve: Adjuster valve is mounted into its correct place. Its purpose is to control the flame. Greece is also used to produce is in its rotation.

3.4.3 Rotor operation: Black grease is used for the rotor. Rotor Spring plus washer is mounted on its top upon which the top plate is screwed. The rotor should rotate about 180°.

3.4.4 Pilot manual1: Pilot manual plus gasket are pressed intact by Hammer.

3.5 Solenoid cell: The solenoid cell is the heart of this thermostat. The solenoid cell is made in China, grease is applied to it and it is inserted into its correct place in the thermostat casting.

3.6 Retest: The whole assembly is retested using the flame for any leakage or any other fault. It’s then using a potential difference to take place of the thermocouple. Solenoid cell and the thermocouple are internally linked. They use their own notation to denote what the defect is.

3.6.1 Adjuster Cup: This cup is used to prevent from adjusting the pilot adjuster knob.

3.6.2 Abbreviations used for defects: abbreviations used What they denote

PML Pilot manual leaked HA High angle LA Low angle HC H Spring change RSL Rear seat leak FSL Front seat leak

1 , the pilot manual is also manufactured in this workshop. It consists of a few washers, rubber sealing, springs, mounted on a single aluminum nail like structure.

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RL Rotor leak BD Burner direct2

After this, these pieces with abbreviations written on them are sent back to the respective sections because assembling the thermostats is a very sensitive task. So mostly problems come and there are more assembled parts which need rework than correct ones.

3.7 Gas geyser thermostat packing: Gas geyser thermostats are packed with in groups of five by casing. And per carton is 25 thermostats that is five casings per carton.

3.7.1 Thermostat plastic packing: Using heat the thermostat is packed using a plastic sheet.

3.7.2 Adjuster nut: 3.7.3 In out seals: They’re made of rubber.

3.7.4 Main knob: They’re made of plastic. They are the knobs which we rotate.

3.7.5 Rotor knob: It should rotate 180°.

3.7.6 Connector seal:

After these operations, the thermostats are stamped indicating the necessary precautions, and the company logo.

4 Accompanying parts: Apart from these, using the auto lathe machine and the CNC machine, following parts are also made in the other section of workshop:

2 In this situation, the burner keeps burning no matter we turn it on or off.

7 | P a g e 4.1 Sleeve pin: Made on auto lathe machine.

4.2 Adjuster nut: Made on auto lathe machine.

4.3 Outlet washer: Made on auto lathe machine.

4.4 CNC pressure disc: On CNC machine.

4.5 Aluminum button: On auto lathe machine.

4.6 Adjuster cup: On auto lathe machine.

Pressure disc Outlet washer

Adjuster nut

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5 Conclusion: In short, the workshop was create. The QC was very good. Every step and every measure is well calculated. Owing to sensitivity of this product, mostly most of the parts show faults, these faulty parts are resent for rework.

Sleeve pin Aluminum button

MS button

Sealing plate