TNPSC Recruitment to Senior Assistant Director of Boilers Post

 

Recruitment for Boiler Inspectors

TNPSC Exam for the Post of Senior Assistant Director of Boilers in Directorate of Boilers, Tamil Nadu

 
Tamil Nadu Public Service Commission has issued Notification on 15.05.2024 for Combined Technical Services Examination, 2024 (Degree/PG Degree Level - Interview Posts) for various posts in various departments of Government of Tamil Nadu that include Senior Assistant Director of Boilers in Directorate of Boilers, Tamil Nadu (Post Code - 1700, 4 vacancies).

Academic and Professional Eligibility for the post of Senior Assistant Director of Boilers:

1. Educational Qualification: BE/B.Tech. (Mechanical Engineering) or AMIE (Mechanical Engineering).

2. Experience: Must have undergone training as a practical Engineer in the design, construction, operation or maintenance of boilers for a period of not less than two years (as on 15.05.2024) during which should have held responsible charge of a Steam Generation Plant or a Boiler Plant comprising of a battery of Boilers, the total capacity of either plant being not less than 15,000 Lbs/Hr.

NOTES:

1. Engineers with a degree in BE/B.Tech. (Mechanical Engineering) or AMIE (Mechanical Engineering) and with practical experience for not less than two years in Design or Construction or Operation or Maintenance in a Steam Generation Plant comprising a single installed boiler with a steaming capacity of not less than 15,000 pounds per hour (or 7 TPH) or in a Boiler Plant comprising a battery of installed boilers (more than one connected installed boilers) with a combined steaming capacity of not less than 15,000 pounds per hour (or 7 TPH) are eligible to apply for the post of Senior Assistant Director of Boilers.

2.  Engineers with degree in branches other than Mechanical Engineering are not eligible to apply for this post. (For example, graduates in Production Engineering, Power Plant Engineering and Metallurgical Engineering are not eligible.)

3.  Candidates with experience in a Steam Generation Plant comprising a single installed boiler with a steaming capacity of less than 15,000 pounds per hour (or 7 Tonnes per hour)  are not eligible.

4.  Candidates with experience in a Boiler Plant comprising a battery of installed boilers (more than one connected installed boilers) with a combined steaming capacity of less than15,000 pounds per hour (or 7 TPH) are not eligible.

5. Candidates with experience in Design or Manufacturing of Boilers are not eligible if they are not employed in a Steam Generation Plant comprising a single installed boiler with a steaming capacity of not less than 15,000 pounds per hour (or 7 TPH) or in a Boiler Plant comprising a battery of installed boilers (more than one connected installed boilers) with a  combined steaming capacity of not less than 15,000 pounds per hour (or 7 TPH).

For other details, kindly refer to the Notification of TNPSC (Click on the link below to download the Notification).

Download Link for Notification - TNPSC CTS Exam 2024 Notification

The Link for filing online application in TNPSC Portal -  https://www.tnpsc.gov.in/English/Notification.aspx

Last Date for submission of online application in TNPSC Portal - 14.06.2024.

Revised Annual Inspection Fees - IBR 385A

Fee for Annual Inspection of boilers in use, has been so far determined by the State Governments in India in accordance with powers vested by Boilers Act under Section 29, leading to different Fees structures in different States. After the recent amendment to the Boilers Act, the power has been shifted to Central Boilers Board, New Delhi. Now annual inspection fees for boilers in use, have been rendered uniform throughout India for all States by means of the addition of Regulation 385A to Indian Boiler Regulations. All boiler owners are requested to note the change in the fee when they remit the annual inspection fee in future.

Annual Inspection Fee Structure prescribed in Regulation 385A has been reproduced below for ready reference.

SL.NO.   BOILER RATING (square metre)         FEE (Rs)

1.         For SIB boilers                                                          1,000

2.         Not exceeding 10                                                       1,600

3.         Exceeding 10 but not exceeding 30                           2,100

4.         Exceeding 30 but not exceeding 50                           2,400

5.         Exceeding 50 but not exceeding 70                           2,700

6.         Exceeding 70 but not exceeding 90                           3,400

7.         Exceeding 90 but not exceeding 110                         4,000

8.         Exceeding 110 but not exceeding 200                       4,500

9.         Exceeding 200 but not exceeding 400                       5,000

10.       Exceeding 400 but not exceeding 600                       5,800

11.       Exceeding 600 but not exceeding 800                       6,300

12.       Exceeding 800 but not exceeding 1000                     7,100

13.       Exceeding 1000 but not exceeding 1200                   8,400

14.       Exceeding 1200 but not exceeding 1400                   9,500

15.       Exceeding 1400 but not exceeding 1600                   11,100

16.       Exceeding 1600 but not exceeding 1800                   11,900

17.       Exceeding 1800 but not exceeding 2000                   13,200

18.       Exceeding 2000 but not exceeding 2200                   14,300

19.       Exceeding 2200 but not exceeding 2400                   15,800

20.       Exceeding 2400 but not exceeding 2600                   16,600

21.       Exceeding 2600 but not exceeding 2800                   18,000

22.       Exceeding 2800 but not exceeding 3000                   19,000

Above 3000 square metre Rating, for every 200 square metre or part thereof an additional fee of Rs.500 shall be charged.

*** End of Table ***

HOW TO COMPUTE ANNUAL INSPECTION FEE FOR YOUR BOILER

1. Find out the Rating of your boiler. It will be available in the Provisional Order (Form V) or Certificate (Form VI) as the case may be, issued to your boiler by the Boiler Directorate.

2. If the Rating is available in the above table, read the Fee in the last column in the appropriate row of the table. For an example, if the Rating is 201, Fee is Rs.5000 corresponding to the row number 9. Or if the Rating is 1000, Fee is Rs.7100 corresponding to the row number 12.

3. If the Rating exceeds 3000 square metre, then compute the Fee in the following method. Deduct 3000 from the Rating. Divide the balance by 200. Find the quotient and the remainder. Now the Fee = 19500 + Quotient * 500 if the remainder is not zero, and the Fee = 19000 + Quotient * 500 if the remainder is zero.

For example, suppose the Rating is 8750 square metre. Quotient for (8750 - 3000) / 200 is 28. Remainder is non-zero. Therefore, Fee = 19500 + 28 * 500 = 33500. So, Annual Inspection Fee for your boiler is Rs.33,500.

Let us see another example. Suppose the Rating is 34,200 square metre. Quotient for (34200 - 3000) / 200 is 156. Remainder is zero. Therefore, Fee = 19000 + 156 * 500 = 97000. So, Annual Inspection Fee for your boiler is Rs.97,000.

Essentials of Physical Metallurgy for Boiler Industry - Part 4/4: Fundamentals of Welding Metallurgy

 CHAPTER 6. WELDING

            Welding is characterized by a very high peak temperature, above 1500°C, but retained only for a very short time. Therefore, there will be no appreciable grain growth unlike in the case of casting. The plate or pipe parts being joined act like a huge sink of heat resulting in a drastic cooling of fused weld pool of little volume. Such a rapid cooling rate is of the biggest concern during welding because it has a potential of adversely affecting the microstructure of not only the solidified weld metal but also the HAZ of the base metal.

6.1 Microstructures of Weld & HAZ

            The microstructure of the weld metal will be noticeably different from that of the base metal or HAZ because it represents the as-solidified molten metal pool under rapid rate of cooling. See fig. 6.1. Typical microstructure of the weld metal of low carbon and low alloy steels consists of ferrite in different shapes and locations and bainite. They are very fine-grained generally.

            HAZ is that portion of the base metal lying next to the fusion line of weld, which had not melted but whose microstructure and hence mechanical properties have been altered by the heat of welding. Near the fusion line the peak temperature of HAZ can reach 1400°C. Grain growth and coarsening occur in this region. See fig. 6.2.

           Because of the relatively high cooling rate and large grain size, acicular, rather than blocky, ferrite is formed at boundaries of large grains of fine-pearlite or bainite. Due to coarsened grains, under very high cooling rate, this region has the potential of getting transformed into martensite.

6.2 Residual Stress

6.2.1 Development

            Let us assume that during welding, a small band of base metal adjacent to fusion zone reach an average temperature of 900°C and the rest of the base metal is at an average temperature which is slightly more than the room temperature. The heated band of base metal adjacent to the weld tries to expand, which is restrained by the adjacent large mass of relatively cold portion of base metal. This leads to a compressive stress induced in the heated band. Since a temperature differential of 100-150°C is sufficient to induce stresses of such a high magnitude as to exceed the yield strength of the steel, the heated band soon starts flowing plastically during welding.

            Now after welding, the heated band begins to cool and shrink, which is again restrained by the adjacent large mass of base metal. This leads to a tensile stress induced in the heated band. The large thermal gradient during the heating-cooling cycle of welding, thus, leads to the development of internal stress, called the residual stress.

            The nature and distribution of the residual stress are complicated and difficult to be evaluated. It exists along, across and through-thickness of the weld and base metal, i.e., in a triaxial state. It is comprised of tensile and compressive stresses in equilibrium. It is generally of the order of yield strength of the material at its peak value.

Essentials of Physical Metallurgy for Boiler Industry - Part 3/4 - An Introduction to Alloy Steels & Stainless Steels

CHAPTER 5. Cr-Mo FERRITIC STEELS & Cr-Ni AUSTENITIC STEELS

5.1 Alloy Steels

            The so-called plain carbon steel is apt to be fancy to the extent of containing measurable quantities of at least half a dozen other elements like Mn,Si, etc. each of which has its own individual effects on the properties of the steel. But when alloying elements are added on a specific purpose and in such a quantity that the properties of the steel are significantly altered, then the steel is called alloy steel.

5.2 Ferritic and Austenitic Steels

            Carbon steels exhibit poor creep properties and are, therefore, not normally used at metal temperatures beyond 450°C. Addition of Mo in ½-1% increases the resistance of the steel to deformation at elevated temperatures due to the formation of its carbides. But these carbides are not stable at  elevated temperatures for long time.

            Addition of Cr in 1-2¼% to Mo steels stabilizes these carbides. Cr-Mo steels in various compositions like 1Cr-½Mo, 1¼Cr-½Mo and 2¼Cr-1Mo are found to exhibit good creep properties. These steels are used over a wide range of service metal temperatures i.e., from 450-575°C.

            When Cr is added in excess of 11%, it increases the resistance of the steel to corrosion. Addition of Ni depresses the LCT of the steel from 723°C to lower temperatures – 8% Ni ensures that both LCT & UCT are depressed to temperatures lower than room temperature so that the steel is fully austenitic at room temperature. 18%Cr-8%Ni steels are therefore known as austenitic stainless steels, which also exhibit good creep properties at temperatures as high as 600°C.

Essentials of Physical Metallurgy for Boiler Industry - Part 2/4: Fundamentals of Heat Treatment

CHAPTER 4. HEAT TREATMENT

4.1 Recrystallization

Crystalline grains of solid steel try to reduce their surface energy to go to a more stable form. As a result, they try to reduce their outer surface. This explains their tendency to assume equiaxial shape and to grow.

These fundamental recrystallizing forces, which promote spheroidising and grain growth are present at all temperatures but the forces are greater as the crystals become finer and depart further from spherical shape. Opposed to these recrystallizing forces are strength and rigidity of the material, which will drop as the material is heated. Crystals of a material will begin to merge and grow at a particular temperature, known as recrystallization temperature.

4.2 Annealing

Also known as full annealing, it consists of heating the steel to the austenitising temperature (UCT + 20-30 °C) and soaking it there for a definite time and then cooling it back slowly to room temperature, usually in the furnace.

Let us consider a 0.25% carbon steel valve casting, conforming to the specification SA216 WCA, solidifying in the mould from liquid state. Since it passes through very high temperatures, i.e., 1400-1100ºC for sufficient time, grains get coarsened. The coarse-grained austenite at UCT is transformed into coarse-grained ferrite and pearlite at LCT. Such a coarse grained casting is brittle and weak, which can be, however, made strong and ductile by refining the grains by annealing. See fig.4.4.

The casting is reheated to its austenitising temperature. UCT of steel can be computed by assuming the UCT curve to be a straight line: 910 – [(910-723) × 0.25/0.8] ≈ 850ºC. Add 30ºC to get 880ºC as the austenitising temperature. Since diffusion rate is dependent on the surface area of a grain, coarse grains, due to their less surface area, dissolve very slowly. Therefore, austenitising temperature is selected around 900ºC. For the same reason, soaking time at this temperature is also unusually longer – 3 - 6 hours are quite common. Then the casting is slowly cooled through the transformation range between UCT and LCT in the furnace with fuel cut off. Since the microstructure of the casting does not change below LCT, casting is usually taken out of the furnace after 500°C. Thus a strong and ductile casting with fine grained structure at room temperature is obtained by annealing. Annealing also reduces the hardness of the casting.