Hazardous Zones Protection Techniques for Oil & Gas Industry

 Different protection techniques are used to address the hazardous zones :-

		ZONES
Ex d	Flameproof (Explosion proof) Enclosure	1, 2
Ex e	Increased Safety	1, 2
Ex ia	Intrinsically Safe	0, 1, 2
Ex ib	Intrinsically Safe	1, 2
Ex o	Oil Immersion	2
Ex p	Pressurized Apparatus (Purged Apparatus)	1, 2
Ex q	Powder Filling (Sand Filling)	2
Ex m	Encapsulation	1, 2
Ex n or Ex N	Non incentive or/and normally no sparking circuits	2

Explosion proof Gland and Difference between Explosion prrof and Double compression glands

 EXPLOSION PROOF GLANDS :-

Double compression explosion proof Glands are used in electrical equipment's for gland work of armored cable in compressor area,  glands usually have following construction features:-

1.Double Compression (Explosion proof Cable Glands-I,IIA,IIB)  

2.Material Brass (IS 319) -Standard. (AL/Mild Steel/SS. also available )

3.Threads ET"/BSC-Standards (In PG/Metric/NPT/BSP also available)

4.Sealing Ring Neoprene  

 Protection Class IP 66 as per IS 13947  

Pic Shows the Explosion proof Gland

Application Generally used in flammable Gas/ Vapour area (Gas I,IIA,IIB)  

EXPLOSION PROOF GLANDS PARTS:-

11. CHECK NUT 6 ARMOUR CLAMPING RING

22. WASHER 7 MAIN GLAND BODY

  3. NIPPLE ENTRY PART 8 NEOPRENE OUTER RUBBER

44. NEOPRENE INNER RUBBER 9 SKID WASHER

55. ARMOUR CLAMPING CONE 10 GLAND COVER

Main Difference between Explosion proof and Double compression glands is that Flameproof glands doesn't

Power Scenario in India action required; Electricity improvement methods in India

ACTIONS TO BE TAKEN FOR IMPROVING POWER SCENARIO IN INDIA

àEnvironment clearances should be faster for producing more coal.

àCERC should take corrective steps to raise electricity tariff whenever there is requirement without any discussion with State electricity boards and also RBI should intervene and say Banks not to lend State electricity boards.

àCoal India should improve connectivity so that coal will reach at required location as earlier as possible as coal is lying at locations without facility of transportation.

àMore efforts required to get Natural gas from Turkmenistan as earlier as possible.

àIndia should more concentrate on Renewable energy sources as they have huge prospect in India. India has limited Energy sources such as Coal, Oil, and Natural Gas. But More efforts are required to for Renewable energy sources so that India get free from limited energy sources. As India has laid foundation for the same as India plans to source 3% of it total electricity consumption from solar energy by 2022 and has been taking notable steps to increase solar power capacity. 

Factors Influencing Lower Utilization of Power plants

CAUSES OF LOWER UTILIZATION OF POWER PLANTS:-

àIndia has about 42,000 MW Installed capacities but can’t get commissioned due to lack of availability of fuel. Nearly 15,000 MW of gas-based power plants are under shutdown due to Shortage of Gas. There are more than 50 gas-fired power plants in India, but most of them are facing shortage of fuel. This is due to fall in Gas from RIL KG Basin. It’s not economical to run these power plants at Imported R-LNG which is very costly.

àCoal scam hits India in March 2012, which shows that it had impacted India big way and leads to loss to India as much as 1.9 Lakh Crore. During Scam it has been find out that out of the 195 coal blocks allocated between 1993 and 2008, production had begun in only 30 blocks. Out of 195 blocks, 160, were allotted by the UPA government between 2004 and 2008, so far production has begun only in two. Most of allocation was done to  Power and Steel companies but they failed completely They were given coal blocks only taking into mind that this will leads denationalize coal production and will leads to effective and effective mining of coal but all get in Vain.

àEnvironment policies on clearance of mining also added to more difficulties as new norms set under Environment Jairam Ramesh were not met by most of companies.

àCoal-fired power plants capacity in India has by 10% every year between 2008 and 2012 but coal production increased by just 4% annually. This gap has led to an increase of coal imports for the power sector by 300% over the period. In the meanwhile there was also a significant rise in international coal prices that will leads to threatening the country’s energy security.

à Power distribution companies are in losses as State governments are reluctant to increase tariffs and which will lead to power distribution co.s are getting defaulted to power producers which will leads to burden on Banks as they had taken loans from banks.

India Power generation Capacity

POWER SCENARIO OF INDIA

Indian economy is going in strong way. The way Indian Economy is growing India is way lagging behind power demand requirement rising every year.

In India there are still people living in Villages without power also where power is available but there are so much power cuts.

If we accept that Indian GDP will grow at 9% then 20,000 MW Power required every year for the same.

Although total Installed Capacity of Power plants as on 31^st Jan 2014 was about 2,34,601.94 MW as per CERC.

Coal Power Plants contributes about 59% of the above installed Capacity.

Gas Power Plants contributes about 9% of the above Installed capacity.

Hydro Power Plants contributes about 17.5% of above Installed capacity.

Nuclear Power Plants contributes about 2%.

RES (MNRE) i.e. Renewable Energy Sources contributes 12%.

Oil Power plants contributes about 0.5%.

Electrical Explosion proof Equipment's Standards & Classification

Flameproof Material Standards All Flameproof Electrical Equipment's are Designed and Constructed in Accordance with following Standards:-

àIS 2148-1981

àIEC 60079-1

àIS 13346-1992

SELECTION OF ELECTRICAL EQUIPMENT :-

A No. of Logical steps are involved in selection of Electrical Equipment for Hazardous Area:-

Step 1:- Identify its Gas Group & Temperature Class

Step 2:- Identify the Zone Area Zone 0, 1 or 2

Step 3:- Select the type of Protection Appropriate to the Zone

Step 4:- For the given type of protection select the equipment keeping in Mind the Gas Group and Temperature rating.

Step 5:- Depending upon whether the Equipment to be installed indoor or Outdoor ensure the correct IP for the equipment

GUIDE TO CERTIFICATION CODE:-

 Apparatus Marking normally include a certification code which include the following:-

Symbol for the type of protection. The apparatus group. The Temperature classification

Example:- Ex ‘d’ IIB T5 This indicates a unit having Flameproof protection of type ‘d’ Suitable for gas group IIA & IIB and having maximum temp. classification of 100 deg. Cel.

As per (T5) Some construction features of this flame proof AC motors are as follows :-

1. The flame proof construction for Exd.

2. The degree of protection is IP 55 for motor main enclosures.

3. The stator winding are of class F insulation and gives a large margin of safety in temperature rise and long service life.

4. The stator winding insulation is good in electrical and mechanical properties, moisture resistance and thermal stability.

5. A cylindrical shaft extension is furnished on motors that can be driven by coupling or spur gearing

6. The rotors are of cast- aluminum and dynamically balanced to make the motor operate smoothly with small vibration and the low noise.

7. Fans are made of cast iron, and have low windage loss.

8. The stator and rotor cores are laminated with high class electrical steel with high permeability and the low loss

Fuse Standards and their classification

For Low Power Fuses Electrical Standard IEC 60269 is followed.

There are 4 volumes for this standard.

è   1.For General Requirement

è   2.For fuses for industrial and commercial applications

è   3.Fuses for residential applications

è   4.Fuses to protect semiconductor devices.

IEC 60269-1 – Low-voltage fuses – Part 1: General requirements

IEC 60269-2 – Low-voltage fuses – Part 2: Fuses mainly for industrial application – Examples of standardized systems of fuses A to I

IEC 60269-3 – Low-voltage fuses – Part 3: Fuses mainly for household and similar applications – Examples of standardized systems of fuses A to F

IEC 60269-4 – Low-voltage fuses – Part 4: Supplementary requirements for fuse-links for the protection of semiconductor devices

IEC 60269-5 – Low-voltage fuses – Part 5: Guidance for the application of low-voltage fuses

IEC 60269-6 – Low-voltage fuses – Part 6: Supplementary requirements for fuse-links for the protection of solar photovoltaic energy systems

As per IEC standard

1.The replaceable element is called a fuse link 

2.The assembly of fuse link and fuse holder is called a fuse.

The standard identifies application categories which classify the time-current characteristic of each type of fuse. 

As clear from above fuse which clearly suggest gL- gG description let us study what does this means:-

The application category is a two-digit code.

The first letter is a if the fuse is for short-circuit protection only; an associated device must provide overload protection.

The first letter is g if the fuse is intended to operate even with currents as low as those that cause it to blow in one hour. These are considered general-purpose fuses for protection of wires.

The second letter indicates the type of equipment or system to be protected:

D – North American time-delay fuses for motor circuits, UL 248 fuses

G – General purpose protection of wires and cables

M – Motors

N – Conductors sized to North American practice, UL 248 fuses

PV – Solar photovoltaic arrays as per 60269-6

R, S – Rectifiers or semiconductors as per 60269-5

Tr – Transformers

Thus after studying we find that fuse can be used for applications General purpose protection of wires and cables.

Any fuses built to the IEC 60269 standard and carrying the same application category (for example, gG or aM) will have similar electrical characteristics, time-current characteristics, and power dissipation as any other, even if the fuses are made in the packages standardized to the earlier national standards. Fuses of the same application category can be substituted for each other provided the voltage rating of the circuit does not exceed the fuse rating.

The tests recommended on Fuses by IEC 60269 are:

1.Temperature rise & power dissipation test

2.Non-fusing & Fusing test

3.Verification of rated current test

4.Overload test

5.Verification of Time Current Characteristics and Gates