a) Basis of Preparation of Financial Statements
 
 The financial statements have been prepared and presented under the
 historical cost convention on the accrual basis of accounting following
 generally accepted accounting principles in India (GAAP) and comply
 with the Accounting Standards prescribed by the Companies (Accounting
 Standards) Rules, 2006 (as amended) and the relevant provisions of the
 Companies Act, 1956, to the extent applicable.
 
 b) Use of Estimates
 
 The preparation of the financial statements in conformity with GAAP
 requires management to make estimates and assumptions that affect the
 reported amounts of assets and liabilities and the disclosure of
 contingent liabilities as at the date of the financial statements, and
 reported amounts of income and expenses during the period. Actual
 results could differ from those estimates. Any changes in the estimates
 are adjusted prospectively.
 
 c) Revenue Recognition
 
 Revenue from sale of gas is recognised on transfer of risk and rewards
 of ownership to the customer and facility charge is recognised on
 accrual basis as per the terms of the contract with the customers.
 
 Income from fixed price long term construction contracts are recognised
 under the percentage of completion method with reference to the
 estimated overall profitability of the contract that is reassessed on a
 regular basis. Percentage of completion is ascertained on the basis of
 work completed under the contract and accepted by the customer based on
 the extent of work performed in accordance with the terms of the
 contract. Provision for expected loss is recognised immediately when it
 is probable that the total estimated contract costs will exceed total
 contract revenue.
 
 Contract revenue and contract costs associated with the long term
 construction contracts entered on or after 1 January 2011 are
 recognised as revenue and expenses respectively by reference to the
 stage of completion of the project at the balance sheet date. The stage
 of completion of project is determined by the proportion that contract
 costs incurred for work performed upto the balance sheet date bear to
 the estimated total contract costs. If total cost is estimated to
 exceed total contract revenue, the company provides for foreseeable
 loss.
 
 Revenue from cost plus contracts is recognised based on cost incurred
 on the project plus the mark up agreed with the customer.
 
 Interest is recognised on a time proportion basis. Income from dividend
 is recognised on declaration of dividend by the investee company.
 
 d) Fixed Assets
 
 Fixed assets are stated at cost of acquisition/revalued amounts less
 accumulated depreciation. Cost of acquisition includes taxes, duties,
 freight and other costs that are directly attributable to bringing
 assets to their working condition for their intended use.
 
 Spares that can be used only with particular items of plant and
 machinery and such usage is expected to be irregular are capitalised.
 
 The costs of Fixed Assets not ready for intended use before such date
 are disclosed as capital work-in-progress.
 
 e) Depreciation/Amortisation
 
 Tangible Assets
 
 Depreciation is provided under straight line method. The rates of
 depreciation prescribed by Schedule XIV of the Companies Act, 1956, are
 considered as minimum rates. If the management''s estimate of useful
 life of a fixed asset at the time of acquisition of the asset or the
 remaining useful life on a subsequent review is shorter than the useful
 life derived from the rate of depreciation prescribed in Schedule XIV,
 depreciation is provided at a higher rate based on the management''s
 estimate of the useful life/remaining useful life. Accordingly, certain
 components of Plant & Machinery are being depreciated at the rate of 10
 % and 6.91% that are higher than the corresponding rates prescribed in
 the aforesaid Schedule XIV.
 
 In case of revalued fixed assets, depreciation is provided as
 aforesaid, on the total value of fixed assets as appearing in the books
 of account after revaluation. Additional depreciation attributable to
 revalued amount is charged to the Profit and Loss Account. On disposal
 of a previously revalued item of fixed asset, the difference between
 the net disposal proceeds and the net book value is charged or credited
 to the Profit and Loss Account except that, to the extent such loss is
 related to an increase which was previously recorded as a credit to
 revaluation reserve and which has not been subsequently reversed or
 utilised, is charged directly to that account. The amount standing in
 revaluation reserve following the retirement or disposal of an asset,
 which relates to that asset is transferred to general reserve.
 
 Consideration for obtaining leasehold rights over land is being
 amortised over the period of the lease.
 
 Assets individually costing Rs. 5,000 or less are depreciated fully in
 the year of acquisition.
 
 Spares capitalised are being depreciated over the useful life/remaining
 useful life of the plant and machinery with which such spares can be
 used.
 
 Intangible Assets
 
 Computer software is amortised over its useful life of 5 years as
 estimated by management.
 
 Customer List arising on account of business acquisition is amortised
 over the period of 5 years, being the useful life as estimated by
 management.
 
 f) Impairment of Fixed Assets
 
 The carrying amounts of fixed assets and capital work in progress are
 reviewed at each Balance Sheet date in accordance with Accounting
 Standard 28 on Impairment of Assets prescribed by the Companies
 (Accounting Standards) Rules, 2006 (as amended), to determine whether
 there is any indication of impairment. If any such indication exists,
 the assets recoverable amounts are estimated at each reporting date. An
 impairment loss is recognised whenever the carrying amount of an asset
 or the cash generating unit of which it is a part exceeds the
 corresponding recoverable amount. Impairment losses are recognised in
 the Profit and Loss Account. An impairment loss is reversed if there
 has been a change in the estimates used to determine the recoverable
 amount. An impairment loss is reversed only to the extent that the
 assets carrying amount does not exceed the carrying amount that would
 have been determined net of depreciation or amortisation, if no
 impairment loss had been recognised.
 
 g) Borrowing Costs
 
 Borrowing costs directly attributable to acquisition or construction of
 those fixed assets which necessarily take a substantial period of time
 to get ready for their intended use are capitalised.
 
 h) Investments
 
 Long Term Investments are stated at cost. Provision is made for
 diminution, other than temporary, in the value of investments, wherever
 applicable. Current investments are stated at lower of cost and fair
 value.
 
 i) Inventories
 
 Raw materials, components, stores and spare parts are valued at lower
 of cost and net realisable value. Cost includes purchase price, duties
 and taxes (other than those subsequently recoverable by the Company
 from taxing authorities), freight inward and other expenditure in
 bringing inventories to present locations and conditions. In
 determining the cost, weighted average cost method is used. The
 carrying costs of raw materials, components and stores and spare parts
 are appropriately written down when there is a decline in replacement
 cost of such materials and the finished products in which they will be
 incorporated are expected to be sold below cost.
 
 Finished goods are valued at the lower of cost and net realisable
 value.  The comparison of cost and net realisable value is made on an
 item by item basis. Cost comprises of direct material and labour
 expenses and an appropriate portion of production overheads incurred in
 bringing the inventory to their present location and condition. Fixed
 production overheads are allocated on the basis of normal capacity of
 the production facilities.
 
 Excise duty liability is included in the valuation of year - end
 inventory of finished goods.
 
 Costs incurred on long term contracts representing general purpose item
 of inventories are disclosed as contract work in progress net of
 provision for loss.
 
 j) Leases
 
 Finance Leases
 
 Assets made available to customers under arrangements which are in the
 nature of finance lease are recognised as a receivable at the inception
 of the lease at an amount equal to the net investment in the lease or
 the fair value of the leased assets, whichever is lower. The excess of
 net investment in the lease/fair value of the leased asset, as the case
 may be, over the book value of the leased asset are recognised as gain
 in the Profit and Loss Account at the inception of the lease.  Lease
 rentals are apportioned between principal and interest based on a
 pattern reflecting a constant periodic return on the net investment of
 the lessor outstanding in respect of the finance lease. The lease
 rental amount received reduces the net investment in the lease and
 interest is recognised as revenue. Initial direct costs are recognised
 immediately in the Profit and Loss Account.
 
 Operating Leases
 
 Lease payments under operating leases are recognised as expense in the
 Profit and Loss Account on a straight line basis over the lease term.
 
 k) Research and Development
 
 Revenue expenditure on research and development is expensed in the year
 in which it is incurred and related capital expenditure is considered
 as addition to fixed assets.
 
 l) Employee Benefits
 
 The Company''s obligations towards various employee benefits have been
 recognised as follows:
 
 Short Term Benefits
 
 Cost of accumulating compensated absences that are expected to be
 availed within a period of 12 months from the period end are recognised
 when the employees render the service that increases their entitlement
 to future compensated absences. Cost is computed based on past trends
 and is not discounted.
 
 Cost of non-accumulating compensated absences is recognised when
 absences occur. Costs of other short term employee benefits are
 recognised on accrual basis based on the terms of employment contract
 and other relevant compensation policies followed by the Company.
 
 Post Employment Benefits
 
 - Monthly contributions to Provident Funds which are in the nature of
 defined contribution schemes are charged to Profit and Loss Account and
 deposited with the Provident Fund authorities on a monthly basis.
 
 Provident fund administered through Company''s trust for certain
 employees (in accordance with Provident Fund Regulation) are in the
 nature of defined benefit obligations with respect to the yearly
 interest guarantee. Annual charge is recognised based on actuarial
 valuation of the Company''s related obligation on the reporting date.
 Actuarial gains or losses for the year are recognised in the Profit and
 Loss Account as income or expenses.
 
 - Gratuity and superannuation schemes which are in the nature of
 defined benefit plans, excepting Plan B of Executive Staff Pension
 Fund, are administered by the Trustees. Annual contributions are
 recognised on the basis of actuarial valuation of related obligations
 and plan assets conducted by an external actuary appointed by the
 Company and are paid to the respective funds. Plan B of Executive Staff
 Pension Fund which is a defined contribution scheme for which the
 Trustees of the scheme have entrusted the administration of the related
 fund to the Life Insurance Corporation of India (LICI). The
 contributions are charged to Profit and Loss Account and deposited with
 LICI on a monthly basis.
 
 Other Long Term Benefits
 
 Cost of long term benefit by way of accumulating compensated absences
 that are expected to be availed after a period of 12 months from the
 period-end are recognised when the employees render the service that
 increases their entitlement to future compensated absences. Such costs
 are recognised based on actuarial valuation of related obligation on
 the reporting date. Actuarial gains and losses for the year are
 recognised in the profit and loss account as income or expense.
 
 Termination Benefits
 
 Costs of termination benefits have been recognised only when the
 Company has a present obligation as a result of a past event, it is
 probable that an outflow of resources will be required to settle such
 obligation and the amount of the obligation can be reliably estimated.
 
 m) Foreign Exchange Transactions
 
 Foreign exchange transactions are recorded at the exchange rate
 prevailing on the dates of the transactions. Year-end monetary assets
 and liabilities denominated in foreign currencies are translated at the
 year-end foreign exchange rates.
 
 Exchange differences arising on settlements/translations are recognised
 in the Profit and Loss Account. In case of forward exchange contracts
 which are entered into to hedge the foreign currency risk of a
 receivable/payable recognised in these financial statements, premium or
 discount on such contracts are amortised over the life of the contract
 and exchange differences arising thereon in the reporting period are
 recognised in the Profit and Loss Account.
 
 n) Derivative Instruments and Hedge Accounting
 
 The Company has entered into forward contracts and principal and
 interest swap contracts with a bank to hedge its risks associated with
 foreign currency and variable interest rate fluctuations related to
 certain firm commitments and forecasted transactions. These derivative
 contracts are being considered as cash flow hedges applying the
 recognition and measurement principles set out in the Accounting
 Standard 30 Financial Instruments: Recognition and Measurement (AS
 30). The use of hedging instruments is governed by the Company''s
 policies approved by the Board of Directors. The Company does not use
 these contracts for trading or speculative purposes.
 
 To designate a forward contract/swap contract as an effective hedge,
 management objectively evaluates and evidences with appropriate
 supporting documents at the inception of each contract whether the
 contract is effective in offsetting cash flows attributable to the
 hedged risk.
 
 Hedging instruments are initially measured at fair value and are
 re-measured at subsequent reporting dates at fair value. Gain/loss
 arising from year end translation of borrowings drawn down and gain/
 loss arising from changes in fair values of these derivatives that are
 effective hedges are recognized directly in the shareholders'' funds and
 retained there till these hedging instruments either expire or are
 sold, terminated, exercised or no longer qualify for hedge accounting.
 When a hedged transaction is no longer expected to occur, the net
 cumulative gain or loss recognized in shareholders'' funds is
 transferred to the Profit and Loss Account for the year.
 
 In the absence of designation as effective hedge, gain or loss arising
 from changes in fair values of these swap contracts are recognized in
 the Profit and Loss Account.
 
 o) Provisions and Contingent Liabilities
 
 A provision is created when there is a present obligation as a result
 of a past event that probably requires an outflow of resources and a
 reliable estimate can be made of the amount of the obligation. A
 disclosure for a contingent liability is made when there is a possible
 obligation or a present obligation that may, but probably will not,
 require an outflow of resources. When there is a possible obligation or
 a present obligation in respect of which the likelihood of outflow of
 resources is remote, no provision or disclosure is made. Contingent
 assets are neither recognised nor disclosed in the financial
 statements. However, contingent assets are assessed continually and if
 it is virtually certain that an inflow of economic benefits will arise,
 the asset and related income are recognised in the period in which the
 change occurs.
 
 p) Tax
 
 Income tax expense comprises current (i.e. amount of taxes for the year
 determined in accordance with the Income-tax Act, 1961) and deferred
 tax charge or credit (reflecting the tax effects of timing differences
 between accounting income and taxable income for the year). The
 deferred tax charge or credit and the corresponding deferred tax
 liabilities or assets are recognised using the tax rates that have been
 enacted or substantively enacted by the Balance Sheet date.
 
 Deferred tax assets are recognised only to the extent there is
 reasonable certainty that the assets can be realised in future.
 However, where there is unabsorbed depreciation or carried forward loss
 under taxation laws, deferred tax assets are recognised only if there
 is a virtual certainty of realisation of such assets. Deferred tax
 assets are reviewed as at each balance sheet date and written down or
 written up to reflect the amount that is reasonably/virtually certain
 (as the case may be) to be realised.
 
 q) Government Grants
 
 Grants/subsidies are recognised when no uncertainties exist as regards
 receipt of the amount of such grant/subsidy and compliance with the
 attached terms and conditions.
 
 When the grant or subsidy relates to an expense item, it is recognised
 as income over the periods necessary to match them on a systematic
 basis to the costs, which it is intended to compensate.
 Grants/subsidies in respect of fixed assets are adjusted against the
 cost of the related items of fixed assets/capital reserve as the case
 may be.
 
 r) Earnings per Share
 
 Basic earnings per share are computed using the weighted average number
 of equity shares outstanding during the year. Diluted earnings per
 share are computed using the weighted average number of equity and
 dilutive equity equivalent shares outstanding during the year, except
 where the results would be anti dilutive.