JUDGMENT : ( 1. ) THE Board of Revenue, M. P. , Gwalior, which is the Tribunal constituted under the M. P. General Sales Tax Act, 1958 (hereinafter referred to as "the Act"), has referred the following question to this Court for its opinion under Section 44 (1) of the Act: Whether in view of the fact that entry 5 in Part I of Schedule II (relating to iron and steel), was amended with effect from 1st April, 1973 by Act No. 35 of 1973, but the entry No. 56 of Part II of Schedule II relating to all types of pipes and pipe fittings, was not amended till 31st August, 1974 when amended so as to exclude pipes covered by entry 5 (xi) of Part I and even this amendment of entry 56 being not given retrospective effect as in the case of entry 12 of Part III, the G. I. pipes and conduit pipes purchased from other registered dealers against payment of full rate of tax without any declaration in form XII are entitled to deduction under Section 2 (r) (ii) or not ? Further, in view of the fact that vide General Circular No. ST/15 (1)/ 73/10722, dated 19th July, 1973 from the office of the Commissioner of Sales Tax, M. P. , Indore, para 8, it was specifically made known that even after 1st April, 1973, G. I. pipes will be taxed 12 per cent as other goods and this circular was amended only on 3rd December, 1973 vide Circular No. VST/l/24 (b)/179/73, dated 3rd December, 1973 and it was told that on reconsideration, it is clarified that G. I. pipes will be treated as declared goods and will be taxed at 3 per cent and previous circular and clarification be treated as cancelled, whether the petitioner is entitled to deduction under Section 2 (r) (ii) of the sale price of G. I. pipes and conduit pipes purchased during the period 1st April, 1973 to 26th October, 1973 from other registered dealers under the doctrine of promissory estoppel-equitable estoppel-new estoppel-a doctrine evolved by equity in order to prevent injustice. ( 2. ( 2. ) BEFORE referring to the facts necessary to answer the aforesaid question, we may point out that Shri H. S. Shrivastava, counsel for the applicant assessee, has made a statement that the dispute which is the subject matter of the aforesaid question, is confined to steel pipes. Viewed in the background of the aforesaid statement, the necessary facts are that the assessee, during" the period between 1st April, 1973 to 26th October, 1973, sold steel pipes which had been purchased by it in turn from the registered dealers, on payment of sales tax. ( 3. ) THE short point on these facts which arises for consideration in the instant case, is as to whether the assessee having already paid sales tax at the stage of purchasing the steel pipes, was liable to pay sales tax again at the stage when it sold the said steel pipes. A perusal of Section 14 of the Central Sales Tax Act, 1956, indicates that it contains a list of declared goods which are of special importance in inter-State trade or commerce. Clause (iv) of Section 14 which deals with iron and steel, was substituted by the Central Sales Tax (Amendment) Act, 1972, with effect from 1st April, 1973. Sub-clause (xi) of Clause (iv) reads : "steel tubes, both welded and seamless, of all diameters and lengths, including tube fittings". ( 4. ) ACCORDING to the finding of the Tribunal, the steel pipes which were purchased by the assessee and subsequently sold by it, fell within entry 5 (xi) of Part I of Schedule II of the M. P. General Sales Tax Act, 1958. The said entry is identical to the entry at Sub-clause (xi) of Clause (iv) of the Central Act. Accordingly, it is apparent that the steel pipes which were sought to be assessed, fell within the category of declared goods under Section 14 of the Central Act with effect from 1st April, 1973. Section 15 (a) of the Central Sales Tax Act, as it stood before 1st July, 1975, i. e. , during the relevant time, read as hereunder: 15. Section 15 (a) of the Central Sales Tax Act, as it stood before 1st July, 1975, i. e. , during the relevant time, read as hereunder: 15. Every sales tax law of a State shall, in so far as it imposes or authorises the imposition of a tax on the sale or purchase of declared goods, be subject to the following restrictions and conditions, namely : (a) the tax payable under that law in respect of any sale or purchase of such goods inside the State shall not exceed three per cent of the sale or purchase price thereof and such tax shall not be levied at more than one stage: ( 5. ) IN view of the facts of the instant case and the provisions contained in Sections 14 and 15 of the Central Sales Tax Act, it is apparent that the assessee having already paid tax on steel pipes when it purchased those pipes from registered dealer, was not liable to pay tax again when the steel pipes were sold by it in its turn in view of the requirement of Section 15 (a) aforesaid that such tax shall not be levied at more than one stage. ( 6. ) IN the result, our answer to the question referred to us is that the assessee-applicant was not liable to pay sales tax in regard to the steel pipes sold by it between the period from 1st April, 1973 to 26th October, 1973 inasmuch as it had already paid tax on the said pipes at the stage when it purchased them from a registered dealer. In the circumstances of the case, however, parties shall bear their own costs.