1. The subject three appeals arise out of the common Order-in-Appeal which was passed in respect of three Orders-in-Original Since a common issue is involved in all the three appeals, they were heard together.

2. The facts in brief are that the appellants have a Research & Development Department in their factory. They erected a pilot plant in this department for R & D work. They manufactured about 70% of the components of this pilot plant in their own factory and bought the remaining 307 or so of the components from outside The point to be decided in these three appeals is whether the appellants are liable to pay any Central excise duty on the pilot plant or on the components of the said plant manufactured by themselves In order to facilitate a proper understanding of the issue involved, we reproduce below the relevant exemption notification :- reproduce

"In exercise of the powers conferred by Sub-rule (1) of Rule 8 of the Excise Rules 1944, and in supersession of the notification No. dated 1-3-1975, the Central Govt. hereby exempts goods falling under Item No.68 of First Schedule to the under Item No.68 of the First Schedule to the Central Excises and Salt Act 1944 (1 of 1944)