Dear Mehul
First note that whether wight bridge qualify as goods or not. i think that the equipment you are referring is attached to the ground and you can not move it without dismantling it and in the from of weigh bridge only. i think that after installation it becomes immovable property and does not remain goods. if weight bridge does not qualify as goods suggested category by my learned friend may not be correct.
Secondly you also need to check whether effective control and possession of the goods (if weigh bridge qualify as goods) remain with the service provider or with you. if it is with you, it would amount to deemed sale and a transaction covered under Article 36629-A of the constitution of India. No service tax shall be applicable. yin that case you dont have to worry about appropriate category of serivce at all..
Regards
Akash deep
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