r passed on 151 CPC is appealable ?

no appeal lies against the order passed US 151 CPC only writ to high court lies

However you can file another aplication U/O 1 rule 10 CPC for the deletion  of the parties

and do not forget to mention the genre in your aplication in which your alleged LR'S are not the necessary aprties like whether they fall in QS, Resi, Or DK and further dont forget to mention that they do not have ant direct and substantive interest in the proceedings and the FD can be executed more effectively only upon their delition from the array/memo of the parties in FD hope this would help

Mr Mohammed Ali, Your petition under section 151 CPC, filed to strike out the names of legal heirs as parties, was dismissed. Though the petition ought to have been filed under Order 1 Rule 10(2) of CPC, it was filed under section 151 CPC.

It is now well established that mere incorrectly quoting or non-mentioning of provision will not be a ground for dismissing the petition. Even, mentioning of section 151 of CPC is enough. 

It is clear from your querry that your petition was dismissed on merits of the case and not for quoting incorrect provision.

For any interloculatory order passed by a lower court, there is a remedy of appeal or revision, provided in the Civil procedure. In your case, certainly there is revision  to High Court available under section 115 of CPC.

No writ petition under article 226 is maintainainable against such order.

Yes Mr. Ramesh stated  is correct.  Only a CRP will lie against this order