Change of the mesh

Hi all,
is the change of mesh during process needs revalidation of the process or change control only?

Thanks in advance.

This depends upon what is the purpose of sifting (sieving), whether it is for just breaking the loose lumps OR size reduction of the material OR separation of finer particles from coarser particles of the material. Please clarify.

for just breaking the loose lumps

Considering the purpose of sieving as specified by you, this will ba a minor change and does not require any validation. Please confirm that with change of mesh (or new mesh with different mesh size) the purpose is achieved (breaking of loose lumps of material) and if satisfactory, then execute this change through Change control internal SOP.