We are manufacturers of ULM in a country of the European Union, can the type certificate obtained in that country be validated in Spain?

There is no type-certificate validation. To obtain the Spanish type certificate it is necessary to comply with Spanish regulations through a certification process available on the AESA website: https://sede.seguridadaerea.gob.es/sede-aesa/catalogo-de-procedimientos/certificación-de-tipo-ulm