Hi San,
Thank you for contacting Syncfusion support.
Yes, we can print PDF document without saving a file to a disk. We can create a PDF document and save it to a memory stream and print the PDF document from memory stream using PdfViewerControl. After printing the document, we can dispose document stream. We have created a simple sample to achieve your requirement, please find the sample from below link,
Please let us know if you need any further assistance on this.
Regards,
Prakash V