Where Does the Delval Surname Come From?
Delval is how some branches of the Duval family came to write their name.
Before spelling was fixed, Duval was also written Delval. Before spelling was standardised, one family could appear under several forms.
A coat of arms belongs to a particular family line rather than to everyone named Delval, so the heraldry linked to Duval is a starting point, not an automatic right. Research your Delval family history with a full surname report and painted coat of arms.