NoTimeForCaution

I am a Masters graduate in Engineering (electrical) and I've been working at a hardware company since my graduation about 1.5 years ago. I'm planning to apply for PhD (US & international). I did not do a thesis for my masters - my degree was coursework based. My question is- can I submit LORs for PhD programs in engineering from some of my supervisors/managers/mentors at work? I've interned at work at a couple of companies in highly technical roles. And since I haven't done thesis in my masters, I have better chances of obtaining strong LORs from work than school. I have this question because, from what I know, PhD program is largely academic/research oriented and I'm worried if the LORs I submit through work will even be valued at all. BTW, my supervisors/mentors are PhD holders as well. Thanks!