Hello and welcome to BL! As stated above, you can mix the two and it will be recreational, although I wouldn't say this combo is entirely "safe," since you can't really expect mixing any downers to be without some element of risk.
The advice I'd like to give you is to start low, and work your way up. Do you have a tolerance to either of these drugs? If not, you should start with 5-10 mg of valium, and 50-100 mg of tramadol to begin with. If you don't feel any drug onset after an hour to an hour and a half, you can work your way up to 10-15 mg valium and 100-200 mg tramadol. Just be very careful with valium, its easy to forget how much you're fucked up while on it, and you can sometimes pop a pill, forget that you popped one, and end up eating another 10 minutes later, and repeating the process til you realize you blacked out and its a day later.
Also you may want to familiarize yourself with the search engine in order to get more information on things you're interested in before starting a new thread! Its on the top bar under "search," and you may want to play around with the search terms in order to get the best results; for example, for this question you could search for "combining tramadol and benzos," or "mixing opiates and benzos" to get an idea of the risks involved in the process.
Good luck and be safe buddy!