No, as I said, the check valve is integral to the pump. If you look, there have been many posts in the past with people having their tank slowly filling up due to the check valve in the pump failing.
Whoops, I didn't read your question right.
Yes, there is a check valve in the city fill fitting. Again, there have been many posts in the past where, when on the pump, water is shooting out of the city fill. If you pull the screen washer out of the city fill you can see this check valve. Many times when water is coming out of the city fill, pushing on the stem of this check valve will fix the problem.
Rick & Debbie; Brandy & Schnoodle Dexter & Fritz R.I.P. the Doxie "Kids"
2015 Jayco Pinnacle 36RSQS 5'er
2013 Chevy Silverado 3500HD LTZ, 6.6L Diesel Dually; B&W Goose Neck and Companion 5'er hitch