A stupid PVC question

[BigWaz]

If i hook up a check valve and place it before my gate valve will the water pushed back from my gate vavle screw up the check valve?

 

[BigWaz]

i just remembered im not even using pvc on this part, on the upper part i am. im not so i can take it out if i have to
I'm buying this check vavle
http://www.marinedepot.com/md_viewItem.asp?idproduct=FT9144

 

[jbrown11352]

Check valves have been known to fail, I would just drill a small hole in each return about 1/2" below your water line. This wont allow more than 1/2" of water from your display to drain into your sump.

 

[Mike.B]

I dont know that looks like a pretty good check valve, and I think to keep them working good is just unplug your pumps about once a month, let them close and restart the pumps, take 10seconds to make sure there working and to keep them from sticking open.

To drill holes in the lineloc fittings would work but wouldnt the holes get clogged and does anyone have a picture of a hole in the lineloc fittings because I'm going to order 2 checkvalves tommorow but if I could see an example that'd be cool.