You can get a back water valve. It is similar to a check vale/ the back water valve goes on your main sewer line out side of home. It is desined to stop black water form coming into your home if main line stops up. Thay do make a device that can be installed into an exsisting drain it lets water through your drain but will not let water back up through you shower drain.
Though not a plumber, I can say that shower valves are usually made of brass(a very good material). Therefore they are also expensive to replace (50 dollars for the valve, 150 dollars per shower valve if done by a competent plumber). Therefore, when you notice a leak coming from your shower, try to replace the seat washer (usually the hot water side needs to be replaced first). If you still have a leak, it's time to replace the shower valve.
There is no difference between check valve and NRV, both are same
If you have any water at all coming into the sump, there will always be a little in the bottom unless it stays dry long enough for it to evaporate. The design of the pump doesn't let it pump the last little bit out. If there is not a check valve in the discharge pipe, what is left it the pipe going out will drain back into the sump. If the discharge pipe is connected to the house drain and there was not a check valve in that pipe, depending on where the kitchen clog is, the sink could drain into the sump.
It is the drain for the Temperature and Pressure relief valve (T&P valve, or TPV). It's function is to release pressure from the water heater if the pressure or temperature of the water exceeds preset limits. Do not cap off the pipe, or remove the T&P valve or alter it in any way. Doing so could cause serious injury or death! If you notice water dripping or running from the pipe, call a plumber to check it.
I don't know but I know a site that can help, the forum at Plbg.com
A shower rough-in usually refers to the distance from the wall to the center of the shower drain , measured out away from both walls in a shower to the center of the drain. It also maybe referring to the height and the center line of the placement of the shower valve.
If you mean shower valve, screws are for shower valve coverplate.
It stops by passing of cold into hot and visa vera
Only if the curb stop was manufactured with a drain built in. This type of valve is also known as a "Stop and Waste"
Behind shower valve handle and trim plate
If there is no drain valve at the radiator you can drain the system at the drain valve on the boiler
There should be a drain valve where you can hook up a hose and then open the valve to drain.
Oil check valves are designed to stop the drain-back of oil. A replacement valve costs between $25 and $30 depending on where you buy it.
If the tub has a shower as well, the pipe from the faucet to the shower head could be leaking. You might also check the tube that comes OUT and fills the tub. It could be leaking back at the valve when you turn on the water.
Washing machines should be trapped.
First put a stooper in the drain, then take a 5 gallon pail of water fill the base of the showe let it stand over night and see if anything leaks ( GET THE WATER FROM AOTHER PLACE NOT FROM THE SHOWER) The next day let the water drain this should let you know if it the shower pan /drain pipe. If not leaks then test the grouting by hahing water spashed on it THEN ids still no leak we can explain how to test the shower valve Sylvan Tieger,LMP
Cut out the drywall in the wall behind the shower. Replace the valve. Patch the drywall.