Force from a flow impinging on a flat plate

[kitch]

I need to design a safety device to restrain a flexible hose should a coupling fail. I need to decide on an approximate strength for chain I'm using and so need an estimate of the force from the fluid in the pipe. To calculate this, I would like to model situation as still air at 7 bar in a 5" round pipe impinging on a flat plate at zero distance . I have done some fluid mechanics in the past and feel sure there is a simple equation but cannot find it anywhere (apologies to real fluid engineers who will find this extremely trivial!).

Thanks for your help

 

[GGW]

I guess the best way to define what you need to do is give an example based on your numbers given and some assumed values.

I assume that the 7 bar is gauge pressure. Then the absolute pressure would be 7 barg plus 1 atm or 8.013 bara. I will further assume a temperature of 16 C. From this condition I calculate an air density of 9.696 kg/m3. You state that you have a 5” pipe but a flow is not stated. Again, I will assume a velocity of 25.4 m/s. From this data I will multiply the density x the square of the velocity or 9.696 x (25.4 x 25.4) = 6255 n/m2 is the pressure from the air impinging on a flat plate.

I hope that this will be of some help.