Modern Delta showerheads, like all new shower fixtures, are built with a removable water restrictor that limits the flow through the pipe. Federal law requires manufacturers to install restrictors in showerheads that prevent water flow greater than 2.6 gallons per minute; however, the owner of the showerhead may remove the restrictor. The restrictor also reduces water pressure, so if you want to increase shower pressure, remove the device from inside the showerhead. This simple procedure takes less than 10 minutes using basic tools.
Wrap an old cloth around the chrome connector where the Delta showerhead attaches to the wall pipe. The cloth prevents scratching the fixture.
Place the adjustable wrench over the wrapped cloth and tighten. Unscrew the showerhead with the wrench, and remove the fixture from the pipe.
Pull out the washer on the inside of the Delta's threaded coupler using needle-nose pliers.
Grab the opaque nylon cylinder below the washer with needle-nose pliers, and pull it out of the Delta. This part is the water restrictor.
Replace the washer inside the threading on the Delta coupler, and press with your thumb to seat the part in place.
Screw on the Delta to the pipe clockwise by hand. Complete the connection with a quarter-twist using the adjustable wrench.