placed one between the shower pipe and the shower head. Did this because the cold water knob leaks causing shower head to drip. Otherwise, need to cut into wall to replace the cold knob. I did this 10 years before for my home and it works to stop the shower head from dripping because of the leaky water knob. However, I just did it again for a friend and the newly purchased 1/4 turn shut off valve leaks. So, I brought it back to the plumbing store and got a refund. they tell me that law now requires these to drip to stop from scolding ppl. This true?

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