Which is a key safety practice when repairing plumbing pipes?

Turning off the water supply is a crucial safety practice when repairing plumbing pipes because it prevents water from flowing through the pipes while maintenance is taking place. This is essential to avoid potential flooding, which can lead to hazardous conditions, damage to property, or injury. By ensuring that the water supply is off, a plumber can work safely and effectively without the risk of sudden water release during the repair process.

Additionally, this practice illustrates good plumbing protocol. It helps maintain a controlled work environment, which is vital for making accurate repairs and preventing unexpected situations that could complicate the job or pose safety risks to the plumber and anyone nearby.