Noise in cold water pipes

Hi.. because you are hearing a tapping sound coming from all cold feed appliances the fault through elimination usually lies with a common supply pipe shared by all appliances/supply points. The first place to start would be where the water enters the house, the stop cock, because this is supplying all points and work forward. The most common cause of noise from experience is usually a non return valve if fitted, this would depend on the age of your property and how recent your pipework was installed, more modern houses will have these installed to comply with water regs but older houses will not. It looks like a long brass straight fitting usually located under the sink in a modern new build type, its common for it to rattle or tap when faulty and does not always affect flow rates when still faulty. The stop tap itself could also cause this if having a seized jumper in the gland but this does usually reduce flow rate, im unsure if your flow rates are affected, you have not stated. Taps can also draw in air if the valves are starting to wear and again can cause rattling /clicking with the valve seats/jumpers moving. A good plumber with reasonable fault finding skills should be able to narrow this down and locate for you.. hope this helps.

It's called water hammer. caused by the pipe work not being clipped or lagged properly or a non-return device fitted. This can happen on any water appliance Taps, Toilets ,Washing machines, and Showers

Sounds like high water pressure from mains supply to the house ,usually you can fit a pressure reducing valve after the house stop cock and this usually solves the tapping rattle pipes especially in older type properties hope this helps.

I agree with all other replies, The water hammer is generally associated with Unclipped loose pipework, Older style taps [not ceramcc disc] where the jumper /the spindle inside the tap to which the washer is fitted is loose fitting, then when water passes through the pipework the jumper moves up and down causing vibration resulting in the noise through the pipework to be experienced. Alternatively, if the property also has a storage tank from which water is drawn off during normal use, it is possible the ball cran in the tank is not closing correctly which can cuuse the float to bounce causing vibration, it is also possible if this is the case an air cushion may be required to resolve on mains inlet to tank.