Well done to all the Practitioners out there risking their health to protect the public over the level four lock down.

Hello,
During the COVID lockdown, I wasn't sure if I can really get a plumber out, but I have a shower in the upstairs bathroom. The hot water cylinder is the other side of the wall, and normally the water pressure was perfectly fine. However, over the last month or so the cold water pressure has dropped significantly. I have no knowledge of plumbing, so hoping for some guidance here for what to check, etc. The sink taps are excellent pressure in the same bathroom, and the hot water is fine and hot, with moderate pressure. I've taken some shots of the HWC and hope someone could suggest some clues. I did notice my water bills have shot up, though I haven't discovered any leaks anywhere.
Please let me know if there's any information I could provide?
Warm Regards, and stay safe

 A factory requires water to be supplied that gives a flow rate of 230 litres per minute at a pressure of 750 kPa at the outlets.
 The supply pressure is 835 kPa.
 Give the minimum diameter of the RPZD that can be installed to meet these requirements.

I know the answer is 64
but is there an equation or formula to find this out

Its troubled times but if we follow the main directive we will survive without confusion.

Hi Plumber

Thank you for that so i assume it is normal then and doesn't pose any danger of blowing the side of my off