Water Pressure:

The cold-water cistern that is fitted in the loft in a house is an example of pressure, as supplies outlets both upstairs and downstairs. The pressure at a downstairs outlet will be higher as the distance is greater to feed, rather than the bathroom sink upstairs, because the distance is shorter and the height is not as steep. This is all relative to the height of the cylinder. Opening the nozzle slightly on a garden hose, a really high jet of pressure can be seen. Now open the nozzle fully and the pressure will be much less, however, the amount of water coming out (its rate of flow) will be bigger. Devices are available on the market that measure this type of pressure and flow. A professional plumber from Swiss Cottage Plumbers will use them. If a new plumbing installation is being planned, the incoming water and flow may be needed to help with the design.


Flow:

The flow rate is normally calculated by the amount of water that can be supplied against a period of time. Lets say for example that a 5ltr bucket takes 5 seconds to fill, the flow rate will be calculated at 1litre per second.


Mains Pressure Gauge:

This gauge gives an accurate pressure reading for a mains supply to a service. It is connected with a standard plumbing thread.


Weir Cup:

This piece of equipment is designed and used to take flow rate readings and will be carried by all plumbing professionals. It reads both litres per second and gallons per minute. Should the rate of flow in a system need reducing the weir cup can be used to measure, then accurately adjust the flow rate to meet the rate required to suit an appliance’s recommended operating specification. A professional installer like a Swiss Cottage Plumber may need to check there is a sufficient flow rate for a condensing boiler.