Water Pressure:
Water pressure can be explained by the example of a cylinder fitted in a loft that contains a large volume of water. The cylinder is the main feed for outlets fitted upstairs and downstairs. If we were to measure the pressure of the water downstairs we would find that it is much higher than that found upstairs. This is due to the bigger distance downhill for the water to run. Naturally the whole pressure question depends on the location and height of the cold-water cylinder.

When you have a garden hose and you open the nozzle slightly, the velocity or jet would definitely be very fast, indicating a high pressure. Now if you if open the nozzle to its maximum, the high pressure jet would fade away somewhat as a greater amount of water flows but the pressure became lower. The flow rate, however would be a lot larger.

There are devices around that can accurately read the flow and the pressure of a system. A professional plumber from Feltham Plumbers will use them. The flow and pressure information is used when planning a future plumbing system installation.

Flow:
This flow rate is usually found by working out the volume of water that can flow compared to the time span. A 3ltr bucket takes 3seconds to fill up, so the rate of flow will be 1litre each second.

Weir Cup:
A weir cup is a piece of kit that is designed to measure the rate of flow by allowing the water to flow through it. It is like a measuring jug but with an outlet at the bottom for the water to pass out. It can read both litres per second and gallons per minute. If the flow rate in a system needs to be reduced, the weir cup is used, and will accurately alter the rate of flow needed to fulfil an appliance’s operating specification. A professional tradesman like a Feltham Plumber understands flow rates.
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