víznyomást

Víznyomás is the pressure exerted by water within a closed piping system. It arises from the weight of the water column and, in pumped systems, from the power of pumps. Víznyomás determines how quickly water flows through pipes and how well fixtures deliver water. In plumbing, two values are often distinguished: static pressure, measured when water is not flowing, and dynamic pressure, measured during flow.

The unit of víznyomás is the pascal (Pa) or the bar, where 1 bar equals 100,000 Pa. Domestic systems commonly operate in the range of about 2–4 bar (roughly 29–58 psi). Higher pressure may be found in some city supplies or near booster stations, while very low pressure can result in weak flow. In tall buildings, pressure tends to decrease with height, and booster pumps or elevated tanks are used to maintain adequate supply on upper floors.

Measurement is performed with pressure gauges installed at the service entry or other test points. Static pressure is read with the system at rest, while dynamic pressure is recorded during steady water use. Pressure management often employs a pressure-reducing valve (PRV) to limit víznyomás within safe levels and to protect pipes and fixtures; typical PRV setpoints are in the range of about 3–4 bar (45–60 psi), depending on local codes and system design.

Excessively high víznyomás can cause leaks, pipe bursts, and increased water losses, while inadequate pressure leads to poor faucet flow and appliance performance. Dynamic pressure fluctuations, known as water hammer, can be mitigated by gradual valve operation, proper pipe sizing, and surge protection measures. In municipal networks, pressure zoning and booster systems help balance supply, efficiency, and reliability.