szelep

A szelep is a mechanical device used to regulate, direct or stop the flow of liquids, gases or slurries within a system. It operates by moving a closing element, such as a disk, ball, cone or wedge, into or away from a seat to control the path and rate of flow. Valves can be operated manually or by automated actuators using electric, pneumatic or hydraulic power. They are fundamental components in a wide range of industries and installations, from simple domestic piping to complex process plants.

Common valve types include ball valves, globe valves, gate valves, butterfly valves, check valves, needle valves and relief or safety valves. Ball valves use a rotating ball for rapid on/off control; globe and gate valves provide throttling and sealing capabilities with linear motion; butterfly valves offer compact rotary control; check valves permit flow in only one direction; needle valves allow fine throttling; relief valves protect equipment by releasing excess pressure. Each type has particular flow characteristics, pressure ratings, and suitable applications.

In automotive and internal combustion engines, the term szelep also refers to engine valves—intake and exhaust valves that regulate air-fuel mixture intake and exhaust gas exhaust. Valve timing and actuation affect engine efficiency, power, and emissions, and valve materials must withstand high temperatures and corrosion.

Construction and installation considerations include material choice, seating surfaces, body and bonnet design, connection type (threaded, flange, weld), and pressure rating (European PN, American Class). Proper maintenance, leakage testing, and correct orientation are essential for reliable operation and safety.