Screw connection
A screw connection is used to connect individual parts, e.g. B. screw and nut .
The term is used especially in sanitary , heating and air conditioning technology for connections of hose or pipelines by two threaded pieces . If a union nut is used here, which presses a flange that is present on one side against the counterpart, then the components to be connected do not have to be twisted against each other themselves.
For pipe connections, screw connections up to a nominal diameter of DN 40 (1 1/2 inches ) and nominal pressures of up to several 100 bar can be used. Compared to a flange connection , a screw connection for small pipe nominal widths is more material-saving and easier to produce, since z. B. No welding work .
In sanitary engineering, pipe fittings are predominantly made of malleable cast iron and gunmetal . Since the new drinking water ordinance, stainless steel screw connections have also been installed more frequently .
In the hydraulics sector in Europe today, cutting ring fittings with nuts and cutting rings are mostly used. Due to the increased use of American and Japanese construction machines , however, screw connections without a "cutting ring" are also gaining ground in which the threaded connections are imperial (BSP or JIC) and have a 60 ° (BSP) or 74 ° (JIC) sealing cone.
For water installations , depending on the pipe material and design, clamping ring or compression fittings as well as Dutch screw fittings are also used.
In the food industry, pipe fittings with "milk pipe threads" according to DIN 11851 are used. These threads are easy-to-clean round threads according to DIN 405.
In refrigeration technology , flanged metal pipes with a blunt cone are screwed together.
In the electrical installation , screw connections are used to introduce strain-relieved and watertight cables into junction boxes, distributors or the like. Until 2004 such screw connections had the PG thread . Nowadays they are made with a metric thread .
See also
Web links
Individual evidence
- ↑ DIN EN 10226: Pipe thread for connections that seal in the thread.
- ↑ DIN EN ISO 228: Pipe thread for connections not sealing in the thread.
- ↑ DIN 11851: Fittings made of stainless steel for foodstuffs and chemicals - screwed pipe connections for rolling in and butt welding.
- ↑ DIN 405: Round threads for general use - thread profiles, nominal dimensions.
- ↑ DIN 40430 (withdrawn): armored thread.
- ↑ DIN EN 60423: Electrical installation pipe systems for electrical energy and for information - outer diameter of electrical installation pipes and threads for electrical installation pipes and their accessories.