In our glossary, we explain the most important terms that you will frequently encounter in connection with our valve technology.


» Actuating organ
The element necessary to operate the valve, such as a hand lever, gearbox or actuator.

» Actuating time
The switching time from the position "to to open" or "to to close" as a half cycle or "to to close", "to to open" as a full cycle.

» Actuating torque
The torque required to open and close the valve under the existing operating conditions.

 » Actuator
In valve technology, the following actuators are used in addition to manual actuation (manual operation):
- electric actuators
- pneumatic actuators
- hydraulic actuators
Selection criteria are the required force or torque and/or the degree of automation of the application [→ More Info]

» Antistatic design
A valve with anti-static design provides electrical conductivity between all parts in contact with the medium and the pressure-bearing body.

» Ball valve
Valve with a ball as the closing body, which rotates about an axis perpendicular to the direction of flow and through which flow passes in the open position. [→ More Info]

» Body
Connecting piece between two pipelines, which is connected by means of bolts. As a rule, a flange is an annular washer, which is attached to the end of a pipe.

» Bursting disc
A non-reclosing relief device for protection against overpressure. It includes the complete unit of installed components (e.g. bursting disc holder, vacuum support, etc.). [→ More Info]

» Butterfly valve
Shut-off valves with a closing body (valve disc) which rotates about an axis perpendicular to the direction of flow and around which the flow passes in the open position. [→ More Info]

» Cavitation
Formation and abrupt collapse of bubbles filled with steam when the pressure drops below the steam pressure of the of the medium.

» CE mark
The CE mark is an indication that products have been tested for all EU-wide safety, health and environmental requirements.

» Check valve
→ see non-return valve

CIP stands for "clean-in-place" and refers to plant cleaning in which valves do not have to be removed from the piping system. This is done via separate rinsing connections on the valve. CIP systems are frequently used in the food, beverage and pharmaceutical industries.

» Coating
A coating to protect against corrosion and/or contamination, applied to a component of a valve or an entire valve.

» Control pressure
The fluid pressure required to supply pneumatic or hydraulic actuators.

» Cryo valve
Cryogenic valves are used in cryogenic technology. These valves can be used at a medium temperature of up to -200 degrees. [→ Cryo Ball Valve], [→ Cryo Butterfly Valve]

» Differential pressure
Pressure difference between two given spatial points. Mostly in front of and behind a valve.

» Differential pressure sensor
Measure the pressure difference between two given spatial points.

» Double acting actuator
Valve actuator which is dependent on an external energy source (often compressed air) in both switching directions (open and closed). [→ More Info]

» Double membran pump
A working machine that transfers mechanical work to a fluid, pumping it to a higher level and/or increasing the pressure. [→ More Info]

» External spindle thread
Actuating element on manually and electrically operated knife gate valves, outside the pressure chamber.

» Face-to-face dimension
Distance between the end faces of the valve, specified in millimeters. Standardized according to DIN EN 558 or also API 609.

» Fail-Safe position
The switching direction (open or closed) that is permanently achieved with a single-acting actuator without auxiliary energy (compressed air and/or current).

» Flange
Connecting piece between two pipelines, which is connected by means of bolts. As a rule, a flange is an annular washer, which is attached to the end of a pipe.

» Hand lever
A hand lever is used to open and close shut-off valves with human muscle power using a lever.

» Handwheel
A handwheel is used to open and close shut-off valves with human muscle power by wheel.

» High performance valve
Butterfly valve based on the double eccentric or triple eccentric principle. [→ More Info]

» Hose valve
Or hose pinch valves usually consist of a tubular, round through-hole housing and an elastomer hose section inserted therein as a sleeve, which is sealed at both ends by a flange to the housing. If the hose is squeezed (mechanically or by means of fluid), the free passage closes. [→ More Info]

» Kv value
Also flow factor. Water flow through a valve (in m³/h) at a pressure difference of 1 bar and a water temperature of 5 °C - 30 °C.

» Leakage
Also leakage rate. Unwanted leakage of medium to the outside or in the closure of a valve. Often caused by defective seals. Permissible leakages in the closure are regulated according to EN 12266-1.

» Lug type body
Valve body with through holes or with thread for screwing on the adjacent pipe flanges.

» Nominal pressure PN
Parameter for reference purposes for components of piping systems. Specified as pressure in bar. There are different PN levels. PN2.5 PN6, PN10, PN16, PN25, PN40 and higher.

 » Non-return valve
Valve as a backflow preventer with a flap plate as a closing element. [→ More Info]

» Norminal size DN
Nominal size, abbreviated DN, refers to the inside diameter of a pipe or the size of the connection dimension of the shut-off valve.

» Packing
Component made of flexible sealing materials for sealing the moving actuating element (often the switching shaft) through the pressure-bearing housing.

» Packing space
Space in the valve body to accommodate the packing.

Polyetheretherketone (abbreviated to PEEK) is a high-temperature-resistant thermoplastic and belongs to the polyaryletherketone group of substances. The melting temperature is 335 °C.

» Pressure Equipment Directive (PED)
A European Directive of the European Parliament (2014/68/EU) harmonizing the laws of the Member States. It defines the requirements for making pressure equipment available and placing it on the market within the European Economic Area.

» Pressure loss
Pressure difference caused by friction in the pipeline or also by pipe bends and valves.

» Pressure surge
A pressure surge (also water hammer) refers to the dynamic change in pressure of a fluid in a pipeline that occurs when a shutoff valve closes too quickly. [→ More Info]

Polytetrafluoroethylene (PTFE) is a polymer made of fluorine and carbon. Colloquially, this plastic is often referred to by the trade name Teflon from the company DuPont. Best chemical properties. Often used as a sealing material in valves.

 » Sealing
In valve technology, a distinction is made between two types of tightness:
- external tightness, i.e.: atmosphere
- internal tightness, i.e.: tightness against the flow of a medium in the direction of flow

» Seat ring
Sealing element on the closing body.

» Shut-off valve
Are used to close and open material flows in pipelines.

The safety integrity level (SIL) is used to assess electrical systems in terms of the reliability of safety functions.

» Single acting actuator
Valve actuator which is dependent on an external energy source (often compressed air) only in one switching direction (open or closed). The other direction is switched by mechanical force (often springs). [→ More Info]

» Starting torque
 Is the torque transmitted during the starting process of the actuator.

» Steam control valve
High performance valve for steam control. A metallic seal ensures that the loads occurring during the control process do not damage the valve.

» Top Entry
Valves where the internal parts can be replaced from the top. This housing opening is screwed pressure-tight.

» Torque
The force required as the moment necessary to open, close, or actuate a valve.

» Type of construction
Valve type (e.g. ball valve, butterfly valve, valve) regulated by EN 736 part 1-3.

» Valve
Valve in which the closing body movement is straight and parallel to the direction of flow in the direction of the seat surface.

» Valve test bench
System to test a valve for function and tightness after completion.