D
100 Posts in this encyclopedia categoryD Nozzle (Small Fire Nozzle)
The D nozzle is a small, handy nozzle used together with the D hose. It is especially suited for incidents requiring small amounts of water and precise water application, such as fighting incipient fires or vegetative fires. The D nozzle enables targeted and controlled water delivery, making it an essential tool in specialized firefighting scenarios.
D-hose
The D-hose is a very small and flexible firefighting hose primarily used for special applications such as tackling incipient fires or combating wildland and vegetation fires. With a diameter of 25 mm (D25), it is the smallest standardized pressure hose used by fire services. Its compact size and easy handling make the D-hose ideal for operations where large volumes of water are not required.
Dam failure
A dam failure refers to the sudden collapse or destruction of a dam, releasing large volumes of water uncontrollably. Such an event can lead to catastrophic flooding and cause severe damage to infrastructure, the environment, and human life. Dams are typically built to store or control water, and their failure poses a significant threat.
Danger Zone
A danger zone (DZ) is an area classified by the police or other security authorities as high-risk. Special security measures are taken in such zones to ensure public safety. The abbreviation DZ is often used for danger zone.
Deep drawing
Deep drawing is a forming process in which flat sheet metal blanks are drawn into a hollow mold to create complex three-dimensional shapes. This process is widely used in the automotive, packaging, household appliance, and aerospace industries. Deep drawing enables the production of precise and complex components in large quantities.
Deep Groove Ball Bearings
Deep groove ball bearings are a widely used type of rolling bearings employed in numerous applications. They are characterised by their ability to accommodate both radial and axial loads, making them a versatile solution for many machines and devices.
deflagration
A deflagration is a sudden, often weak explosion caused by the rapid combustion of a flammable mixture. This process can occur when flammable gases or vapors accumulate in a confined space and are then ignited by an ignition source such as a spark or flame. Deflagrations are less violent than explosions but can still cause significant damage and pose a hazard in many industrial and domestic environments.
deformation
Deformation refers to the change in the shape or size of a body due to external influences such as forces, pressure, or temperature. This process can be elastic, in which the material returns to its original shape after the load is removed, or plastic, in which the deformation is permanent. Deformation occurs in a wide variety of materials, including metals, plastics, rubber, and even the Earth's crust.
Dekon-F
Dekon-F stands for "Decontamination Vehicle" and refers to a specialized fire department vehicle used for decontaminating people, emergency personnel, and equipment during operations involving hazardous substances. The Dekon vehicle is equipped with the necessary tools to carry out rapid and effective on-site decontamination, preventing the spread of dangerous materials and ensuring the safety of responders and the public.
Dekon-Fl
Dekon-Fl stands for "Decontamination of Surfaces" and refers to a specialized system or vehicle used by fire departments to decontaminate large surface areas. These systems are deployed during incidents involving chemical, biological, radiological, or nuclear (CBRN) hazards to clean contaminated zones and prevent the spread of dangerous substances.
Dekon-G
Dekon‑G stands for "Decontamination Unit" and refers to specialized fire brigade vehicles or trailers used to decontaminate operational tools, protective gear, and similar equipment. These units are designed to thoroughly clean gear after deployments involving chemical, biological, radiological, or nuclear (CBRN) hazards, removing hazardous residues.
Dekon-V
Dekon-V stands for "decontamination of injured persons" and refers to specialized fire service units deployed to decontaminate injured individuals after exposure to hazardous substances. These units are designed to quickly and effectively decontaminate injured persons on site to prevent the spread of dangerous substances and ensure the safety of those affected before they are transferred for further medical treatment.
Dekon‑P
Dekon‑P stands for "personnel decontamination" and refers to specialized fire service units deployed to decontaminate individuals after exposure to hazardous substances. These units are designed to perform rapid and effective on-site decontamination, helping to prevent the spread of contaminants and ensuring the safety and health of affected individuals.
Delay
Warpage describes the undesirable change in the shape of a material or component caused by internal stresses, thermal influences, or mechanical loads. This process causes the component to deviate from its originally designed geometry, which can lead to inaccurate fit, loss of function, and, in some cases, structural failure. Warpage occurs in many industries, particularly in mechanical engineering, metalworking, and construction.
Delta sander
Delta sanders are compact power tools specifically designed for sanding corners, edges, and hard-to-reach areas. Thanks to their triangular sanding pad, they are ideal for precise sanding tasks and are commonly used in renovation, furniture making, and woodworking.
Dental burr file
A tooth file, also called a gear file or tooth file, is a specialized tool used for working on and deburring gears and fine metal surfaces. These files are indispensable in precision engineering, mechanical engineering, and watchmaking, as they allow for precise and controlled material removal.
Depósitos de cal
Los depósitos de cal, también conocidos como sarro o piedra caliza, se forman por la precipitación de carbonato de calcio y magnesio presentes en el agua dura. Estas incrustaciones pueden aparecer en electrodomésticos, tuberías, sistemas de calefacción y superficies que están en contacto frecuente con el agua. Los depósitos de cal no solo reducen la eficiencia de los aparatos, sino que también pueden acortar su vida útil y ocasionar costosas reparaciones.
Detonation
A detonation is a form of rapid combustion in which the flame front propagates through an explosive mixture at supersonic speed. This extremely fast and intense chemical reaction creates a shockwave that spreads rapidly and has a high destructive potential. Detonations are typical of explosive events, such as those involving explosives or, in some cases, fires.
Diamond tools
Diamond tools are specialized instruments that use diamonds as cutting or grinding agents. Due to the hardness of diamonds, these tools are excellent for processing hard materials like concrete, stone, glass, and ceramics. They offer high precision and durability, making them indispensable in many industrial and craft applications.
Diffusion-tight
The term "diffusion‑tight" refers to materials or coatings that nearly completely prevent the passage of gases and moisture. Such materials are indispensable in many applications—construction, packaging, and electronics—because they protect sensitive components and structures from the harmful effects of moisture and gas infiltration.
Digital personal alert receivers
Digital personal alert receivers (DME) are small, portable devices used by firefighters and other emergency personnel to receive alarms and operational information digitally. They are an essential tool in firefighting to ensure that personnel are informed about emergencies quickly and reliably.
DIN 11024
DIN 11024 is a standard from the German Institute for Standardization (DIN) for cotter pins, also known as safety pins or hairpin cotters. This standard defines the dimensions, tolerances, and mechanical properties of cotter pins used to secure bolts and studs in various mechanical and structural applications. Cotter pins according to DIN 11024 are available in various sizes and materials to meet different requirements.
DIN 125
DIN 125 is a standard from the German Institute for Standardization (DIN) for flat washers. This standard defines the dimensions, materials, and technical requirements for flat washers used in a wide range of mechanical and structural applications. Washers according to DIN 125 are available in various sizes and materials to meet different requirements.
DIN 127
DIN 127 is a standard from the German Institute for Standardization (DIN) for spring washers. This standard defines the dimensions, tolerances, and mechanical properties of spring washers used to secure bolted connections. Spring washers according to DIN 127 are available in various sizes and materials to meet different requirements.
DIN 13155
DIN 13155 is a standard from the German Institute for Standardization (DIN) for first aid kits. This standard specifies the requirements for the contents and condition of first aid kits that must be provided in various work environments and public facilities. First aid kits according to DIN 13155 are designed to ensure fast and effective initial treatment for injuries and accidents.
DIN 137
DIN 137 is a standard from the German Institute for Standardization (DIN) for spring washers, also known as locking washers. This standard defines the dimensions, tolerances, and mechanical properties of spring washers used to secure bolted connections. Spring washers according to DIN 137 are available in various sizes and materials to meet different requirements.
DIN 14640
DIN 14640 is a standard that specifies requirements and specifications for the mounting of spotlights in firefighting applications. It defines the dimensions and properties of the mounting bore, mounting pin, and joint piece. This standard ensures uniform and safe attachment of spotlights to firefighting vehicles and equipment, which is crucial for optimal function and safety during operations.
DIN 14800
DIN 14800 is a standard from the German Institute for Standardization (DIN) for firefighting equipment, specifically for hose reels and their accessories. This standard defines the dimensions, tolerances, and mechanical properties of reels used in fire trucks and fixed installations to store fire hoses and other equipment neatly and ready for use. Reels according to DIN 14800 are available in various designs to meet different requirements.
DIN 1481
DIN 1481 is a standard by the German Institute for Standardization (DIN) for slotted spring pins, also known as spring tension pins or roll pins. This standard defines the dimensions, tolerances, and mechanical properties of spring pins used for securing and positioning components in various mechanical and structural applications. DIN 1481 pins are available in different sizes and materials to meet a wide range of requirements.
DIN 14922
DIN 14922 specifies requirements for multipurpose bags used by firefighters. These bags are designed for the safe transport of fire service ropes or operational tools. The standard ensures the bag does not restrict the wearer’s freedom of movement or diminish the protective function of their personal protective equipment (PPE).
DIN 1587
DIN 1587 is a standard from the German Institute for Standardization (DIN) for cap nuts (also known as dome nuts). This standard defines the dimensions, tolerances, and mechanical properties of cap nuts, used in a wide range of mechanical and structural applications. DIN 1587 cap nuts are available in various sizes and materials to meet different requirements.
DIN 471
DIN 471 is a standard from the German Institute for Standardization (DIN) for retaining rings for shafts (circlips). This standard defines the dimensions, tolerances, and mechanical properties of retaining rings that are mounted on shafts to prevent axial movement of components. DIN 471 retaining rings are available in various sizes and materials to meet diverse requirements.
DIN 472
DIN 472 is a standard from the German Institute for Standardization (DIN) for retaining rings for bores (also known as internal circlips). This standard defines the dimensions, tolerances, and mechanical properties of retaining rings inserted into bores to prevent axial movement of components. DIN 472 retaining rings are available in various sizes and materials to meet different requirements.
DIN 571
DIN 571 is a standard from the German Institute for Standardization (DIN) for hex-head wood screws, also known as lag screws or timber construction screws. It defines the dimensions, tolerances, and mechanical properties of wood screws used in various wood connections. Hex-head wood screws according to DIN 571 are available in various sizes and materials to meet different requirements.
DIN 603
DIN 603 is a standard from the German Institute for Standardization (DIN) for flat round-head bolts with square neck. It defines the dimensions, tolerances, and mechanical properties of round-head bolts used in various mechanical and structural applications. Flat round-head bolts according to DIN 603 are available in a range of sizes and materials to meet different requirements.
DIN 6798
DIN 6798 is a standard from the German Institute for Standardization (DIN) for serrated lock washers. It defines the dimensions, tolerances, and mechanical properties of lock washers used to secure bolted connections. Washers per DIN 6798 are available in various sizes and materials to meet different requirements.
DIN 7985
DIN 7985 is a standard of the German Institute for Standardization (DIN) for cylindrical screws with a cross recess. This standard defines the dimensions, tolerances, and mechanical properties of cylindrical screws used for general fastening purposes in various industrial and commercial applications. Cylindrical screws according to DIN 7985 are available in different sizes and materials to meet diverse requirements.
DIN 9021
DIN 9021 is a standard from the German Institute for Standardization (DIN) for large washers. This standard defines the dimensions, tolerances, and mechanical properties of washers used to increase the bearing surface area of bolts and nuts. Washers according to DIN 9021 are available in various sizes and materials to meet different requirements.
DIN 912
DIN 912 is a standard from the German Institute for Standardization (DIN) for cylindrical screws with an internal hexagon socket. This standard defines the dimensions, tolerances, and mechanical properties of cylindrical screws used for a wide range of mechanical and structural applications. Cylindrical screws according to DIN 912 are available in various sizes and materials to meet different requirements.
DIN 913
DIN 913 is a standard from the German Institute for Standardization (DIN) for threaded pins with internal hexagon and conical tip. This standard defines the dimensions, tolerances, and mechanical properties of threaded pins used to secure components in bores or on shafts. Threaded pins according to DIN 913 are available in various sizes and materials to meet different requirements.
DIN 914
DIN 914 is a standard from the German Institute for Standardization (DIN) for threaded pins with internal hexagon and point. This standard defines the dimensions, tolerances, and mechanical properties of threaded pins used to secure components in bores or on shafts. Threaded pins according to DIN 914 are available in various sizes and materials to meet different requirements.
DIN 915
DIN 915 is a standard from the German Institute for Standardization (DIN) for threaded pins with internal hexagon and shoulder. This standard defines the dimensions, tolerances, and mechanical properties of threaded pins used to secure components in bores or on shafts. Threaded pins according to DIN 915 are available in various sizes and materials to meet different requirements.
DIN 931
DIN 931 is a standard from the German Institute for Standardization (DIN) for hexagon bolts with a shank and partial thread. This standard defines the dimensions, tolerances, and mechanical properties of hexagon bolts used in a wide range of mechanical and structural applications. Hexagon bolts according to DIN 931 are available in various sizes and materials to meet different requirements.
DIN 933
DIN 933 is a standard from the German Institute for Standardization (DIN) for hexagon bolts with full thread. This standard defines the dimensions, tolerances, and mechanical properties of hexagon bolts used for general fastening purposes in various industrial and commercial applications. Hexagon bolts according to DIN 933 are available in various sizes and materials to meet different requirements.
DIN 934
DIN 934 is a standard from the German Institute for Standardization (DIN) for hexagon nuts. This standard defines the dimensions, tolerances, and mechanical properties of hexagon nuts used in a wide range of mechanical and structural applications. Hexagon nuts according to DIN 934 are available in various sizes and materials to meet different requirements.
DIN 94
DIN 94 is a standard by the German Institute for Standardization (DIN) for split pins, also known as cotter pins. This standard defines the dimensions, tolerances, and mechanical properties of split pins used for securing nuts and bolts in various mechanical and structural applications. Split pins according to DIN 94 are available in different sizes and materials to meet varying requirements.
DIN 965
DIN 965 is a standard from the German Institute for Standardization (DIN) for countersunk screws with a cross recess. This standard defines the dimensions, tolerances, and mechanical properties of countersunk screws featuring a 90° countersunk head and a Phillips cross-drive. Countersunk screws according to DIN 965 are available in various sizes and materials to suit different requirements.
DIN 966
DIN 966 is a standard from the German Institute for Standardization (DIN) for countersunk lens-head screws with a cross recess. This standard defines the dimensions, tolerances, and mechanical properties of screws with a 90° countersunk lens head and a Phillips cross-drive. Screws according to DIN 966 are available in various sizes and materials to meet different requirements.
DIN 985
DIN 985 is a standard from the German Institute for Standardization (DIN) for self-locking hexagon nuts with a polyamide locking insert (also known as Nyloc nuts). This standard defines the dimensions, tolerances, and mechanical properties of these nuts, which are used in various mechanical and structural applications to prevent fastener loosening due to vibration.
DIN EN IEC standards
DIN EN IEC standards are international standards developed by the German Institute for Standardization (DIN) in cooperation with the European Committee for Standardization (CEN) and the International Electrotechnical Commission (IEC). These standards aim to promote uniform technical standards for electrical and electronic products worldwide.
DIN EN ISO Standard
DIN EN ISO standards are international standards developed by the German Institute for Standardization (DIN) in cooperation with the European Committee for Standardization (CEN) and the International Organization for Standardization (ISO). These standards aim to promote uniform technical standards worldwide by combining European and international requirements.
DIN EN ISP Standards
DIN EN ISP standards are international standards developed by the German Institute for Standardization (DIN) in cooperation with the European Committee for Standardization (CEN) and the International Organization for Standardization (ISO). These standards aim to promote uniform technical standards across various industrial sectors worldwide.
DIN EN Standard
The DIN EN Standard is a European standard developed by the German Institute for Standardization (DIN) in cooperation with European standardization organizations such as CEN (European Committee for Standardization) and CENELEC (European Committee for Electrotechnical Standardization). These standards are uniform across all member countries of the European Union and the European Economic Area.
DIN ETS Standard
DIN ETS standards are European telecommunications standards developed by the German Institute for Standardization (DIN) in cooperation with the European Telecommunications Standards Institute (ETSI). These standards aim to promote uniform technical standards for telecommunications products and services across Europe.
DIN VDE Standard
DIN VDE standards are technical standards developed by the German Institute for Standardization (DIN) in collaboration with the Association for Electrical, Electronic & Information Technologies (VDE). These standards aim to ensure the safety, reliability, and efficiency of electrical and electronic products as well as installations.
Direct Mode Operation
The term Direct Mode Operation (DMO) refers to an operating mode in the digital radio network of public safety and emergency services (BOS). In DMO mode, radios can communicate directly with each other without going through a base station or fixed network. This is especially useful in situations where there is no network coverage or communication must be independent of the network.
Disaster Protection
Disaster protection (KatS) includes all measures taken to protect people, animals, property, and the environment from the effects of disasters or to manage their consequences. In Germany, disaster protection is a joint responsibility involving various organizations, including fire departments, the Federal Agency for Technical Relief (THW), rescue services, and aid organizations. Disaster protection is both preventive and reactive.
discoloration
Discoloration describes the change in the original color of a material, surface, or product. This process can be caused by various factors such as UV radiation, chemical reactions, aging, moisture, or mechanical influences. Discoloration occurs in many areas, including textiles, plastics, wood, metals, and even on skin. It can cause both aesthetic and functional problems.
Double Anchor Hitch
The double anchor hitch is an important knot in firefighting, mainly used to secure ropes to fixed objects. It is especially reliable and offers high safety because it does not slip under load and is easy to untie. The double anchor hitch is often used in rescue operations, securing equipment, or working at heights.
Double Nipple
A double nipple, also known as a pipe double nipple or simply nipple, is a short pipe section with external threads on both ends used to connect two pipes or fittings. These connectors are indispensable in plumbing, heating and air conditioning technology, as well as in industrial piping, as they allow for a simple and secure connection.
Double-Ended Wrench
A double-ended wrench, also called a double open-end wrench, is a handy and versatile tool indispensable in many workshops and households. It is a spanner with two different jaw sizes at each end, allowing for flexible and practical use.
Draft seal
A draught excluder, also called a door seal or window seal, is an important component for sealing doors and windows to prevent the ingress of drafts, dust, noise, and moisture. It contributes to improving a building's energy efficiency by minimizing heat loss and thus reducing heating costs.
drain blockage
A drain blockage is a common problem in households and can occur in kitchens, bathrooms or toilets. It happens when materials such as hair, soap residues, food scraps or grease accumulate in the drain pipes and obstruct the water flow. This leads to slow drainage, unpleasant odors and, in the worst case, backups that can cause significant damage.
Drawknife
A drawknife, also called a spokeshave or scraper, is a hand tool used primarily in woodworking. It is used to scrape, peel, and smooth wood to achieve a clean and precise surface. Drawknives are especially indispensable in the manufacture of furniture, wood sculptures, and barrel staves.
Drill Bit Breakage
Drill bit breakage refers to the fracturing of a drill bit during the drilling process. This can be caused by excessive force, incorrect handling or material fatigue. Drill bit breakage is not only inconvenient but can also result in injuries and damage to workpieces.
Drilling
Drilling is a machining process in which a rotating tool, the drill bit, is used to create cylindrical holes in various materials such as metal, wood, plastic or concrete. This method is widely used in the manufacturing industry and plays a central role in the production and processing of components.
Drone
Drones, also known as unmanned aerial vehicles (UAVs), are aircraft operated without a pilot onboard. They are controlled via remote control or autonomously through preset flight plans and advanced algorithms. Drones have a wide range of applications—from military and commercial to private use. Their ability to operate in hard-to-reach areas makes them indispensable across many fields.
dust explosion
A dust explosion is an explosive reaction that occurs when combustible dust particles are suspended in the air and ignite. This type of explosion can be extremely destructive and often occurs in industrial environments where large quantities of fine dust particles, such as flour, wood dust, coal dust, or metal dust, are present. Dust explosions pose a significant threat to the safety of people and equipment.
Duty Gloves
Duty gloves are specialized gloves designed for use by police, firefighters, military personnel, and other emergency and security services. They provide protection against various hazards such as cuts, punctures, heat, and chemicals, while maintaining high dexterity and flexibility. These gloves are an essential part of personal protective equipment (PPE) for first responders.
DVGW Approval
The DVGW approval, issued by the German Association for Gas and Water (DVGW), is a certification that attests compliance with high quality and safety standards for products and services in the gas and water installation sector. This approval is an important indicator of safety, reliability, and performance for installation components and systems.