This article contains translated text and the factual accuracy of the translation should be checked by someone fluent in Russian and English. (February 2024)
The civilian GP-4u gas mask consists of the facepiece, the hose and a cylinder-shaped filter, which is screwed onto the end of the hose. As the wearer breathes in air, the filter removes certain poisonous materials including toxins and microorganisms.
The facepiece of the mask consists of rubber that comes in three colors: black, white and green, the green being the most common color found on GP-4u gas masks, as well as two round glass lenses attached to the face-piece via metal. On the bottom side of the gas mask is the inhale-valve (on the front) which is where the hose starts, and an exhale valve behind it. The facepiece filters air and protects the wearer's lungs, eyes, and facial features from external contaminants.
The hose is permanently attached to the inhale valve at one end and connects to the filter at the other. Its sole function is to safely transport filtered air to the inhale valve for inhalation.
The filters made for the GP-4u are known to contain asbestos and are long expired and outdated. They are not recommended for use by anybody.
Design
The gas mask filter is used for purifying the inhaled air from poisonous and radioactive substances, as well as pathogenic microbes and toxins. The "coffee-can" style filter has a GOST thread for attaching the filter to the inhale valve of the gas mask.
The face piece of the gas mask consists of a latex hood with a goggle assembly, a valve housing and a filter hose.
It has three sizes: 1, and 3 The valve house serves to distribute the flow of inhaled air and dispose of the exhaled air. In the lower part of the valve chamber there is a removable screen with holes, designed to protect the valve from mechanical damage during use and from falling out. The connected hose is used to connect the gas mask to the filter.
The upper end of the hose is tightly fixed on the branch pipe of the valve housing. The connecting hose is made of rubber covered with knitted fabric and has transverse corrugations, which give it necessary elasticity and flexibility when bending. The mask is applied to the head with a back piece and strapping system consisting of two non-stretchable frontal, four temporal and two occipital rubber straps ensuring an airtight fit to the face. The tension of the straps is adjusted by the movable buckles on the frontal straps and the fixed buckles on the occipital straps. The mask's bag is used to store and carry the mask and its accompanying equipment. In the case of a chemical weapon attack the bag can act as a prefilter to remove particles of radioactive dust from the air entering the mask. The bag has two compartments: one for the filter, and one for the mask and wax paper cutouts used to protect the glasses from permanently fogging over in storage. At the bottom of the bag, in the compartment for the filter, there are two wooden slats that facilitate air access to the gas mask box. The bag closes with a flap and fastens with a button or strap. To carry the gas mask over the shoulder, a shoulder strap with a movable buckle is sewn onto the bag. A cloth band or cord and a metal half-ring or cloth eyelet are sewn onto the ribs of the bag facing the torso when carrying the gas mask, designed to secure the bag to the torso when carrying the gas mask in the "ready" and "ready-to-wear" positions.
Equipment
The set of civil gas mask GP-4U includes:
Front part - 1 piece
Filtering and absorbing box - 1 piece
Gas mask bag - 1 piece
An anti-fogging agent for glasses of the spectacle assembly ("pencil") - 1 piece
Instructions for use - 1 piece per packing place
Certificate of standard quality - 1 piece per batch
In the mid-50s of the 20th century, the GP-4U was discontinued in favour of the modern, easier and cheaper to produce GP-5, although the production of GP-4U continued until 1974.
Sources
Инструкция по использованию противогаза ГП-4у. Москва, 1956.
A gas mask is a piece of personal protective equipment used to protect the wearer from inhaling airborne pollutants and toxic gases. The mask forms a sealed cover over the nose and mouth, but may also cover the eyes and other vulnerable soft tissues of the face. Most gas masks are also respirators, though the word gas mask is often used to refer to military equipment, the scope used in this article. Gas masks only protect the user from ingesting or inhaling chemical agents, as well as preventing contact with the user's eyes. Most combined gas mask filters will last around 8 hours in a biological or chemical situation. Filters against specific chemical agents can last up to 20 hours.
A scuba set, originally just scuba, is any breathing apparatus that is entirely carried by an underwater diver and provides the diver with breathing gas at the ambient pressure. Scuba is an anacronym for self-contained underwater breathing apparatus. Although strictly speaking the scuba set is only the diving equipment that is required for providing breathing gas to the diver, general usage includes the harness or rigging by which it is carried and those accessories which are integral parts of the harness and breathing apparatus assembly, such as a jacket or wing style buoyancy compensator and instruments mounted in a combined housing with the pressure gauge. In the looser sense, scuba set has been used to refer to all the diving equipment used by the scuba diver, though this would more commonly and accurately be termed scuba equipment or scuba gear. Scuba is overwhelmingly the most common underwater breathing system used by recreational divers and is also used in professional diving when it provides advantages, usually of mobility and range, over surface-supplied diving systems and is allowed by the relevant legislation and code of practice.
A self-contained breathing apparatus (SCBA) is a respirator worn to provide an autonomous supply of breathable gas in an atmosphere that is immediately dangerous to life or health from a gas cylinder. They are typically used in firefighting and industry. The term self-contained means that the SCBA is not dependent on a remote supply of breathing gas. They are sometimes called industrial breathing sets. Some types are also referred to as a compressed air breathing apparatus (CABA) or simply breathing apparatus (BA). Unofficial names include air pack, air tank, oxygen cylinder or simply pack, terms used mostly in firefighting. If designed for use under water, it is also known as a scuba set.
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the user. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, while also eliminating the bubbles otherwise produced by an open circuit system. The latter advantage over other systems is useful for covert military operations by frogmen, as well as for undisturbed observation of underwater wildlife. A rebreather is generally understood to be a portable apparatus carried by the user. The same technology on a vehicle or non-mobile installation is more likely to be referred to as a life-support system.
A diving regulator or underwater diving regulator is a pressure regulator that controls the pressure of breathing gas for underwater diving. The most commonly recognised application is to reduce pressurized breathing gas to ambient pressure and deliver it to the diver, but there are also other types of gas pressure regulator used for diving applications. The gas may be air or one of a variety of specially blended breathing gases. The gas may be supplied from a scuba cylinder carried by the diver, in which case it is called a scuba regulator, or via a hose from a compressor or high-pressure storage cylinders at the surface in surface-supplied diving. A gas pressure regulator has one or more valves in series which reduce pressure from the source, and use the downstream pressure as feedback to control the delivered pressure, or the upstream pressure as feedback to prevent excessive flow rates, lowering the pressure at each stage.
A full-face diving mask is a type of diving mask that seals the whole of the diver's face from the water and contains a mouthpiece, demand valve or constant flow gas supply that provides the diver with breathing gas. The full face mask has several functions: it lets the diver see clearly underwater, it provides the diver's face with some protection from cold and polluted water and from stings, such as from jellyfish or coral. It increases breathing security and provides a space for equipment that lets the diver communicate with the surface support team.
A respirator is a device designed to protect the wearer from inhaling hazardous atmospheres including lead fumes, vapors, gases and particulate matter such as dusts and airborne pathogens such as viruses. There are two main categories of respirators: the air-purifying respirator, in which respirable air is obtained by filtering a contaminated atmosphere, and the air-supplied respirator, in which an alternate supply of breathable air is delivered. Within each category, different techniques are employed to reduce or eliminate noxious airborne contaminants.
A breathing apparatus or breathing set is equipment which allows a person to breathe in a hostile environment where breathing would otherwise be impossible, difficult, harmful, or hazardous, or assists a person to breathe. A respirator, medical ventilator, or resuscitator may also be considered to be breathing apparatus. Equipment that supplies or recycles breathing gas other than ambient air in a space used by several people is usually referred to as being part of a life-support system, and a life-support system for one person may include breathing apparatus, when the breathing gas is specifically supplied to the user rather than to the enclosure in which the user is the occupant.
A breathing mask is a mask that covers the mouth, nose, and optionally other parts of the face or head, designed to constrain and direct the wearer's breath to and/or from a particular breathing apparatus. It may mean, or be part of, one of these types:
An oxygen mask is a mask that provides a method to transfer breathing oxygen gas from a storage tank to the lungs. Oxygen masks may cover only the nose and mouth or the entire face. They may be made of plastic, silicone, or rubber. In certain circumstances, oxygen may be delivered via a nasal cannula instead of a mask.
A hazmat suit is a piece of personal protective equipment that consists of an impermeable whole-body garment worn as protection against hazardous materials.
A snorkel is a device used for breathing atmospheric air when the wearer's head is face downwards in the water with the mouth and the nose submerged. It may be either a separate unit, or integrated into a swimming or diving mask. The integrated version is only suitable for surface snorkeling, while the separate device may also be used for underwater activities such as spearfishing, freediving, finswimming, underwater hockey, underwater rugby and for surface breathing while wearing scuba equipment. A standard snorkel is a curved tube with a shape usually resembling the letter "L" or "J", fitted with a mouthpiece at the lower end and made from plastic, synthetic elastomers, rubber, or light metal. The snorkel may have a loop or a clip to attach it to the head strap of the diving mask or swimming goggles, or may be tucked between the mask-strap and the head. Some snorkels are fitted with a float valve at the top to prevent flooding if the top opening is immersed, and some are fitted with a water trap and purge valve, intended for draining water from the tube.
The GP-5 gas mask kit is a Soviet-made gas mask kit, which contains a single-filter ShM-62 or Shm-62U gas mask. It was issued to the Soviet population starting in 1962 during the Cold War. Production of the kit ended in 1990. The number of GP-5 kits produced was three times more than the population of the Soviet Union. The GP-5 kit was originally made to protect the wearer from radioactive fallout from the Cold War and was distributed to most fallout shelters. They were tested in Poland to determine if they have NBC protective capabilities. It was concluded that the mask would last in an NBC situation for 24 hours.
An orinasal mask, oro-nasal mask or oral-nasal mask is a breathing mask that covers the mouth and the nose only. It may be a complete independent item, as an oxygen mask, or on some anaesthetic apparatuses, or it may be fitted as a component inside a fullface mask on underwater breathing apparatus, a gas mask or an industrial respirator to reduce the amount of dead space. It may be designed for its lower edge to seal on the front of the lower jaw or to go under the chin.
A breathing tube is a hollow component that can serve as a conduit for breathing. Various types of breathing tubes are available for different specific applications. Many of them are generally known by more specific terms.
The FM12 CBRN Respirator is a military gas mask produced by Avon Rubber.
The mechanism of diving regulators is the arrangement of components and function of gas pressure regulators used in the systems which supply breathing gases for underwater diving. Both free-flow and demand regulators use mechanical feedback of the downstream pressure to control the opening of a valve which controls gas flow from the upstream, high-pressure side, to the downstream, low-pressure side of each stage. Flow capacity must be sufficient to allow the downstream pressure to be maintained at maximum demand, and sensitivity must be appropriate to deliver maximum required flow rate with a small variation in downstream pressure, and for a large variation in supply pressure, without instability of flow. Open circuit scuba regulators must also deliver against a variable ambient pressure. They must be robust and reliable, as they are life-support equipment which must function in the relatively hostile seawater environment, and the human interface must be comfortable over periods of several hours.
Elastomeric respirators, also called reusable air-purifying respirators, seal to the face with elastomeric material, which may be a natural or synthetic rubber. They are generally reusable. Full-face versions of elastomeric respirators seal better and protect the eyes.
The GP-7 gas mask is a civilian gas mask that was produced by the Soviet Union during the Cold War era. The mask was designed to provide protection to civilians against nuclear, biological, and chemical (NBC) agents during the threat of the Cold War. Its military counterpart, the PMK was intended to be used exclusively for military purposes as opposed to the GP-7 which was designed solely for civil defense.
A breathing apparatus or breathing set is equipment which allows a person to breathe in a hostile environment where breathing would otherwise be impossible, difficult, harmful, or hazardous, or assists a person to breathe. A respirator, medical ventilator, or resuscitator may also be considered to be breathing apparatus. Equipment that supplies or recycles breathing gas other than ambient air in a space used by several people is usually referred to as being part of a life-support system, and a life-support system for one person may include breathing apparatus, when the breathing gas is specifically supplied to the user rather than to the enclosure in which the user is the occupant.
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