When glass is used for both the stopcock body and the plug, the contacting surfaces between them are special ground glass surfaces (see Laboratory glassware) often with stopcock grease in between. Special glass stopcocks are made for vacuum applications, such as in use with vacuum manifolds. Stopcock grease is always used in high vacuum applications to make the stopcock air-tight. Also if the plug valve is "locked" from being in the open or closed position for an extended amount of time lubricant can be added through the greaser with the valve in service.
|
|
Page 3 shows Mohr's burette; page 12 shows a burette with a glass stopcock (Glasshahn).
|
|
A volumetric burette can be made of glass or plastic, and is a straight tube with a graduation scale. At the tip of burette, there are a stopcock and valve to control the flow of the chemical solution. The barrel of the stopcock can be made of glass or the plastic PTFE. Stopcocks with glass barrels need to be lubricated with vaseline or a specialized grease.
|
|
Gas is evolved from this reaction, which may be drawn off through the stopcock as desired. When the stopcock is closed, the pressure of the evolved gas in the middle chamber rises and pushes the acid back down into the bottom chamber, until it is not in contact with the solid material anymore. At that point the chemical reaction comes to a stop, until the stopcock is opened again and more gas is drawn off. Kipp generators only work properly in the described manner if the solid material is insoluble in the acid, as otherwise the dissolved material would continue to evolve gas even after the level dropped.
|
|
Medical Devices Manufacturing The main products are PTCA accessories including balloon in- deflation device, control syringes, manifolds, Y connector pack, pressure lines and 3 way stopcock.
|
|
One of Elcam Medical's single-use disposable device, labelled as their "Stopcock".There are many manufacturing companies that produce and reprocess single use medical devices safe and efficiently.
|
|
The sloping sides are designed to facilitate the identification of the layers. The stopcock-controlled outlet is designed to drain the liquid out of the funnel. On top of the funnel there is a standard taper joint which fits with a ground glass or Teflon stopper. To use a separatory funnel, the two phases and the mixture to be separated in solution are added through the top with the stopcock at the bottom closed.
|
|
A pear-shaped Schlenk flask. The flask's sidearm contains a greased stopcock valve, and the flask is capped with a Suba•Seal septum that has not been turned down. The standard Schlenk flask is a round bottom, pear-shaped, or tubular flask with a ground glass joint and a side arm. The side arm contains a valve, usually a greased stopcock, used to control the flask's exposure to a manifold or the atmosphere.
|
|
50px A burette (also buret) is a graduated glass tube with a tap at one end, for delivering known volumes of a liquid, especially in titrations. It is a long, graduated glass tube, with a stopcock at its lower end and a tapered capillary tube at the stopcock's outlet. The flow of liquid from the tube to the burette tip is controlled by the stopcock valve. There are two main types of burette; the volumetric burette and the Piston burette or Digital burette.
|
|
When current is run through the Hofmann voltameter, gaseous oxygen forms at the anode (positive) and gaseous hydrogen at the cathode (negative). Each gas displaces water and collects at the top of the two outer tubes, where it can be drawn off with a stopcock.
|
|
A common straight bore glass stopcock attached with a plastic plug retainer in the side arm of a Schlenk flask. When using glassware it is often necessary to control the flow of fluid. It is commonly stopped with a stopper. Fluid may be transported between connected pieces of glassware.
|
|
Thereafter he not only omitted to close the stopcock, but also omitted properly to replace the filler cap. As a result, diesel escaped from the main fuel tank onto the road surface, thus causing the accident. One person suffered injuries and another died as a result of the accident.
|
|
A stopcock is a form of valve used to control the flow of a liquid or gas. The term is not precise and is applied to many different types of valve. The only consistent attribute is that the valve is designed to completely stop the flow when closed fully.
|
|
View from above an empty Imhoff Tank. A test for settleable solids in water, wastewater and stormwater uses an Imhoff cone, with or without stopcock. The volume of solids is measured after a specified time period at the bottom of a one-liter cone using graduated markings. Imhoff Cone, Retrieved 2012-05-29.
|
|
Two procedures for degassing are common. The first is known as freeze-pump-thaw -- the solvent is frozen under liquid nitrogen, and a vacuum is applied. Thereafter, the stopcock is closed and the solvent is thawed in warm water, allowing trapped bubbles of gas to escape. The second procedure is to simply subject the solvent to a vacuum.
|
|
Empty Kipp's apparatus, with stopcock and fermentation lock.Drawing of a filled Kipp's apparatus.Kipp's apparatus, also called Kipp generator, is an apparatus designed for preparation of small volumes of gases. It was invented around 1844 by the Dutch pharmacist Petrus Jacobus Kipp and widely used in chemical laboratories and for demonstrations in schools into the second half of the 20th century.
|
|
In the context of cannula transfer, mercury bubblers may be avoided by pulling (instead of pushing) liquids through the cannula by vacuum. Alternatively, the oil bubbler may be closed off from the inert gas line with a stopcock, allowing inert gas to push the reagent through the cannula. Excess pressure is bled off from a bubbler fitted directly over the receiving vessel.
|
|
In addition to his isolation and study of germanium, Winkler investigated the analysis of gases. He published a book on the subject, Handbook of Technical Gas Analysis, in 1884. In that book Winkler describes his invention of the three-way stopcock. He predicted the existence of silicon monoxide, SiO, and was the first to attempt to produce it by heating silica with silicon in 1890.
|
|
City of Birmingham Water Department sign at Perry Barr Reservoir Domestic stopcock cover set into the pavement outside a house in north Birmingham, with the initials "CBWD" Birmingham Corporation Water Department existed until 1974 when, under the Water Act 1973, its responsibilities were transferred to the Severn Trent Water Authority which is now Severn Trent Water. The city council later took unsuccessful legal action to recover its lost investment.
|
|
Types of interconnecting components include glass tubing, T-connectors, Y-connectors, and glass adapters. For a leak-tight connection a ground glass joint is used (possibly reinforced using a clamping method such as a Keck clips). Another way to connect glassware is with a hose barb and flexible tubing. Fluid flow can be switched selectively using a valve, of which a stopcock is a common type fused to the glassware.
|
|
Station Officer Steele fires Elvis Cridlington as the station cook. This gives Fireman Sam an idea; He invents Pancake Prototype One and a robot called Bentley to be Elvis' replacement ("Gently, Bentley"). Whilst spring-cleaning, Elvis, exasperated with Bentley's constant whistling, decides to place his Elvis Presley cassette into the robot. This causes Bentley to malfunction and ends up breaking the stopcock, causing a flood inside the fire station.
|
|
A separating funnel takes the shape of a cone with a hemispherical end. It has a stopper at the top and stopcock (tap), at the bottom. Separating funnels used in laboratories are typically made from borosilicate glass and their stopcocks are made from glass or PTFE. Typical sizes are between 30 mL and 3 L. In industrial chemistry they can be much larger and for much larger volumes centrifuges are used.
|
|
The top must be opened while releasing the lower phase to allow pressure equalization between the inside of the funnel and the atmosphere. When the bottom layer has been removed, the stopcock is closed and the upper layer is poured out through the top into another container. organic phase (yellow, upper phase) has a lower density than the aqueous phase (lower phase). The aqueous phase is being drained into the beaker.
|
|
When using Schlenk systems, including flasks, the use of grease is often necessary at stopcock valves and ground glass joints to provide a gas tight seal and prevent glass pieces from fusing. In contrast, teflon plug valves may have a trace of oil as a lubricant but generally no grease. In the following text any "connection" is assumed to be rendered mostly air free through a series of vac-refill cycles.
|
|
A stand of lamps adapted to the reception, emission, and burning of the gas was next invented and constructed by Mr. Hart. These consisted of several horizontal arms extended like the radii of a semicircle, at the end of each of which a brass pipe was attached. The quantity of gas consumed by each burner was regulated by a stopcock. Each burner had a large and suitable reflector.
|
|
Like a ground glass stopcock, the two parts of a gas syringe should preferably not be interchanged with another gas syringe of the same volume, unless told otherwise by the distributor. Gas syringes come in various sizes from 500 ml to 0.25 ml and tend to be accurate to between 0.01 and 1 ml, depending on the size of the syringe.Valco. "Gas/Liquid Syringes." Valco Instruments Company Incorporated.
|
|
This can result in destruction of the engine. There is normally a bung or stopcock that allows draining of the crankcase before starting. The lack of valves and the doubled-up working cycle also means that a two-stroke hot-bulb engine can run equally well in both directions. A common starting technique for smaller two-stroke engines is to turn the engine over against the normal direction of rotation.
|
|
In April 2014, Polypipe was the subject of an initial public offering on the London Stock Exchange. Then in November 2014, Polypipe acquired the Ferrob Ventilation business. In February 2015, Polypipe acquired Surestop, a business producing an alternative product to the brass stopcock, and in August 2015 Polypipe acquired Nuaire, a ventilation systems manufacturer. It was announced in May 2017 that Martin Payne will succeed David Hall as the CEO following his retirement.
|
|
Balanced ailerons extended throughout the span, except near the fuselage, where these were reduced to provide greater downward visibility for the pilot. The lower wing surface sat only 1.5 m (4.92 ft.) above the ground, which generated a beneficial ground effect to significantly reduce landing speeds. The aircraft's fuel tanks, which were located in the wing's center portion on either side of the axis of symmetry, could be separately isolated using a multi-way stopcock.
|
|
A vacuum desiccator (left - note the stopcock which allows a vacuum to be applied), and a desiccator (right). The blue silica gel in the space below the platform is used as the desiccant. Desiccators are sealable enclosures containing desiccants used for preserving moisture-sensitive items such as cobalt chloride paper for another use. A common use for desiccators is to protect chemicals which are hygroscopic or which react with water from humidity.
|
|
Indication gels typically change from blue to pink as they absorb moisture but other colours may be used. A stopcock may be included to permit the desiccator to be evacuated. Such models are usually known as vacuum desiccators. When a vacuum is to be applied, it is a common practice to criss-cross the vacuum desiccator with tape, or to place it behind a screen to minimize damage or injury caused by an implosion.
|
|
Inert gas lines are usually vented out of a gas bubbler placed in-line to prevent overpressure. The vents need to be isolated by capping the bubbler outlet, or stopping the egress of inert gas with a stopcock or pinch clamp, to ensure sufficient pressure to complete the transfer. The use of a mercury bubbler instead of one filled with oil used to be popular, but is out of favor due to the difficulty in dealing with mercury spills.
|
|
The grandfather of Richard Haddock, also a sea captain, commanded the ship of the line HMS Unicorn during the reign of Charles I. Bianca Castafiore has a difficult time remembering Haddock's name. In The Castafiore Emerald. she confuses his name with malapropisms such as "Paddock", "Harrock", "Padlock", "Hopscotch", "Drydock", "Stopcock", "Maggot", "Bartók", "Hammock", and "Hemlock". The fictional Haddock remained without a first name until the last completed story, Tintin and the Picaros (1976), when the name Archibald was suggested.
|
|
A Schlenk line with four ports. The cold trap is on the right Close-up view, showing the double-oblique stopcock, which allows vacuum (rear line) or inert gas (front line) to be selected The Schlenk line (also vacuum gas manifold) is a commonly used chemistry apparatus developed by Wilhelm Schlenk. It consists of a dual manifold with several ports. One manifold is connected to a source of purified inert gas, while the other is connected to a vacuum pump.
|
|
Harrison, J. F. C., Robert Owen and the Owenites in Britain and America (Routledge and Kegan Paul, 1969) pp. 103/4. Combe continued to proselytise on Owen's behalf by writing pamphlets and books. These included Metaphorical Sketches of the Old and New Systems (1823), in which he satirically attacked the prevailing capitalist economic theories by comparing the British economy to a cistern, which was capable of supplying the wants of the entire nation until the guardians of the stopcock cut off supply.Beer, Max.
|
|
A collision had occurred between two vehicles when one of them skidded on diesel that had spilled from a truck belonging to the second defendant. The truck had broken down alongside the road. It appeared that, after the truck had broken down, the driver, supposing that there was a problem with the vehicle's fuel supply, opened a stopcock, which permitted diesel fuel to flow into the main fuel tank from another tank. He also opened the filler cap of the main fuel tank, to inspect its interior.
|
|
A Schlenk flask, or Schlenk tube is a reaction vessel typically used in air- sensitive chemistry, invented by Wilhelm Schlenk. It has a side arm fitted with a PTFE or ground glass stopcock, which allows the vessel to be evacuated or filled with gases (usually inert gases like nitrogen or argon). These flasks are often connected to Schlenk lines, which allow both operations to be done easily. Schlenk flasks and Schlenk tubes, like most laboratory glassware, are made from borosilicate glass such as Pyrex.
|
|
The side-float design uses a float on the end of a lever to control the fill valve. The float is usually shaped like a ball, so the mechanism is often called a ball-valve or a ballcock (cock in this context is an alternative term for valve; see, for example, stopcock). The float was originally made from copper sheet, but it is now usually plastic. The float is located to one side of the main valve tower or inlet at the end of a rod or arm.
|
|
Crick was told to write a note to Mr Young, one of the partners of the brewery, to have it fixed later. An hour after the hoop fell off, Crick was standing on a platform from the vat, holding the note to Mr Young, when the vessel, with no indication, burst. The force of the liquid's release knocked the stopcock from a neighbouring vat, which also began discharging its contents; several hogsheads of porter were destroyed, and their contents added to the flood. Between 128,000 and 323,000 imperial gallons were released.
|
|
The very reason why the driver had removed the filler cap of the main fuel tank was because he had experienced trouble while driving the truck. His act in opening the stopcock and removing and replacing the filler cap was intended to rectify the problem, and to allow him to continue driving the vehicle. The direct result of that ancillary act was the spilling of the diesel, which caused the accident and the resultant damage. In the circumstances, common sense dictated that the death and injuries had arisen from the driving of G the second defendant's truck.
|
|
Amalgamated zinc is first prepared by treating zinc metal with a 2% solution of mercury(II) chloride, in a beaker. The metal may be in the granulated form or as shavings, wool, or 20-30 mesh powder. The mercury ions are able to penetrate the passive layer and are reduced to elemental mercury, forming the amalgam, which is a kind of alloy of both metals, on the metal surface. The amalgam is thoroughly washed by decantation and placed in a long glass tube, similar to a chromatography column, equipped with a stopcock and a means to support the amalgam, such as a sintered-glass disk.
|
|
As part of current research efforts artificial photonic antenna systems are being studied to determine efficient and sustainable ways to collect light for artificial photosynthesis. Gion Calzaferri (2009) describes one such antenna that uses zeolite L as a host for organic dyes, to mimic plant's light collecting systems. The antenna is fabricated by inserting dye molecules into the channels of zeolite L. The insertion process, which takes place under vacuum and at high temperature conditions, is made possible by the cooperative vibrational motion of the zeolite framework and of the dye molecules. The resulting material may be interfaced to an external device via a stopcock intermediate.
|
|
A Dean–Stark apparatus in use; aluminium foil is used to reduce heat losses Two types of Dean–Stark traps exist – one for use with solvents with a density less than that of water and another for use with solvents with a density greater than that of water. The Dean–Stark apparatus typically consists of a vertical cylindrical glass tube, often with a volumetric graduation along its full length and a precision stopcock at its lower end, very much like a burette. The lower end of a reflux condenser fits into the top of the cylinder. Immediately below the joint between the condenser and the cylinder is a sloping side-arm that joins the cylinder to a reaction flask.
|
|
When attached to certain functional groups in a reactant molecule, trimethylsilyl groups may also be used as temporary protecting groups during chemical synthesis or some other chemical reactions. In chromatography, derivitization of accessible silanol groups in a bonded stationary phase with trimethylsilyl groups is referred to as endcapping. In an NMR spectrum, signals from atoms in trimethylsilyl groups in compounds will commonly have chemical shifts close to the tetramethylsilane reference peak at 0 ppm. Also compounds, such as high temperature silicone "stopcock" grease, which have polysiloxanes (often called silicones) in them will commonly show peaks from their methyl groups (attached to the silicon atoms) having NMR chemical shifts close to the tetramethylsilane standard peak, such as at 0.07 ppm in CDCl3.
|
|
She often confuses words, especially names, with other words that rhyme with them or of which they remind her; "Haddock" is frequently replaced by malapropisms such as "Paddock", "Stopcock", or "Hopscotch", while Nestor, Haddock's butler, is confused with "Chestor" and "Hector". Her own name means "white and chaste flower": a meaning to which Professor Calculus once refers when he breeds a white rose and names it for the singer. She was based upon opera divas in general (according to Hergé's perception), Hergé's Aunt Ninie (who was known for her "shrill" singing of opera), and, in the post-war comics, on Maria Callas. Other recurring characters include Nestor the butler, Chang (or Chang-Chong -Chen in full) the loyal Chinese boy, Rastapopoulos the criminal mastermind, Jolyon Wagg the infuriating (to Haddock) insurance salesman, General Alcazar the South American freedom fighter and President of San Theodoros, Mohammed Ben Kalish Ezab the Arab emir, and Abdullah his mischievous son, Dr. Müller the evil German psychiatrist, Oliveira da Figueira the friendly Portuguese salesman, Cutts the butcher whose phone number is repeatedly confused with Haddock's, and Allan the henchman of Rastapopoulos and formerly Haddock's first mate.
|
|