Stopper plug

Stopfen, n. stuffing, etc. (see stopfen) stopper, plug, cork. 

Stdpsel, m. stopper, plug, cork, -flasche, /. stoppered bottle (or flask), -glas, n. stoppered glass, -hahn, m. stopper cock, cock stopper. -hasten, m. (Elec.) resistance box. 

The Stopper Plug. There are two types of ground stoppers reagent bottle stoppers and flask stoppers. They have the same 1 10 taper as the joints previously mentioned, however, they are listed by only one number based on their width measurement (see Fig. 3.7). Both stopper types have a flattened disk above the ground section for easy holding. Because the term pennyhead stoppers can refer to either reagent or flask stoppers, a complete description of the stopper you want is important for complete identification. 

Round-Bottom Flasks, Pennyhead Stoppers, Plugs, and Other Loose Items. Many items are stored in drawers and (as the drawer is opened and closed) can bang around. This situation applies especially to round-bottom flasks, which are hard to prevent from rolling around. When these flasks bang around, star cracks, or flaws for future fracture, are created. For round-bottom flasks, Erlenmeyer... 

In a 250 ml. separatory funnel place 25 g. of anhydrous feri.-butyl alcohol (b.p. 82-83°, m.p. 25°) (1) and 85 ml. of concentrated hydrochloric acid (2) and shake the mixture from time to time during 20 minutes. After each shaking, loosen the stopper to relieve any internal pressure. Allow the mixture to stand for a few minutes until the layers have separated sharply draw off and discard the lower acid layer. Wash the halide with 20 ml. of 5 per cent, sodium bicarbonate solution and then with 20 ml. of water. Dry the preparation with 5 g. of anhydrous calcium chloride or anhydrous calcium, sulphate. Decant the dried liquid through a funnel supporting a fluted Alter paper or a small plug of cotton wool into a 100 ml. distilling flask, add 2-3 chips of porous porcelain, and distil. Collect the fraction boiling at 49-51°. The yield of feri.-butyl chloride is 28 g. 

Stopper the side arm of a 25 or 50 ml. distilling flask and fit a vertical water condenser into the neck. Place 0-5-1 -0 g. of the dry acid (finely powdered if it is a solid) into the flask, add 2-5-5 0 ml. of redistilled thionyl chloride and reflux gently for 30 minutes it is advisable to place a plug of cotton wool in the top of the condenser to exclude moisture. Rearrange the condenser and distil off the excess of thionyl chloride t (b.p. 78°). The residue in the flask consists of the acid chloride and can be converted into any of the derivatives given below. 

Containers should be clear in order to allow detection of foreign particles. Outer coverings minimize irradiation. Plugs used as stoppers are selected with care to prevent flaking into the contents and possible component leaching into the product. 

A Calcium Chloride U-Tube.—The form of calcium chloride tube is sho%vn in Fig. 8. It is fitted with sieved calcium chloride to within 2 cm. (i in.) of the side pieces, and then with coarser pieces to within cm. (J in.). Place a small plug of cotton wool in both limbs above the chloride to keep it in position. Two well-fitting corks, cut off level with the glass and coated with sealing-wax, produce an effective air-tight stopper to the open limbs, but it is preferable to seal... 

Hahn-hulse, /. (stop)cock shell or barrel -kegel, m., -kUken, -kiicken, n. (stop)cock plug or stopper, -messer, m. flowmeter, -schllissel, m. cock wrench, cock spanner, -sitz, m. (stop)cock seating or seat, -stopfen, n., -stdpsel, m. (stop)cock stopper or plug, -trichter, m. funnel with stopcock. 

Kiiken, n. (stop)cock plug or stopper (sometimes) stopcock chicken, chick. -Hahn, m. stopcock. 

Ventil-kiiken, m. valve plug. -SI, n. valve oil. -schlauch, m. valve tubing, -sitz, m. valve seat. -Stahl, m. valve steel, -stopfen, n. stopper with a valve, valve stopper, -zelle,/. (Elec.) valve cell. 

The construction of two typical infrared cells is shown in Fig. 19.6. Such cells have to be carefully filled by using a syringe or Pasteur pipette to ensure that no air is trapped inside. To prevent evaporation the ports should be plugged with small plastic stoppers once the cell has been filled with the solution. 

Figure 28, Modification of the Conway technique using rotated bottles in pkwe of the Conway diffusion dish, 1, bottle with a rubber stopper and glass plug containing an edged end which has been dipped in sulfuric acid 2, roughed end of the glass plug 3, rotator with clips holding the bottles in place.

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