Glasse connectivities

The mercury-cup seals may be replaced by ground-glass joints lubricated with a very small amount of 85% phosphoric acid. If ground-glass connections are used the inlet and outlet... 

Another example a solvent was put into a small reactor to remove some polymer, which was stuck to the walls. Some monomer, which was trapped behind the polymer, reacted with the solvent, and the pressure rose. Bits of polymer plugged the relief valve, and the pressure broke a glass connecting line [8]. 

The cell is hermetically sealed. This is performed by a glass connection from the / "-alumina ceramic tube to a ring of a-alumina. Metal parts are connected to the a -alumina by thermocompression bonding and the metal parts are either con-... 

Glass connections or rubber stoppers should be used throughout, as corks are rapidly disintegrated by the hot bromine. 

Using standard taper jointware you can connect glassware without rubber stoppers, corks, or tubing. Pieces are joined by glass connections built into the apparatus (Fig. 17). They are manufactured in standard sizes, and you ll probably use T19/22. 

Rubber stoppers are used throughout. Tightly fitting ground-glass connections are convenient but unnecessary. The third neck of the flask is used when acid chlorides are prepared from the corresponding acids (Note 9). 

With all gasometric methods it is vital that all the connections and stoppers are gas-tight and usually these glass-to-glass connections are lubricated with lanolin grease. However, it requires very careful technique to ensure that the system is leak-proof and it is desirable to test for leaks once a system has been set up and prior to initiating the reaction. 

Teflon sleeves are used to assure the vacuum tight connection between the ground joints subjected to heat. The checkers used clear-seal joints in all of the glass connections. 

Specifically, the glass connection between the Schlenk tube receiver (C) and stopcock (D) should extend about 130 mm below the top of the 24/40 standard taper inner joint and approximately 50 mm into Dewar flask (E) to prevent loss of the especially volatile V(CO)e to the vacuum line during the reaction and sublimation. The Schlenk tube receiver is cooled to about —70°C with dry ice/acetone or dry ice/isopropyl alcohol. The level of coolant should be near the top of the Dewar so that the glass connection between the stopcock (D) and the Schlenk tube is entirely covered. The apparatus is evacuated very slowly and cautiously... 

Best results are obtained if an all-glass apparatus with ground-glass connections is used, as noted by Wawzonek and Karll.4... 

Figure 18.4 Threaded glass connection that consists of a threaded outer tube, a threaded bushing, and an O-ring.

A flask fitted with a ground-glass connection to the reflux condenser will assist in reduc ing the amount of tar. 

It is usually necessary to remove the flask and delivery tube from the furnace and to heat the ground-glass connection gently in order to get it apart. The product is quickly transferred to dry containers which can be stoppered tightly. ... 

Apparatus Use a glass distillation apparatus (see Fig. 8) provided with 24/40 ground-glass connections. The components consist of a 500-mL short-neck, round-bottom flask connected by means of a trap to a 400-mm water-cooled condenser. The lower tip of the condenser should be about 7 mm above the surface of the liquid in the trap after distillation conditions have been established (see Procedure). 

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