Joint clips

Securingjlistillation-compppents do not. Pse plastjc joint clips on the ot end of a jdistiljatifin apparatus since they"rdayTnelt andThe jdints may-separate ... 

Attach the take-off adapter to the bottom of the condenser with a joint clip. If you are using a Quickfit- flask as a receiving flask, you must use a vacuum-type take-off adapter p. 42) otherwise you will be distilling in a closed system, which may explode when you begin to heat the distilling flask. 

Attach the Quickfit receiver flask to the take-off adapter with a joint clip or place the receiver flask underneath the take-off adapter, supported on a labjack or clamped position. The outlet of the take-off adapter must be just inside the receiving vessel so Itiat no spillage of distillate will occur. If... 

Attach the flask to the barrel and put plastic joint clips on all the joints, while supporting the flask with your hand. If the weight of the flask and contents springs any of the joints, k is too heavy replace it with a smaller flask or remove some of the solution. You must not rely on the power of the vacuum to hold your flask in place. 

When evaporation is complete, raise the flask from the bath, switch the motor off, open the vacuum inlet tap to allow air into the system and allow the flask to cool. Support the flask with your hand, take off the plastic joint clips, put the flask on one side and only then turn off the water pump. Turn off the water supply to the condenser. 

Plastic joint clips or Keck a clips (Fig. 5.22a) are used for holding ground-glass joints firmly together and may be used to replace clamps and support stands at certain points when building apparatus (see p. 109) and are essential when using rotary evaporators (p. 122). The main weakness of these otherwise useful devices is that they soften at about 130°C and this may allow the joints to separate. Therefore they should never be used at the hot end of a distillation, for example. The clip should be used to hold a distillation adapter on the end of a water condenser, or the flasks onto a fraction collector, but never on the distilling flask or to hold the condenser onto the still head (Fig. 5.22b). 

Securing distillation components - do not use plastic joint clips on the hot end of a distillation apparatus since they may melt and the joints may separate. 

The yellow slurry is stirred for 2-3 hours at — 15°. With rapid nitrogen flushing, the addition funnel is replaced with an adapter attached to a nitrogen line, the thermometer and mechanical stirrer are replaced with stoppers, and all joints are secured with standard-taper-joint clips (A. H. Thomas Co.). The apparatus shown in Fig. 1 is assembled and filled with nitrogen. The joints B and C are secured with standard-taper-joint clips. With nitrogen flushing through stopcock 1 and the reaction flask, the Dry Ice condenser is removed from the reaction flask and replaced by joint A the joint is secured with a joint clip. Care must be taken to support the reaction flask suitably, and it must be replaced in the cold bath. The filter is im-... 

The yellow slurry is recooled to —15° and slowly stirred for 2-3 h. With rapid nitrogen flushing, the addition funnel is replaced with an adapter attached to a nitrogen line, the thermometer and mechanical stirrer are replaced with stoppers, and all joints are secured with standard-taper-joint clips (A. H. Thomas Co.) or with electrical tape. The apparatus shown in... 

Assembling an apparatus in the correct manner requires that the individual pieces of glassware be connected to each other securely and the entire apparatus be held in the correct position. This can be accomplished by using adjustable metal clamps or a combination of adjustable metal clamps and plastic joint clips. 

When used in combination with metal clamps, the plastic joint clips make it much easier to assemble most apparatus securely. There is less chance of dropping the glassware while assembling the apparatus, and once the apparatus is set up, it is more secure. Figure 7.4 shows the same distillation apparatus held in place with adjustable metal clamps and plastic joint clips. 

Distillation apparatus secured with metal clamps and plastic joint clips. 

Joint clip/Joint clamp/ ground-joint clip/ ground-joint clamp Schliffklammer,... 

---