Page 51 - Demo

“Your Safer Source for Science”
Bulbs, Pipet
49
Bulbs, Pipet
See page 179.
Buret Rack, Flinn
The natural wood Flinn buret rack accepts 12 burets
up to 1" in diameter and measures 24" L x 21⁄2" W
x 24" H. Instead of your expensive burets rolling
around on a storeroom shelf, they are placed in the rack. The rack mounts on the chemistry lab wall with provided L-brackets (screws not included). A very valuable utilization tool to help protect and store expensive burets. Not for use with funnel top burets.
See free video at flinnsci.com.
Burets
Buret, Borosilicate Glass, with Glass Stopcock
This low cost, straight bore stopcock buret has permanent mark- ings that will last for years. The lines or graduations are sharp, fine and easy to read.
Buret, Borosilicate Glass, with PTFE Stopcock
A high-quality buret with a replaceable PTFE stopcock assembly. The delivery tip and buret sections are separate from the stopcock portion for easy replacement.
See free video at flinnsci.com.
Buret, Flint Glass, with PTFE Stopcock
A student quality buret with a PTFE stopcock. These are not Pyrex® glass burets but rather flint glass. The PTFE stopcock plug is ideal in the hands of a student because it is virtually freeze-proof.
Buret Rack, Flinn AP2288
Catalog No.
Description
Price/Each
AP2288
Buret Rack, Flinn
$58.05
Stopcock Grease
Plug Hole
Grease an All-Glass Stopcock
1. Clean the stopcock thoroughly.
2. Spread two circular bands of stopcock grease around the stopcock on either side of the plug hole.
3. Insert the stopcock in the buret and twist several times to spread out the grease.
4. Burets with PTFE stopcocks do not need to be greased.
Catalog No.
Capacity
Subdivisions
Price/Each
GP1080
50 mL
0.1 mL
$59.30
Catalog No.
Capacity
Subdivisions
Price/Each
Price/Case of 6
GP1089
25 mL
0.1 mL
$94.20
$525.84
GP1090
50 mL
0.1 mL
92.50
516.30
Catalog No.
Description
Price/Each
GP1092
Replacement Buret Body for Corning® GP1090
$50.15
GP1093
Replacement Buret Tips for Corning®
7.35
GP9150
Replacement PTFE Stopcock for Corning®
65.40
GP9168
Replacement Buret Body for LabGlass® GP1090
52.10
Buret,
Borosilicate Glass, with Glass Stopcock GP1080
See free video at flinnsci.com.
Catalog No.
Description
Size
Price/Each
Price/Case of 4
GP1086
Buret, Flint Glass, with PTFE Stopcock
25 mL
$65.45
$248.72
GP1087
50 mL
74.95
284.72
GP1088
100 mL
77.75
295.40
GP9188
Replacement Stopcock for Burets GP1086, GP1087, GP1088
24.30
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BURETS continued on next page.
Buret, Borosilicate Glass, with PTFE Stopcock GP1089, etc.
Buret, Flint Glass, with PTFE Stopcock GP1086, etc.
Free Frozen Stopcock Plugs
Always clean a buret with a glass stopcock after each use. Invariably the reason for a frozen buret plug is that it was not flushed thoroughly after the last use. Now you have a problem. Some suggested steps to free the plug:
• Immerse the entire barrel and plug in a glass or beaker of fresh soda pop. Allow the buret to soak until no more bubbles are seen. Frequently the gaseous bubbles will work their way into the joint and free it. Be patient enough to try this several times.
• If soda pop does not work, try applying a modest amount of heat. This can be done by setting a very low flame in a Tirrill- type burner (Catalog No. AP1019) and slightly warming the barrel while trying to move the stopcock. Wear heat-resistant gloves, and apply only a reasonable amount of pressure.
• If you still have no success, you may simply want to soak the buret in water for an extended period (several days).
• After soaking, try the soda pop process again; but if you fail again, it is fair to conclude that the ground glass surfaces of the plug and the barrel are fused with a contaminant and the buret will have to be replaced.
Frozen Glass Stopcock