Vacuum is an important component of a rotary evaporater system. Upon usage, it is equally important to make sure your system works well and maintain vacuum – in order to do task on time we will repair it by the tricks given in this post and that it maintains the pressure and does not leak outside air into the system.
There are several reasons why a Rotary Evaporator system might not maintain vacuum
Leaks may majorly occur at the seals (called vacuum seal for rotavapor) where your condenser connects with the body of the rotary evaporator near the upper end of the vapor tube. Sometimes you can listen for leaks by placing your ear near glass joints and connections, but many times the vacuum pump is loud enough that small leaks may not be detectable this way.
If you disconnect your pump and use a vacuum gauge directly on the pump. It can check the pump is working fine or not and give the value of maximum vacuum describes by the instruction manual of the pump.
You can repair the vacuum Seal by your own by inserting a small rubber band inside the space in the vacuum Seal and check after fitting it in condenser system to main unit.You have to open the Joint by hand smoothly and then remove the seal to insert the rubberband.It will work like new if you can fit the rubber in sufficiently good condition.Hope you find the resolution of the problem. And saved 100$ (~8000₹) on this topic.