Vacuum Catch Pot with Gauges. This pressure vessel is a must have for any composite work with vacuum. This unit has many benefits that will help your project work smoothly. This tank will act as a vacuum accumulator, which will allow you to hold a larger amount of vacuum. This works much like an air compressor, but in reverse. You would not buy an air compressor without a tank on it. The main purpose of this tank is to act as a catch or resin trap that will go in between the part and the vacuum pump, which ensures no resin is drawn into the pump. This tank has two fittings on it. One side connects to the part and the other side to the pump. This unit features industrial quality quick release fittings, as well as liquid filled guages to increase accuracy. This pot also has a vacuum relief valve on it, which allows you to fine tune your vacuum to the desired pressure, if needed.