US Alicat PCD double valve pressure controller using its own intake valve and relief valve fast and stable control of pressure in the closed container, Alicat unique design makes it not only the process gas is introduced into the cavity, the cavity pressure can Relief themselves too high. The equipment has been widely used in various fields, such as: semiconductor manufacturing and biopharmaceutical testing. US Alicat PCD double valve pressure controller is designed for a sealed container, high cost pressure control equipment. The conventional method of controlling the internal pressure of the sealed container is achieved by a pressure controller (or switch) and an exhaust port for this method, while feasible, but often leads to the waste of expensive gas, poor reproducibility and poor accuracy. US Alicat PCD double valve pressure controller via a modified PID loop control, it can be controlled and only two valves to allow one of them is turned on, this design allows fast and accurate pressure within the sealed container reaches the set value gas emission control in the same time will also be minimized. US Alicat PCD double valve pressure controller through improved response rate amount PID loop control, PCD series pressure controller can quickly and precisely reach a set value. Because of PCD and PC using a single control valve series similar calculations, measured obtaining control speed of less than 0.1 seconds. Reduce the cost of PCD series dual valve pressure controller allows only one valve is open, and automatically switches to the corresponding PID loop control valve. By the same time open and close a valve, greatly reducing for maintaining a set pressure value generated gases, i.e., reducing the waste gas. PCD Series switch double valve pressure controller, can save thousands of dollars in annual cost for users to purchase bottled gas. Control the use of the improved accuracy of PCD Series PID loop control and two proportional control valve, so that the standard control accuracy up to ± 0.25% FS, and another for high-precision matching. Modified PID loop and proportional control mode only enhance the system in a closed or nearly closed pressure control precision, but also eliminates the use of a pressure switch or other pressure shut-off valve controller peculiar blind spot. Repeatability generally modular design of process equipment, they use the instrument must be repeatable. PCD Series double valve pressure controller has amazing repeatability: ± 0.08% FS