The Type 40 is a series of flow-through annular replaceable diaphragm seals from Noshok. It functions by processing liquid flowing through the pipe and exerts pressure onto a flush-mounted flexible inner cylinder that contains clean and captive fluid. It completely isolates the instrumentation from the process flow and avoids plugging. This device can be removed for calibration, repair, or replacement without interrupting the process flow. It has a durable design that does not break easily and makes this seal usable for various process conditions in many applications.