Type 6518 is a pilot-operated 3/2-way valve and Type 6519 is a 3/2, 5/2 or 5/3-way valve. Together they form a series. The valves can be used individually or on blocks. They operate without continuous air consumption and are used to control single- or double-acting actuators. The use of high-quality materials allows the valves to be used even in outdoor and chemically aggressive environments. The series includes devices with Ex approval and NAMUR flange design. With the monostable valve circuit functions C, D, and H, a safety level of SIL2 can be achieved in accordance with IEC 61508, depending on the architecture of the safety system.