Pressure switches of the DNS series are suitable for monitoring and controlling pressures in chemical plants, process engineering and any situation where the pressure of aggressive liquids and gases must be monitored. All components of the sensor system are made of highquality stainless steel (1.4571) and welded using the latest methods without filler metals. The pressure sensor is gasket free plasma welded.

Pressure switch for aggressive liquid, gas (DNS)

DNS3-201 Product Summary * At very high vacuums, close to the theoretical maximum of –1 bar, the switch may not be usable in view of the special conditions of vacuum engineering. However, the pressure switch itself will not be damaged at maximum vacuum. Calibration The DNS and VNS series are calibrated for falling pressure. This means that the adjustable switching pressure on the scale corresponds to the switching point at falling pressure. The reset point is higher by the amount of the switching differential. (See also page 23, 1. Calibration at lower switching point). -DNS/VNS see page 63 Technical data Pressure connection External thread G 1/2 (pressure gauge connection) according to DIN 16 288 and internal thread G 1/4 according to ISO 228 Part 1. Switching device Robust housing (200) made of seawater resistant die cast aluminium GD Al Si 12. Protection class IP 54, in vertical position. Pressure sensor materials Pressure bellows and all parts in contact with medium. X 6 Cr Ni Mo Ti 17122 Material no. 1.4571 Mounting position Vertically upright and horizontal. Max. ambient temperature at switching device –25…+70 °C. Max. medium temperature The maximum medium temperature at the pressure sensor must not exceed the permitted ambient temperature at the switching device. Temperatures may reach 85°C for short periods. Higher medium temperatures are possible provided the above limit values for the switching device are ensured by suitable measures (e.g. siphon). Mounting Directly on the pressure line (pressure gauge connection) or on a flat surface with two

DNS/VNS Pressure and vacuum switches with stainless steel sensors (1.4571)Type Setting range Switching differential (Tolerance) Max. permissible pressure Dimensioned drawing Hysteresis not adjustable page 21 + 22 VNS301-351 -250…+100 mbar 30 ... 60mbar 3bar VNS111-351 -1*…+0,1 bar 30 ... 70mbar 6bar DNS025-351 0,04…0,25bar 20 ... 40mbar 6bar 2 + 15 DNS06-351 0,1…0,6bar 10 ... 50 mbar 6bar DNS1-351 0,2…1,6bar 40 ... 80 mbar 6bar DNS3-351 0,2…2,5bar 60 ... 140mbar 16bar 2 + 18 DNS6-351 0,5…6bar 0,07 ... 0,23bar 16bar DNS10-351 1…10bar 0,2 ... 0,4bar 16bar 2 + 17 DNS16-351

Definitions Pressure data Overpressure Pressure over the relevant atmospheric pressure. The reference point is atmospheric pressure. Vacuum Pressure under the relevant atmospheric pressure. The reference point is atmospheric pressure. Absolute pressure Overpressure relative to absolute vacuum. Differential pressure Difference in pressure between 2 pressure measuring points. Relative pressure Overpressure or vacuum relative to atmospheric pressure. Pressure data in all FEMA documents refers to relative pressure. That is to say, it concerns pressure differentials relative to atmospheric pressure. Overpressures have a positive sign, vacuums a negative sign. Permissible working pressure (maximum permissible pressure) The maximum working pressure is defined as the upper limit at which the operation, switching reliability and water tightness are in no way impaired (for values see Product summary). Bursting pressure (test pressure) Type-tested products undergo a pressure test certified by TÜV affirming that the bursting pressure reaches at least the values mentioned in the Product summary. During the pressure tests the measuring bellows are permanently deformed, but the pressurized parts do not leak or burst. The bursting pressure is usually a multiple of the permissible working pressure. Setting range Pressure range in which the cutoff pressure can be set with the setting spindle. Pressure units Important: All pressure data refers to overpressures or vacuums relative to atmospheric pressure. Overpressures have a positive sign, vacuums a negative sign. In FEMA documents pressures are stated in bar or mbar. Pressure data for a pressure switchbased on the example of DWR625: Setting range: 0.5-6 bar Perm. working pressure: 20 bar Bursting pressure: >100 bar Unit bar mbar Pa kPa MPa (psi) Ib/m² 1 bar 1 1000 10⁵ 100 0.1 14.5 1 mbar 0.001 1 100 0.1 10-4 0.0145 1 Pa 10-5 0.01 1 0.001 10-6 1.45 · 10-4 1 kPa 0,01 10 1000 1 0.001 0,145 1 MPa 10 104 106