WIKA 762.14 - Manual (Page 6)

6
Temperature Class of the
ambient atmosphere
(ignition temperature)
Maximum permissible medium temperature
(in the pressure system)
T 6 (85 °C < T ≤ 100 °C) +70 °C
T 5 (100 °C < T ≤ 135 °C) +85 °C
T 4 (135 °C < T ≤ 200 °C) +100 or +120 °C
1)
T 3 (200 °C < T ≤ 300 °C) +100 or +185 °C
1)
T 2 (300 °C < T ≤ 450 °C) +100 or +200 °C
1)
T 1 (T > 450 °C) +100 or +200 °C
1)
GB
WIKA Operating instructions pressure gauges Model 7 per ATEX
2080284.06 10/2013 GB/D/F
Operating Temperature
Ambient: -20 ... +60 °C
with option silicone oil filling: -40 ... +60 °C
Medium: The permissible medium temperature does not only depend on the
instrument design, but also on the ignition temperature of the
surrounding explosive atmosphere. Both aspects must be taken
into account.
For maximum permissible medium temperatures see Table 2.
Attention! In the case of gaseous substances, the temperature may increase
due to compression warming. In these cases it may be necessary to throttle
the rate of change of pressure or reduce the permissible temperature of the
pressure medium.
Table 2: Permissible medium temperature
1) The higher values only apply to special versions with higher permissible media temperatures.
Materials
Wetted parts: Pressure connections and pressure chamber: stainless steel
(Model 73x.51/31) Pressure element ≤ 0.25 bar: stainless steel
> 0.25 bar: NiCr-alloy (Inconel)
Air bleeding plugs:
stainless steel (option: ranges ≥ 0,4 bar)
Wetted parts: Pressure connections and pressure flanges: stainless steel
(Model 73x.14) Pressure elements: stainless steel/NiCr-alloy (Inconel)
Sealing rings: FPM/FKM
Venting of the pressure chambers:
stainless steel (option: ranges ≥ 0,4 bar)
3. Technical data and intended use