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DG - 10/2019
Device Variants
4.5
Description of function
4.5.1
Description of function: Pressure actuated valve (2/2-way)
A slanting seat in the valve body will be closed with or against the flow direction by a valve disk.
The valve disk is connected with the piston by a stem. It`s dynamical sealing and guidance hap-
pens by a screw joint between valve body and pilot cylinder. The slanting valve design renders a
highly flow rate by low dirtyness.
Pressure actuated valves would be actuated wit a piston by a neutral pilot media (air, water, oil).
It works in a pressure range from 0 bar up to the max. nominal pressure which you can see in the
pressure table. The flow direction is fixed and signed on the valve.
4.4
Explosion proof identification
The pressure actuated valves are having an explosion proof identification, which shows the details
of the protection class to you:
Explosion proof identification of the pressure actuated valve:
Group
II
Category 2G/2D (for zone 1 and zone 21)
Explosion proof classification: h - constructional safety
Temperature class (max. temperature of the surface):
T4
:
T
max.
= 135°C
T5
:
T
max.
= 100°C
T6
:
T
max.
= 85°C
4.5
Corresponding use
Pressure actuated valves are work equipment with constructional safety designed for applicati-
ons in atmospheres according to category 2G (zone 1 + zone 2) / 2D (zone 21 + zone 22).
The max. temperature of the media, depending ot the switching frequency per minute, should not
exceed the following values:
85°C (n ≤ 5
/min
) / 40°C (n ≥ 60
/min
) at temperature class T6
100°C (n ≤ 5
/min
) / 65°C (n ≥ 60
/min
) at temperature class T5
135°C (n ≤ 5
/min
) / 100°C (n ≥ 60
/min
) at temperature class T4. (n: Open- Close- cycle)
The ambient temperature should not exceed 60°C.
By using the pressure actuated valves, observe that the flow rate of potentially explosive media
inside the pressure actuated valve will be less than:
v ≤ 2 m/s for potentially explosive liquids and
v ≤ 20 m/s for potentially explosive gaseous fluids.
II 2G Ex h IIC T4 Gb
II 2D Ex h IIIC T135°C Db
II 2G Ex h IIC T5 Gb
II 2D Ex h IIIC T100°C Db
II 2G Ex h IIC T6 Gb
II 2D Ex h IIIC T85°C Db
