Ex p Control unit
SILAS
pz
Installation
Rev. 0
A1-37S2-7D0001_pz_Manual_Exp-Control-Unit_20210923_0_en.docx
Page 25 of 88
Installation purging gas supply
ATTENTION
MATERIAL DAMAGE CAUSED BY THE ABSENCE OF A PURGE GAS NOZZLE.
Due to the build-up of internal pressure, there is a risk of excessive strain on
the pressurized enclosure.
Check if the purge gas nozzle is there.
NOT ENOUGH PURGING GAS DUE TO UNDERDIMENSIONED
PURGING GAS SUPPLY LINE.
Pressurized enclosure does not go into operation due to low flow
rate.
Adjust the inner diameter of the purging gas supply line to
the required flow rate.
The purge gas supply is composed of a pressure reducer, a purge gas valve and a
purge gas nozzle. Depending on the capacity of the pressurized enclosure, the
purge gas supply is available in the sizes G1/4” or G1/2”.
The following table shows a guideline value in terms of protected volumes.
Capacity
Pre
Pressure
Pressure
reducer
Pressure
outlet
Purge gas
nozzle
Feeding
pipe
< 50 liters
2 bar
¼“
1x
2.8 mm
10 mm
50 to 300
liters
2 bar
¼“
1x
3.9 mm
10 mm
300 to 700
liters
2 bar
¼“
1x
4.2 mm
15 mm
700 to 1000
liters
3 bar
½“
2x
4.5 mm
15 mm
As of 1000
liters
3 bar
½“
2x
5.5 mm
20 mm
(The levels specified in the table are reference values and can vary.)
The pressure reducer for lowering the pressure of the supplied purge gas is
mounted on the outside of the pressurized enclosure. The purge gas valve, which
releases the purge gas, is mounted inside the pressurized enclosure. The purge
gas nozzle restricts the maximum flow of the purge gas and accordingly prevents
pressure increasing to the maximum level inside the pressurized enclosure when
a purge gas valve is defective.
The following shows the assembly of the purge gas supply. The required
assembly material is included in the scope of supply.
