ATEX UNLOADER AND RELIEF VALVES
SAFETY NOTE
SN03
Rev. 00
Date 27/10/2020
Pag. 7 of 10
The Company P.A. S.p.A. declines all responsibility for damage to persons, animals or things derived by an improper
use of the apparatus a/o the non-observance of the dispositions contained in the present manual.
3.4.3 DANGEROUS AREAS
Particular attention has to be reserved to any area potentially explosive around the valve and also from the inside. Do
not open the valve in areas potentially explosive and during working. Before opening the valve, disconnect it from the
machine and bring it to a safe area.
It is severely forbidden to operate on the tightening components and on the apparatus connections whilst running
and in any case each time it is predictable that the area may contain a potentially explosive ambient.
3.4.4 DANGER & POSSIBLE RISKS
Hot surfaces
The valves always present the danger of hot surfaces due to the maximum temperature of 90°C: always check that the
internal fluids and external areas cannot trigger off at such a temperature. The surface temperature must not be
higher than 80% of the minimum temperature ignition of the Gas measured in ° C.
Naked flames and hot gas
Naked flames and hot gas are forbidden around the valve.
Mechanical sparks
Sparks have to be excluded during a normal function even if they can occur in case of foreseen and rare dysfunctions;
they can be caused by friction, knocks or abrasion, hammering.
Ultrasounds (acoustic danger)
Tank measurement is forbidden when the valve is in function.
Electric currents and protection against cathode corrosion. Static electricity
Earth connect all the wires which could dangerously charge through certain connection points.
The installer is responsible for checking that there are no insulated metal parts.
The User must regularly check the effectiveness of the ground connection.
Adiabatic compression and shock waves
The process that can cause adiabatic compression or shock waves are not tolerated. Verify the normal function of the
wash fluid in the adduction systems.
Exothermic/Endothermic reactions, including self-ignition of powders
Wash fluids with endothermic characteristics or reactive with water and impurities are forbidden.
Excessive vibrations and stress
Stress derived from vibrations, especially transmitted by the tube connections and other connected apparatus are
forbidden; where such conditions cannot be guaranteed, appropriate measures must be taken to reduce to the
minimum such phenomena.
Back pressure
An elevated back pressure to the nozzles acts negatively on the valve compromising the set calibration. The nozzles
must be exempt from back pressure: They must not be blocked and no flow from the nozzles towards the inside of the
valve is permitted.
