Safety relief valves
33501, 33502, 33503, 33521, 33601, 33602, 33603, 33621
Operation
Warning – General hazards!
If the pressure system is exposed to a higher fluid temperature, the surface
temperature of the assembly can reach this value as well.
– Attach warning signs for hot surfaces.
Caution - Damage to components!
If the valve is not checked and serviced at certain intervals, the function may be
overridden or significantly disturbed.
– It is recommended to carry out regular checks.
6.1 Valve actuator
• Safety relief valves protect a pressurised system against impermissible pressure
exceedance.
• Fluids (F), gases (G) and vapours (D) can be discharged via the safety relief valves.
• During normal operation the safety relief valve should not be activated / opened.
(Always ensure sufficient allowance between the operating pressure and the set
pressure).
• Safety relief valves open within an opening pressure difference of 10 % of the
response pressure. At a response pressure of < 1 bar, the opening pressure
difference can be up to 0.1 bar. The specified exhaust performance is achieved
here.
• The lifting itself can be performed according to the process requirements. The
duration of lifting should be about 5-20 seconds and can take place during different
cleaning steps. Lifting takes place during the startup phase of the pump with
reduced power.
6.2 Valve Tightness / Leak
If the area of the valve seat is not sealed properly (seal defective, foreign object trapped,
valve disk lifted manually, spring broken), the valve will exhaust in normal position (valve
closed).
This also results in pressure not being built up or only with difficulty in a pressurized
system.