Relief valve – EVA 
A medium-controlled valve to put off load during the starting of rotary piston fans and single-stage screw-type compressors for unit output levels of up to160 m3/min-1
General characteristics
The start-up rotary piston fans and single-stage screw-type compressors with drive motors of 3 kW and more follows a Yi circuit. Backpressure must be avoided at all costs during start-up, i.e. during this phase the volume flow must be blown off. Up to now, sophisticated externally controlled fittings were used for this purpose.
Functional characteristics of the STRATE relief valve
The STRATE relief valve EVA is a medium-controlled, automatic, and maintenance-free and hence economical device to put off load during start-ups.
Function
If the fan aggregate is shut off, the valve is open. Once the fan unit is switched on, the generated air first is discharged through the blow-off slots (C) of the valve housing (1). By turning the adjustment ring (2) the cross-sections of the blow-off slots can be altered. A dynamic pressure develops inside the valve chamber (A). The blow-off opening is adjusted until the dynamic pressure is equal to 1/3 of the operating pressure. The dynamic pressure generates a load in the area above the diaphragm (B) pressing down the diaphragm (13) and closing the valve (3 and 6). The time required to fill the area above the diaphragm (B), and thus the valve’s reaction time, depends on the throttling action of the nozzle (9) and the dynamic pressure head. After setting the adjustment ring (2) to the correct dynamic pressure level, it is locked with the help of the adjusting screw (22). With this setting, the relief valve will operate automatically and maintenance-free also with all other aggregate settings.
Relief valve
–EVA–
Dimensions and technical data
|
TYPE |
10/S 10/E |
10/D 10/DE |
30/S 30/DE |
30/D 30/DE |
|
Max. output m3-/m |
10 |
10 |
30 |
30 |
|
Max. dynamic pressure mbar |
200 |
1500 |
200 |
1500 |
|
Max. operating pressure mbar |
1000 |
5000 |
1000 |
5000 |
|
Max. operating temperature °C |
130 |
250 |
130 |
250 |
|
Thread connection D |
R 2 ˝” |
R 2 ˝” |
R 4" |
R 4" |
|
Greatest diameter A mm |
155 |
150 |
280 |
280 |
|
Max. overall height B mm |
155 |
130 |
205 |
180 |
|
Solenoid valve C mm |
70 |
70 |
70 |
70 |
|
TYPE |
60/S 60/E |
60/D 60/DE |
150/S 150/E |
150/D 150/DE |
|
Max. output m3-/m |
60 |
60 |
160 |
160 |
|
Max. dynamic pressure mbar |
200 |
1500 |
200 |
1500 |
|
Max. operating pressure mbar |
1000 |
5000 |
1000 |
5000 |
|
Max. operating temperature °C |
130 |
250 |
130 |
250 |
|
Thread connection D |
DN 150 |
DN 150 |
DN 200 |
DN 200 |
|
Greatest diameter A mm |
280 |
280 |
390 |
390 |
|
Max. overall height B mm |
210 |
210 |
300 |
300 |
|
Solenoid valve C mm |
70 |
70 |
95 |
95 |
/S = Standard design
/D = for single-stage screw-type compressor
/E = with built-on solenoid valve
/DE = with built-on solenoid valve for single-stage screw-type compressors
TYPE 10 / TYPE 30 TYPE 60 / TYPE150