Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Applications:<br />
• Large steam boilers in power stations<br />
• Industrial heating boilers:<br />
– High system availability and greatest<br />
possible use of the maximum allowable<br />
working pressure<br />
– Paper mills<br />
– Chemical industry<br />
– Sugar factories<br />
LESER safety valves can be equipped with a supplementary loading<br />
system. <strong>The</strong> supplementary loading system consists of four components:<br />
• <strong>Safety</strong> valve<br />
• Actuator<br />
• Control units (pneumatic, electric/pneumatic)<br />
• <strong>Valve</strong> lift actuator<br />
<strong>The</strong> supplementary loading system (ZB) allows the system operating<br />
pressure to be increased (∆p+) to just below the set pressure of the<br />
safety valve (SV). <strong>The</strong> functional leak tightness of the additionally loaded<br />
safety valve is ensured up to the set pressure (anti-simmer device). When<br />
the safety valve operates the supplementary loading device assists the<br />
opening [2] and closing [1] processes, thus returning the system to its<br />
original service condition more rapidly. As a result the blow-off process is<br />
shortened and the product losses are smaller.<br />
pressure p<br />
Set pressure<br />
Operating pressure ZB<br />
Operating pressure SV<br />
∆ p+<br />
1 2 1<br />
Blow-down ZB<br />
Blow-down SV<br />
t failure ZB<br />
t failure SV<br />
time t<br />
1 2<br />
loaded<br />
open<br />
33
Change language