Valve surge problem
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Our company has a steam boiler with a capacity of 80 t/h at full load; it generates steam at a pressure of 40 bar. The pressure in the steam drum is around 2 bar, which corresponds to the pressure difference specified on the official specifications. The steam grid-connected control valve is a ball valve. When the steam production is above 60 tons and the opening degree of the grid connection valve is at 100%, severe surge occurs; reducing the valve’s opening degree to 85–90% by switching it to manual mode resolves the issue. May I ask the experts here: what is the cause of this surge, and what are the possible solutions? Thank you
Is the ball valve stem moving up and down? Are you sure it’s a ball valve?
Three eccentric ball valves, from Orbitek, maybe.
It was caused by improper grid connection procedures. During grid connection, the grid connection valve cannot be opened fully (whether manually or automatically); it should be opened gradually to ensure a smooth grid connection. Otherwise, an excessive amount of air in the system can cause a \"air hammer\" effect in the piping network
I can’t understand what it means for the stem of a ball valve to move up and down. . . Am I ignorant? A ball valve isn’t it a rotary-type valve? How can there be movement up and down?
Under specific operating conditions, when the vibration frequency generated by fluid flow matches the valve’s natural frequency, this is what is known as resonance. Experience shows that by appropriately adjusting the opening degree of the valves located before and after the control valve (there are usually such valves in front of and behind a control valve), it is possible to change the opening degree of the control valve itself, thereby altering the speed at which fluid flows through the valve and thus changing the vibration frequency
What was said upstairs is correct; by carrying out actual operations and adjusting the sizes of the front and rear shut-off valves appropriately, the issue mentioned by the original poster can be resolved