Anti-surge
Bypass Valves for Reliable Compressor Protection
Application Overview
Compressor anti-surge protection is vital for all centrifugal and axial compressors. Compressor surge occurs when the downstream process flow demand quickly decreases (such as in an emergency shut-down), causing a rapid increase in downstream pressure and changing the compressor's operating point.
If the compressor is no longer able to maintain the necessary pressure ratio, this will result in a change in flow direction. This momentary pressure ratio collapse will cause yet another change in flow direction. As long as the root cause is not eliminated, this cyclical behavior will persist, known as compressor surge. This will result in severe vibration and rapid temperature increase, which can ultimately cause major or catastrophic damage to the compressor.
Anti-Surge Valves at a Glance
| 3591 - HEAVY DUTY CAGE VALVE | |
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Size: 16" to 32" ANSI Class: 150 to 900 Std. Materials: Carbon Steel, Stainless Steel Temperature Range: -50 to 932oF (-46 to 500oC) Special Features
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| LTR 43 - TRIPLE OFFSET BUTTERFLY VALVE | |
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Size: 3" to 80" ANSI Class: 150 to 2500 Std. Materials: Carbon Steel, Stainless Steel Temperature Range: -325 to 1832oF (-196 to 1000oC) Special Features
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SAMSON Solutions
Anti-surge protection is provided by a control valve which will either exhaust the gas or vapor from the compressor into the atmosphere, or recirculate it back to the compressor inlet. A reliable control valve that functions consistently under the most severe conditions is absolutely essential to the protection of the compressor. Some of the main challenges faced in anti-surge applications are:
Fast Acting
To prevent surge conditions, control valves will generally be required to fully open in ½ to 2 seconds. SAMSON offers a wide variety of control valve accessories to meet the most stringent actuation time requirements, even on large valves sizes.
High Valve Noise
The extreme flow conditions can often cause the control valve to become very noisy if special design consideration aren't given to attenuation. SAMSON offers many different trim technologies and downstream equipment designed to reduce the noise generated by the valve.
Severe Vibration
As a result of the extreme flow conditions and high noise level, areas around the anti-surge control valve may also experience high vibration. SAMSON offers several valve configurations designed specifically to stand up to high vibration applications.
Tight Shut-off
The anti-surge valve shut-off directly affects the efficiency of the system. SAMSON offers optional high performance metal sealing to achieve leakage class V requirements and soft sealing options achieving leakage class VI.