How to solve the problem of insufficient flow at the compressor inlet valve?
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The unit is equipped with two old nitrogen compressors, each with a capacity of 9000 Nm³/h. One of them has an inlet valve that is a DN250 gate valve; the pressure behind this valve can reach 12 kPa, allowing the compressor to operate at full load. The other compressor has an inlet valve that is a DN250 globe valve; the pressure behind this valve is -20 kPa, which prevents the compressor from operating at full load. Personally, I believe it is the difference in valve types that leads to variations in the coefficient of resistance. I plan to replace the globe valve with a gate valve, but changes need to be formalized. Do any of you have any relevant evidence or guidelines?
The pressure in the intake manifold is around 25 kPa. Can a DN250 globe valve meet the requirement of 9000 Nm³/h?
This post was last edited by CHANGBAISHI on 2019-7-20 08:28. The suction pressure of a compressor must be maintained at an appropriate level; the factors that cause a decrease in this suction pressure are usually a clogged pre-filter, a detached valve plate in the inlet valve, or too low pressure in the suction pipeline system. There are no other factors. As for whether the valve is suitable for this equipment, looking at the valve structure first, gate valves have the lowest resistance, while globe valves have the highest resistance. In operating conditions where the compressor inlet pressure is low, gate valves and butterfly valves with low resistance are generally used. One possibility is that it is caused by high valve resistance; another possibility is whether there is a problem with the arrangement of the inlet pipes for the two compressors. For reference. It is recommended to use a gate valve or butterfly valve with lower resistance. If it’s an old problem, then it’s related to the valves; if it’s a new issue, then check whether the valve heads have come loose. The filter must definitely be cleaned and inspected.