When a system has a long suction line riser, oil traps should be installed every how many feet of vertical rise?

In refrigeration systems, particularly when dealing with long suction line risers, it is crucial to manage the movement of oil within the system effectively. When refrigerant flows through the suction line, it can carry some oil with it, which is essential for lubricating the compressor. However, in vertical risers, gravity can cause oil to accumulate or get trapped, which may lead to oil starvation in the compressor and can adversely affect system performance.

Installing oil traps every 15 to 20 feet of vertical rise helps ensure that any oil that does settle in the line can be properly collected and returned to the compressor. This practice reduces the risk of oil becoming trapped and ensures a consistent supply of lubricating oil to the compressor, maintaining its efficiency and longevity.

If oil traps were installed too frequently, such as every 6 inches, it could create unnecessary points of resistance and potential clogging in the system, hindering refrigerant flow. Similarly, relying only on an oil trap at the top of the riser does not address oil accumulation that might occur lower down in the riser, increasing the risk of oil starvation for the compressor before the refrigerant reaches the top. Lastly, placing traps downstream of the accumulator could be too late, as any oil that