Provision for Refrigerant Removal

This is an update to a blog that was originally posted on 8/4/15. You can read the original blog here.

Most people who have worked around the ammonia refrigeration industry for any period of time recognize the importance that strainers play in the proper operation and maintenance of an ammonia refrigeration system. Typically located upstream of control valves, strainers perform the important function of filtering out debris that would otherwise damage control valves and prove detrimental to system operation. Strainers require periodic cleaning to remove debris that has been collected, but unfortunately, an all too common deficiency that I see at facilities is that no provision is made available to safely remove ammonia from the strainer, as is necessary to safely facilitate maintenance.  An often overlooked requirement of ANSI/IIAR 2-2021 requires that “Valve groups shall be fitted with a provision for ammonia removal to facilitate maintenance of strainers.” (§13.3.2.4). Ignoring this simple requirement increases the risk associated with performing the routine tasks of cleaning a strainer and maintaining control valves.