As the old saying goes, an ounce of prevention is worth a pound of cure. This is especially true when a replacing a thermostatic expansion valve (TXV).
Even though the circulated refrigerant is the working fluid required for cooling, lubricant or oil is needed for lubrication of the compressor’s moving mechanical parts.
Before servicing any refrigeration or air conditioning systems that contain an oil pump, technicians should make sure they understand the difference between net oil pressure and oil pump discharge pressure.