Hi.
I have a Frascold R-TSH8-60 screw compressor that, when the economiser is operating, has a pulsation in the economiser line. This pulsation varies with speed and gets that bad it has snapped the brass fitting in the economiser port. The system is running at -5oC/30oC on R404a. The only way to stop the pulsation is to shut off the economiser, or overfeed the economiser so it floods back. I have tried a muffler, reducing the economiser suction line, and both. Has anyone else had these issues, or know of a way to reduce the pulsations?