https://gallery.mailchimp.com/b47451119960b86956a72a02d/files/154d63e4-3996-4c02-84a7-c179c19aeec0/TECHNICAL_BULLETIN_33.pdfPowerex is saying their purge ports are too tight and cannot be removed with a crescent wrench. Must use a 9/32 square drive socket which all good plumbers should have with them. 

Well it's a $ 5.00 part on the www.

The right tool for the job.

Is that too much to ask?