Welcome to the forum. Although you can post in any forum, the USA forum is here in case of local regs or laws
Thank you that was very helpful, I managed to find a Plassons coupler locallyOops, both links the same. Here's the Philmac home page....https://www.philmacinc.com/
Reply to the thread, titled "What type of connection is this?" which is posted in UK Plumbers Forums on Plumbers Forums.
We recommend City Plumbing Supplies, BES, and Plumbing Superstore for all plumbing supplies.