Polaris Genuine OEM 1/8″ NPTM Plastic Plug

The Polaris P20 is a plastic plug with a 1/8 inch male pipe thread, shown in the parts diagram for the PB4-60 booster pump. It is the genuine Polaris OEM part.

What it does

Pump housings are molded with more ports than any single installation uses, so that the same casting can serve a gauge here, a drain there, or nothing at all. A plug closes the ports that are not in use. This one is the small 1/8 inch size, and it is molded in plastic to match the housing it threads into.

Fitting it

Wrap the thread with PTFE tape or use a thread sealant suited to plastic, then run it in hand tight and give it only a small nudge beyond that. Pipe threads are tapered and seal by wedging, so extra force does not buy a better seal. It drives the plug deeper into the port and is a common way of cracking a housing that was perfectly sound before the repair.