MrPEX Systems

The MrPEX PEX-a system: 136 F1960 cold expansion fittings, 51 radiant manifolds, 55 tubing coils and 18 F2159 press fittings, plus expansion tools and controls. 289 items in all.

F1960 is a cold expansion joint and it only works on PEX-a. The tool stretches the tube and the ring together, then the tube's thermal memory pulls it back down onto the fitting barb over the next few minutes. PEX-b and PEX-c do not recover fast enough or far enough to make that joint, which is why an expansion tool and an F1960 fitting are not a general PEX solution — they are a PEX-a solution. F1807 crimp and F2159 press rings work across PEX types; F1960 does not.

Barrier or non-barrier is the other decision that cannot be undone later. An oxygen barrier tube is required on any closed hydronic loop that contains ferrous components: a cast iron boiler section, a steel expansion tank, a cast iron circulator volute. Without the barrier, oxygen diffuses through the tube wall continuously and corrodes those parts from the inside. On potable water there is no ferrous loop to protect and non-barrier is the correct tube. We stock 21 barrier and 32 non-barrier coils.

Tubing colors are red (30), white (14), blue (9). The color carries no rating; it is a field convention for keeping supply, return and potable runs apart.

Manifolds run 2 to 12 branches on a 1-1/4" trunk. Size the trunk to the total loop flow, not to the branch count.

Dimensions per ASTM F876, pressure and temperature ratings, bend radius and fitting compatibility are collected in our PEX tubing reference.