To give you an idea of its strength, Engineered Plastic is what they use to make artificial hearts. Besides choosing EP for the lower cost, you might want to consider EP fittings to go under concrete slabs in radiant heat applications. Concrete can sometimes eat away at metal if it's completely covered. Swapping the brass for EP will keep your fittings safe and sound.
ProPEX EP Elbows, ProPEX EP Couplings, ProPEX EP Tees and many other Wirsbo ProPEX fittings and valves can be found at www.supplyhouse.com
