- - 1.
Not be directly connected to the drainage system. (Jerry's note: Means that "it
may" be connected to the drainage system, just "not directly connected to" the
drainage system, it needs an air gap.)- - 2. Discharge through an
air gap located in the same room as the water heater. (Jerry's note: The
discharge pipe discharge through the air gap, and ends there at the air gap,
after the air gap is an indirect waste receptor, which has a drain line which,
if using an air gap, then drains to the outdoors.)
- - 3.
Not be smaller than the diameter of the outlet of the valve served and shall
discharge full size to the air gap. (Jerry's note: Obvious what that say, do not
reduce the valve outlet down to a smaller size.)
- - 4. Serve a single relief
device and shall not connect to piping serving any other relief device or
equipment. (Jerry's note: Shall serve only that one relief
valve.)
- - 5. Discharge to the floor, to an indirect waste receptor or to
the outdoors. Where discharging to the outdoors in areas subject to freezing,
discharge piping shall be first piped to an indirect waste receptor through an
air gap located in a conditioned area. (Jerry's note: The discharge pipe may
discharge to the floor, to an indirect waster receptor - 2. above -, or to the
outdoors - if the water heater is installed
outdoors.)
- - 6. Discharge in a manner that does not cause personal injury
or structural damage. (Jerry's note: Regardless where it discharges to, it is
not allowed to cause personal injury.)
- - 7. Discharge to a
termination point that is readily observable by the building occupants. (Jerry's
note: Means you are not allowed to hide it, which brings up the question: are
water heaters now allowed in closets where the discharge is not readily
observable by the occupants?)
- - 8. Not be trapped. (Jerry's note: That
one is obvious.)
- - 9. Be installed to flow by gravity.
(Jerry's note: If it is not trapped, then it must drain by gravity, which means
slope downhill.)
- - 10. Not terminate more than 6 inches
(152 mm) above the floor or waste receptor. (Jerry's note: The termination must
be within 6" of the floor or water receptor to control the discharge and help
prevent it from injuring the occupants.)
- - 11. Not have a threaded
connection at the end of the piping. (Jerry's note: So no valve, cap or other
device can easily be attached.)
- - 12. Not have valves or tee fittings.
(Jerry's note: Nothing to restrict or impede the
flow.)
- - 13. Be constructed of those materials listed in Section
P2904.5 or materials tested, rated and approved for such use in accordance with
ASME A112.4.1.