AquaMAX EM50 Series - Manual (Page 22)

21
Pressure Temperature Relief Valve (PTR valve)
The PTR valve must be fitted before the water heater is operated. Before
fitting the PTR valve, make sure the valve probe has not been bent. Seal
the valve thread with thread sealing tape (never use hemp) and ensure the
tape does protrude past the end of the thread.
For E400 ~ E80 models; screw the PTR valve clockwise into the right hand
side opening on the water heater marked “PTR” (refer to E400 ~ E80
Models diagram on page 29) with the valve outlet pointing downwards.
For EM50 models; screw the PTR valve clockwise into either opening on
the water heater marked “PTR” (refer to EM50 model diagram on page 30)
with the valve outlet pointing downwards.
Do not use a wrench on the valve body – use a spanner on the spanner
flats. A copper drain line must be fitted to the PTR valve (refer to “Relief
Valve Drain(s)” on page 21).
Relief Valve Drain(s)
DN15 copper drain lines must be fitted to the ECV and PTR valve (if one is
installed) to carry the discharge clear of the water heater. Connect the drain
lines to the valves using disconnection unions. The drain line from the valve
to the point of discharge should be as short as possible, have a continuous
fall all the way from the water heater to the discharge outlet and have no
tap, valves or other restrictions in the pipe work. A drain line from a relief
valve must comply with the requirements of AS/NZS 3500.4.
A drain line must be no longer than 9 metres with no more than three
bends greater than 45° before discharging at an outlet or air break. The
maximum length of 9 metres for a drain line is reduced by 1 metre for each
additional bend required of greater than 45°, up to a maximum of three
additional bends. Where the distance to the point of final discharge
exceeds this length, the drain line can discharge into a tundish.
Subject to local regulatory authority approval, the drain lines from the ECV
and PTR valve from an individual water heater may be interconnected.
The outlet of a drain line must be in such a position that flow out of the pipe
can be easily seen, but arranged so discharge will not cause injury,
damage or nuisance. The termination point of a drain line must comply with
the requirements of AS/NZS 3500.4. Drain lines must not discharge into a
safe tray.
In locations where water pipes are prone to freezing, drain lines must be
insulated, must not exceed 300mm in length and are to discharge into a
tundish through an air gap of between 75mm and 150mm.