Notes:
1. Expansion Valve and Temperature Pressure Relief Valve drain line diameter must
be no smaller than the nominal size of the valve outlet.
2. Drain line length must be in accordance with this table:
Maximum Relief Drain
Length (m)
Maximum Numbers of
Changes in Direction (greater
than 45°)
9
3
8
4
7
5
6
6
3. Drain line must discharge into a tundish when the distance to the final point of
discharge is greater than 9 m.
4. Drain Line must be of copper piping
5. If Expansion Valve and Temperature Pressure Relief Valve drain lines are to be
combined then refer to AS/NZ 3500.4:2015 Clause 5.11.3. Only one of each type to
be combined.
