5
Top of Boiler Showing Factory fitted Valves
The discharge pipe work from the tundish, shall fall continuously throughout its length. Pipe runs must
not exceed 9m in length or equivalent resistance with bends. A 15mm pipe from the tundish is made
available for connection to the C/H pressure relief valve (see page 7).A full description regarding the
regulations for installing the tundish is provided on page 6.
Draining System
The boiler can be drained by the valve at the bottom of the tank, a sink hot tap should be
opened to allow air into the system.
WARNING
The outlets for the T&P relief valve and expansion relief valve must not be used for any other purpose. No
other valve may be fitted between the expansion valve or the temperature and pressure relief valve and the
storage boiler.
Take great care not to allow debris or jointing tape to get into the system as this could impair the operation
of the safety valves.
Tundish worked example
The example below is for a G1/2 temperature relief valve with a discharge pipe (D2) having 4No
elbows and a length of 7m from the tundish to the point of discharge
Tundish
Special attention must be paid to the Tundish to comply with G3 regulations, a copy of which
is shown below.
Sizing of copper discharge pipe for common temperature relief valve outlet sizes table 1
