Tundish installation and discharge requirements

Each temperature relief valve and expansion valve should discharge through a metal pipe either individually, or via a manifold, to a tundish incorporating an air break. Where the discharge is individual, the pipe size between the valve and the tundish, should be not less than the nominal outlet size of the valve. Where a manifold is used it should be so sized that it can accept the total discharges from the valves connected to it. Where discharges from safety devices may not be apparent (i.e. in dwellings occupied by people with impaired vision or mobility), consideration should be given to the installation of a suitable safety device to warn when discharge takes place (e.g. electronically operated). The tundish should be located – (a) vertically; (b) not more than 500 mm horizontally from any valve discharging to it; (c) where it can be readily seen but not create a hazard; and (d) in the case of a temperature relief valve – in the same space as the storage vessel. The tundish should be connected to a discharge pipe complying with paragraphs 2.14 to 2.17.