Spirax-Sarco, a UK-based manufacturer of boiler and pipeline control valves for steam heating and process plants, has bought 30% of Econotherm for £1m ($1.5m).

It also has the option to acquire the remaining equity in the period between 1 January 2016 and 31 March 2019.

The transaction is expected to make a small positive contribution to group earnings from 2014, increasing each year thereafter.

Econotherm specialises in the design and manufacture of heat pipes and associated heat exchangers for industrial…