Tom Eassie, chief executive, said success lay in the fact that markets for its valve actuator were spread across 50 countries. Exports account for 75 per cent of group turnover.
Key customers for the actuators, which open and close pipes to control the flow of solids, liquids and gases, include the water and oil industries. They total 80 per cent of group sales.
'Our markets, like water and power generation, are ones in which people cannot do without our products,' Mr Eassie said. 'If we have a problem in one place, we will be covered elsewhere. 'All we need is one good project, like a big refinery revamp or a huge sewage works. If you strike lucky a bad year becomes a good one.'
Sterling's depreciation helped to counter 'savage' pricing of actuators by international competitors.
Rotork made pre-tax profits of pounds 6.2m in the six months to June on turnover up 26 per cent at pounds 34m.
Acquisitions included the purchase of the actuation division's Venezuelan agent's business for dollars 700,000. Rotork Analysis, which analyses emissions from factories and refineries, bought a range of refinery analysers for pounds 1.15m.
Both deals were in May and made little contribution to the figures.
Rotork has a cash pile of pounds 13m after the acquisitions and after spending pounds 1.52m on the interim dividend, which was increased by 12.9 per cent to 1.75p. The shares rose 6p to 188p.