Filtration and environmental technologies group Porvair said it expects to report full-year results ahead of expectations. Revenue for the year through November, at constant exchange rates, is 10% higher than the prior year, according to a trading update on Wednesday.The Microfiltration division has achieved a 16% rise in revenue, driven by significant activity from contracts with steel making company POSCO, Indian conglomerate Reliance Industries and the UK government. The Seal Analytical division, a manufacturer of water quality analysis equipment for environmental and industrial laboratories, has also traded well. Thomas Cain, which was acquired in September 2013, is trading as expected and has made a positive contribution to Seal's performance.Trading in the Metals Filtration division improved in the second half, after a quieter first half, and revenues for the full year are in line with last year.A new plant in Xiaogan, China, has been completed on time and budget and production from the plant has begun. Porvair has spent £3m on acquisitions in the year but strong operating cash flows have reduced net borrowings in the year by £4m to leave the group with a small net cash surplus. Shares were up 2.80% to 292.72p at 09:30 on Wednesday. RD