The Glasgow company designed, installed and built the training pools for the Olympics and Paralympics and has more recently been involved in dismantling them.
The pool structures are now in storage and will be rebuilt in towns around the UK as part of the Olympic legacy programme.
Accounts for the 12 months to September 30, 2012, being filed at Companies House will show Barr + Wray's operating profits rising from £1.04m to £1.32m.
Chief executive Alister MacDonald, speaking from Lake Garda in Italy where he was visiting a supplier, said: "The biggest thing for us during the year was our part in the London Olympics.
"A lot of the equipment was built off-site then dropped into the Olympic Park in February 2012.
"We commissioned it in April and May time then the pools were used during the Olympics and Paralympics.
"We then began dismantling them in October. They are now being stored off-site and will be built in permanent locations around the UK as part of the legacy."
Mr MacDonald said the business expected to see much of its growth in the coming years from its international operations in Dubai and Hong Kong.
Yet Barr + Wray recently won its largest ever single contract, worth more than £4m, from holiday village operator Center Parcs to fit out the pools and spas at its new resort at Woburn Forest in Bedfordshire.
The Scottish business will provide filtration, water treatment and pumping equipment for seven pools at the site plus pipes and controls for flumes, play structures and water features.
Last year Barr + Wray secured a £700,000 refurbishment contract for the swimming pool at the Center Parcs in Elveden Forest.
Mr MacDonald said: "The order book is looking good [for 2013] with Center Parcs and with our new overseas business.
"Our overseas business is already contributing around 35% to our group turnover, but it has been pleasing to continue to do so well in our domestic markets. Conditions are still challenging, but it is encouraging to see our UK business enjoying double digit [percentage] growth."
Barr + Wray has also built a hydrotherapy suite and vitality pool at the Emirates Arena in Glasgow, which will be used during the 2014 Commonwealth Games.
Its UK offices, which employ 100 people, continue to win and deliver international projects such as the £1.8m spa and pool for ESPA at Resorts World Sentosa on the southern coast of Singapore.
The business was set up in 1959 as a distributor of pump and filter products but has reinvented itself as a supplier, designer and installer of spas, swimming pools and water treatment services.
Its spas are installed in more than 25 countries with clients including hotel groups such as Mandarin Oriental, Four Season and Jumeriah.
In the UK market its process equipment and pools are used by customers including Highland Spring, National Semiconductor, Diageo and the Ministry of Defence.