BREWER, Maine — The massive barge that took the first four locally built refinery modules to Texas for a $7 billion oil refinery expansion in that state has returned to Maine with parts for future modules.

The Columbia Boston barge, guided by tugboat Emma Foss, left Maine with the first load of 53 modules in late March and is expected back in Brewer just before 9 a.m. today.

Soon after its arrival, Cianbro employees will unload two pieces of equipment, called pressure vessels, that were transported from the Motiva Port Arthur Refinery by barge because they were too big to travel by road.

Pittsfield-based Cianbro Corp. was hired by Motiva Enterprises LLC to build 53 refinery modules, large heavy-duty steel structures filled with pipe and utilities. Cianbro set up its Eastern Manufacturing Facility along the Penobscot River in Brewer to build the modules. The company, which now employs around 400 skilled laborers in Brewer and another 70 or so at a pipe-making plant in Bangor, is expected to ship out the remaining 49 modules over the next 14 months.

The next shipment of modules bound for Texas is expected to leave Brewer in early June, Alan Grover, Cianbro spokesman, said Tuesday.

The Colombia Boston moored in Searsport just before 1 p.m. Tuesday and is scheduled to leave for its upriver trip at 5 a.m. today and arrive at the Cianbro bulkhead at 8:45 a.m., Grover said.