Summarized Financial Information of Reportable Segments (Detail) (USD $)
 3 Months Ended 6 Months Ended
Jun. 30, 2012
Jun. 30, 2011
Jun. 30, 2012
Jun. 30, 2011
Dec. 31, 2011
Operating revenues, net:          
- Products $ 2,594,974 $ 4,103,236 $ 3,234,736 $ 5,254,668  
- Services 707,650 783,160 1,266,259 2,247,129  
Total operating revenues 3,302,624 4,886,396 4,500,995 7,501,797  
Cost of revenues 2,792,866 3,763,915 3,570,706 5,579,834  
Gross profit 509,758 1,122,481 930,289 1,921,963  
Depreciation and amortization 212,238 145,736 382,036 289,976  
Total assets 43,899,083 37,094,694 43,899,083 37,094,694 43,817,923
Expenditure for long-lived assets 467,837 2,373,158 473,910 2,566,246  
Valves Manufacturing Business
          
Operating revenues, net:          
- Products 2,594,974 4,103,236 3,234,736 5,254,668  
- Services 707,650 783,160 1,266,259 2,247,129  
Total operating revenues 3,302,624 4,886,396 4,500,995 7,501,797  
Cost of revenues 2,792,866 3,763,915 3,570,706 5,579,834  
Gross profit 509,758 1,122,481 930,289 1,921,963  
Depreciation and amortization 212,238 145,736 382,036 289,976  
Total assets 43,899,083 37,094,694 43,899,083 37,094,694  
Expenditure for long-lived assets $ 467,837 $ 2,373,158 $ 473,910 $ 2,566,246