Exhibit 21.1

List of Material Subsidiaries



|                                                     |  |              |  |                              
|---------------------------------------------------- |  | ------------ |  | -----------------------------
|Subsidiary                                           |  | % Ownership1 |  | Jurisdiction of Incorporation
|Axsia Group Limited                                  |  | 100%         |  | UK                           
|Axsia Holdings Limited                               |  | 100%         |  | UK                           
|Axsia Howmar Limited                                 |  | 100%         |  | UK                           
|Axsia Limited                                        |  | 100%         |  | UK                           
|Fluid Processing (Labuan) BHD                        |  | 100%         |  | Malaysia                     
|Linco-Electromatic, Inc.                             |  | 100%         |  | Texas                        
|NATCO Canada, Limited                                |  | 100%         |  | Alberta, Canada              
|NATCO Group de Venezuela, S.A.                       |  | 100%         |  | Venezuela                    
|NATCO Japan Company, Limited                         |  | 60%          |  | Japan                        
|NATCO Luxembourg S.a.r.l.                            |  | 100%         |  | Luxembourg                   
|NATCO Norge Holdings AS                              |  | 100%         |  | Norway                       
|NATCO Norway AS                                      |  | 100%         |  | Norway                       
|NATCO UK Limited                                     |  | 100%         |  | UK                           
|National Tank Company                                |  | 100%         |  | Delaware                     
|NTC Technical Services SDN BHD                       |  | 100%         |  | Malaysia                     
|NTC Technical Services, Inc.                         |  | 100%         |  | Delaware                     
|NTG Group de Mexico, S. de R.L. de C.V.              |  | 100%         |  | Mexico                       
|Richard Mozley Limited                               |  | 100%         |  | UK                           
|Scomi-NTC Sdn Bhd                                    |  | 30%          |  | Malaysia                     
|SureFire Pilotless Burner Systems LLC                |  | 50%          |  | Delaware                     
|TEST Angola Tecnologia e Serviços Petrolíferos, Lda. |  | 49%          |  | Angola                       
|TEST Automation & Controls, Inc.                     |  | 100%         |  | Louisiana                    
|TEST International                                   |  | 100%         |  | Cayman Islands               
|TEST Nigeria, Limited                                |  | 100%         |  | Nigeria                      
|Total Engineering Services Team, Inc.                |  | 100%         |  | Louisiana                    
|Western Measurement Equipment Co.                    |  | 100%         |  | Colorado                     
|Connor Sales Company                                 |  | 100%         |  | North Dakota                 
|Process Analytical Applications, Inc.                |  | 100%         |  | Texas                        
|Natco Al-Rushaid Middle East Limited                 |  | 50%          |  | Saudi Arabia                 





|1 | Represents ownership on a consolidated basis
|- | --------------------------------------------