Exhibit 21
Pentair plc and subsidiaries as of December 31, 2018
| Name of Company | Jurisdiction of Incorporation | |
| Aplex Industries, Inc. | United States | |
| Century Mfg. Co. | United States | |
Chansuba Pumps Private Limited (1) | India | |
| Edward Barber & Company Limited | United Kingdom | |
| Edward Barber (U.K.) Limited | United Kingdom | |
| Epps, Ltd. | Mauritius | |
| ETE Coliban Pty Limited | Australia | |
| Everpure Japan Kabushiki Kaisha | Japan | |
FARADYNE Motors (Suzhou) Co., Ltd (2) | China | |
Faradyne Motors LLC (2) | United States | |
| FilterSoft, LLC | United States | |
| Fleck Controls, Inc. | United States | |
| Goyen Controls Co. Pty. Limited | Australia | |
| Goyen Valve LLC | United States | |
| Great American Aquaculture, LLC | United States | |
| Greenspan Environmental Technology Pty Ltd | Australia | |
| Haffmans B.V. | Netherlands | |
| Haffmans North America, Inc. | United States | |
| Hawley Group Canada Limited | Canada | |
| Holding Nijhuis Pompen B.V. | Netherlands | |
| Hypro EU Limited | United Kingdom | |
Infinite Water Solutions Private Limited (2) | India | |
| Jung Pumpen GmbH | Germany | |
| Lincoln Automotive Company | United States | |
| McNeil (Ohio) Corporation | United States | |
| MECAIR S.r.L. | Italy | |
| Milperra Developments Pty Limited | Australia | |
| Moraine Properties, LLC | United States | |
Nano Terra, Inc. (3) | United States | |
| Nijhuis International B.V. | Netherlands | |
| Nijhuis Pompen B.V. | Netherlands | |
| Nijhuis Pompen BVBA | Belgium | |
| Nijhuis Pompen Exploitatiemaatschappij B.V. | Netherlands | |
| Panthro Acquisition Co. | United States | |
| Pentair (NZ) Limited | New Zealand | |
| Pentair Aquatic Eco-Systems (Canada), Inc. | Canada | |
| Pentair Aquatic Eco-Systems, Inc. | United States | |
| Pentair Australia Holdings Pty Limited | Australia | |
| Pentair Beteiligungs GmbH | Germany | |
| Pentair Canada, Inc. | Canada | |
| Pentair Chile SpA | Chile | |
| Pentair Clean Process Technologies India Private Limited | India | |
| Pentair Denmark Holding ApS | Denmark | |
| Pentair Environmental Systems Limited | United Kingdom | |
| Pentair Epsilon Limited | Bermuda | |
| Pentair Federal Pump, LLC | United States | |
| Pentair Filtration Solutions, LLC | United States | |
| Pentair Finance Group GmbH | Switzerland | |
| Pentair Finance Holding GmbH | Switzerland | |
| Pentair Finance S.a.r.l. | Luxembourg | |
| Pentair Flow Control International Pty Limited | Australia | |
| Pentair Flow FZE | United Arab Emirates | |
| Pentair Flow Services AG | Switzerland | |
| Pentair Flow Technologies de Mexico, S. de R.L. de C.V. | Mexico | |
| Pentair Flow Technologies Pacific Pty Ltd | Australia | |
| Pentair Flow Technologies, LLC | United States | |
| Pentair France SARL | France | |
| Pentair Germany GmbH | Germany | |
| Pentair Global Holdings B.V. | Netherlands | |
| Pentair Global S.a.r.l. | Luxembourg | |
Pentair Group (Thailand) Limited (4) | Thailand | |
| Pentair Holdings S.a.r.l. | Luxembourg | |
| Pentair Holdings, Inc. | United States | |
| Pentair Housing, Inc. | United States | |
| Pentair Housing, LP | United States | |
| Pentair Iceland Holdings ehf | Iceland | |
| Pentair International (UK) Ltd | United Kingdom | |
| Pentair International Holding S.a.r.l. | Luxembourg | |
| Pentair International Sarl | Switzerland | |
| Pentair Investments Switzerland GmbH | Switzerland | |
| Pentair Ireland Limited | Ireland | |
| Pentair Janus Holding LLC | United States | |
| Pentair Janus Holdings | Bermuda | |
| Pentair Kenya Limited | Kenya | |
| Pentair Luxembourg S.a.r.l. | Luxembourg | |
| Pentair Management Company | United States | |
| Pentair Manufacturing Belgium BVBA | Belgium | |
| Pentair Manufacturing France S.A.S. | France | |
| Pentair Manufacturing Italy S.r.L. | Italy | |
| Pentair Middle East FZE | United Arab Emirates | |
| Pentair Nanosoft US Holdings, LLC | United States | |
| Pentair Netherlands Finance B.V. | Netherlands | |
| Pentair Netherlands Holding B.V. | Netherlands | |
| Pentair Pacific Rim (Water) Limited | Hong Kong | |
| Pentair Pacific Rim, Limited | Hong Kong | |
Pentair Philippines, Inc. (4) | Philippines | |
| Pentair Residential Filtration, LLC | United States | |
| Pentair Services France S.A.S. | France | |
| Pentair Shenzhen Enclosure Company, Ltd. | China | |
| Pentair Sudmo GmbH | Germany | |
Pentair Tamimi LLC (5) | Saudi Arabia | |
Pentair Technical Services L.L.C. (6) | United Arab Emirates | |
| Pentair Trading (Shanghai) Co., Ltd. | China | |
| Pentair Transport, Inc. | United States | |
| Pentair Tubing Limited | United Kingdom | |
| Pentair UK Group Limited | United Kingdom | |
| Pentair UK Holdings Limited | United Kingdom | |
| Pentair Valves & Controls del Uruguay S.A. | Uruguay | |
| Pentair Water (Suzhou) Company, Ltd. | China | |
| Pentair Water Asia Pacific Pte. Ltd. | Singapore | |
| Pentair Water Australia Pty Ltd | Australia | |
| Pentair Water Belgium BVBA | Belgium | |
| Pentair Water Brazil LLC | United States | |
| Pentair Water do Brasil Ltda. | Brazil | |
| Pentair Water France SAS | France | |
| Pentair Water Group, Inc. | United States | |
| Pentair Water Holdings, LLC | United States | |
| Pentair Water India Private Limited | India | |
| Pentair Water Italy S.r.l. | Italy | |
| Pentair Water Latinamerica S.A. | Argentina | |
| Pentair Water Operations Australia Pty Ltd | Australia | |
| Pentair Water Polska Sp.zoo | Poland | |
| Pentair Water Pool and Spa, Inc. | United States | |
| Pentair Water Proces Technologie Holding B.V. | Netherlands | |
| Pentair Water Process Technology B.V. | Netherlands | |
| Pentair Water Purification Systems (Shanghai) Co., Ltd. | China | |
| Pentair Water Spain, S.L. | Spain | |
| Pentair Water Treatment (OH) Company | United States | |
| Pentair Water Treatment Company | United States | |
Pentair Water Treatment Private Limited (7) | India | |
| Pentair Water, LLC | United States | |
| Pentair Water-Mexico, S. de R.L. de C.V. | Mexico | |
| Pentair, Inc. | United States | |
| Penwald Insurance Company | United States | |
| Peocon ehf. | Iceland | |
| PES Pty Ltd | Australia | |
| PFAM, Inc. | United States | |
| Plymouth Products, Inc. | United States | |
| PTG Accessories Corp. | United States | |
| Seneca Enterprises Co. | United States | |
| Sta-Rite de Mexico, S.A. de C.V. | Mexico | |
| Sta-Rite de Puerto Rico, Inc. | Puerto Rico | |
| Sta-Rite Industries, LLC | United States | |
| Sudmo (UK) Ltd. | United Kingdom | |
Surface Logix LLC (8) | United States | |
| Tupelo Real Estate, LLC | United States | |
| Union Engineering (NingBo) Co., Ltd. | China | |
| Union Engineering A/S | Denmark | |
| Union Engineering Holding II A/S | Denmark | |
| Union Engineering Holding LLC | United States | |
Union Engineering Latam Ltda (9) | Brazil | |
| Union Engineering North America LLC | United States | |
| Urban Organics Pentair Group, LLC | United States | |
| Urban Organics Schmidt Real Estate Group, LLC | United States | |
| Urban Organics St. Paul, LLC | United States | |
| Vaki A/S | Norway | |
| Vaki Aquaculture Systems ehf. | Iceland | |
| Vaki Chile Ltda | Chile | |
| Vaki Scotland Ltd | United Kingdom | |
Voltea Ltd. (10) | United Kingdom | |
| Webster Electric Company, LLC | United States | |
| Wicor Industries (Australia) Pty. Ltd. | Australia | |
| X-Flow B.V. | Netherlands | |
(1) | 47% owned |
(2) | 50% owned |
(3) | 4.81% owned |
(4) | 99.99% owned |
(5) | 70% owned |
(6) | 49% owned |
(7) | 74% owned |
(8) | 0.03% owned |
(9) | 99% owned |
(10) | 1.69% owned |