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About DMN


DMN Machinefabriek Noordwykerhout were established in 1950 as a subsidiary of Verschure & Co., a shipbuilding company in Amsterdam, Holland. In 1969 DMN were taken over by IHC Holland NV, a company specialised in the building of ships for dredging. In 1971 DMN obtained a license from Westinghouse Systems (U.K.) for the manufacture and marketing of bulk solids handling components in Europe. IHC Holland NV decided in 1989 to concentrate on its core business and sell DMN. DMN then became an independent company, fully able to determine its own destiny.

In 1990 the management decided to concentrate on solids handling equipment as the company’s core business. In 1998 DMN bought the business from Westinghouse Systems, and became the owner of the products and brand name. Since then the variety of rotary valves has been extended and DMN have also developed a comprehensive line of diverter valves, all under the brand name DMN-WESTINGHOUSE.

At present DMN are an international company with five sales offices and 2 production facilities, employing 140 people worldwide.


DMN are an independent Dutch company with no affiliation whatsoever to any systems company. DMN offer tailor made solutions for chemical, food, plastics, pharmaceutical and cement industries. Our core business is the design and manufacture of components, not systems. DMN abide by this strategy, as we do not want to become a competitor of our major customers, such as the system integrators.


DMN design and manufacture rotary valves and diverter valves for the bulk solids handling industry. The rotary valves include airlocks, blow through airlocks, sanitary and dairy airlocks (optionally with slide bars), medium duty airlocks, dust locks and granular rotary valves. The inlet sizes vary from 80 to 500 mm with capacities from 0,02 ltr/rev to 230 ltr/rev.

To meet specific requirements, the valves can be supplied in a wide range of materials, such as cast iron, aluminium or stainless steel. If necessary the valves can be provided with a special coating, such as hard chromium, tungsten carbide, Teflon, nickel or ceramic.

The rotor and rotor blades are also available in an array of designs. The extensive line of diverter valves enables the customer to divert or convert product by means of a flap, ball, tube or plug type diverter. The DMN diverter range also includes multi-port diverters, gravity plug diverters and fill vent valves. The diverter valves can be supplied in sizes varying from 38 to 300 mm line sizes, depending on type and model.

Besides these valves, DMN also supply complementary components, such as the original Morris pipe couplings, slide valves and pressure relief valves.


In 1992 DMN were awarded an ISO 9002 certificate. Since 1995 DMN have been ISO 9001 approved for the development, manufacturing and sales of components used in pneumatic conveying systems for bulk solids handling.

Several DMN components have been accepted by the USDA (United States Department of Agriculture) for use in dairy applications, and/or approved by DMT (Deutsche Montan Technologie) for explosion resistance up to 10 bar and flameproofness in the event of a class I dust explosion. Also most DMN components have been approved according to ATEX Directive 94/9/EC.


DMN-WESTINGHOUSE products are distributed worldwide. The past decade DMN have been continuously expanding, resulting in its own sales offices in the Netherlands (head office), France, Germany, the UK and USA.

DMN also have long-established relations with distributors in Italy, Singapore, Australia and New Zealand, Scandinavia, Spain, Greece, PR China and South Korea. Recently DMN have appointed representatives in Turkey and Central & South America. This extensive network of subsidiaries, distributors and representatives ensures a high level of service and support all over the world.


DMN have two production facilities, one in Noordwijkerhout, the Netherlands, and one in Altshausen, Germany. These very modern production facilities enable us to guarantee a constant high quality, maintain an efficient stock level and ensure short delivery times. The factory in the Netherlands is specialised in the manufacture of rotary valves, the factory in Germany is specialised in the manufacture of diverter valves.

Research and Development

All rotary valves and diverter valves in the DMN-WESTINGHOUSE product range have been developed in-house. The development of new products often takes place together with major customers. Of course all components are continuously under review with regard to value engineering and functionality.

Service and support

Most DMN offices offer maintenance and repair services. Depending on the situation these services take place either at the customer’s premises or at the DMN office. DMN can supply all standard wear parts from stock, thus reducing downtime due to maintenance or valve failure.


The multilingual DMN website includes an overview of our products, contact addresses of our sales offices and exhibitions. The site also includes the latest news regarding our company and our products, as well as the possibility to contact one of our sales offices directly.