Valves around the world

RIS Rubber makes many different rubber seals for Emerson’s Keystone valve products.

The collaboration started with a small number of product groups that have expanded over time to a whole range of seals. In addition to the amount of products, the cooperation with the companies within the Emerson group has also increased. RIS Rubber transports shipments all over the world from Lelystad to Emerson locations every week. They have 200 locations worldwide. Hofland (our branch in Tolbert) is now also producing for Emerson by cutting various packings (sheet material).

From big to small

The many rubber seals we produce are made in many different sizes and types of rubber. The smallest seal RIS Rubber makes is Ø25mm and the largest is Ø1200mm. We produce the smaller seals on our injection presses because this is fast and efficient production. The purchase volume here is also often large, which is why this production method is extremely suitable for this. If the products become larger, we switch to our compression presses, where we have more space and can therefore work with larger moulds.

Various applications

Because Keystone valves are widely used in various application areas, we also produce the seals in many different compounds. Many seals are made in EPDM, NBR and FKM, in which we also have different recipes for each type of rubber, such as white NBR or an EPDM with approval. Because of these different types of rubber, we have separate molds for some rubber types per diameter to compensate for the shrinkage difference of the rubber. The seals are very critical and must have the correct dimensions. If this is not in accordance with the specification, the valve can leak or close very difficult because there is too much resistance. RIS and Emerson engineering teams have collaborated on compound formulation to develop seals that support market leading sealing and cycle-life. We therefore make a specific product in the right rubber type and quality for every field of application.


In addition to full rubber seals, we also produce seals with metal reinforcements for vacuum applications. We also rubberize large metal bodies from Ø40mm to Ø1200mm, which are mainly used for the drainage and supply of water to large construction projects. These metal bodies sometimes weigh up to 750 kilos in total and are in the press for up to 6 hours to be rubberized.

The wide range of products that Emerson can supply also requires a wide range of machinery with different techniques from RIS Rubber. Because our colleagues at Hofland Rubber have CNC-controlled cutting tables, we can also supply gaskets and serve the customer even better.