Pumps und Valves for SCR-Systems

Our robust products for the type of SCR systems used in exhaust gas treatment are based on many years of experience in the development of valves and pumps. The special features of our pumps and valves enable simplified systems and enhanced durability. Our pumps and valves for SCR systems feed, meter, and control an aqueous urea solution AdBlue, also known as DEF (diesel exhaust fluid). Such fluids can have a corrosive effect on the component surfaces with which they come into direct contact. Thomas pumps are specially designed to address this risk. A further critical characteristic of DEF is that the aqueous solution freezes at temperatures below minus 10°C and expands in the process. Space has to be made for the resulting additional volume to prevent the components from leaking or failing to do their job. This is the reason why the systems supplied by our competitors often have to be emptied. Our products stand out for the fact that Thomas-developed pumps and valves can withstand freezing temperatures when full without any detrimental effects. This enables significant simplification of SCR systems.

We offer bespoke solutions tailored to the needs of our customers, which include metering and feed pumps as well as stop and transfer valves. These are typically used in the SCR systems run in cars, trucks, construction equipment, and stationary mechanical plants. In many such cases, the mounting space is limited, which means dual tank systems or multiple tank systems have to be installed. The system then directly feeds off a so-called “active tank”, which is topped up by the auxiliary tanks. Our transfer pump assumes this role as a feeding pump that operates as a directly controlled diaphragm pump.

Our metering pumps stand out for their minimal leakage and extremely precise delivery, which promotes exact metering and simplifies OBD (on board diagnostics) over a wide operating range. Our pumps are also designed to meet the long lifespan requirements of both car and truck systems. We employ different designs to suit the requirements of our customers, with the spectrum of options ranging from indirectly controlled diaphragm pumps to internal-flow linear reciprocating piston pumps.