Providing Solutions – Exceeding Expectations – Satisfying Customers

Schroeder Valves is a global specialist in designing and manufacturing protective pump fittings based in Gummersbach, Germany. For more than 60 years we have been producing superior quality valves for refineries and power plants, the chemical industry, the offshore sector and, more recently, for the production of renewable energies.

SHP series

SHP series automatic recirculation valve for high pressure applications, low-wear operation and high load fluctuations 

The SHP series automatic recirculation valve protects pumps and equipment from damage that can occur due to the flow rate falling below the permissible minimum. The innovative design ensures that pumps and equipment are reliably protected, even in situations involving highly fluctuating pump loads and long periods of operation under extreme partial load conditions. This is achieved using a special fully automatic minimum flow control system that ensures the release of a modulating adaptive minimum flow. In addition, the wear-intensive extreme partial load range is deliberately overridden. The shut-off and pressure reduction functions are both functionally and physically separate from each other. This makes the SHP Series the ideal fitting for applications involving very flexible operating conditions, such as those commonly found in modern power plants, for example.

SSV series


With bypass throttles or bypass return valve

The automatic recirculation control (AR) valves from our SSV series automatically protect centrifugal pumps against wear, total loss and damage, which can occur due to dry running or during low-load operation. Our recirculation valves have historically proven exceptional reliability and low pressure loss over time. They are not susceptible to interference and are very low maintenance. In addition, they require no additional power supply or any kind of control unit, thus ensuring low operating costs.

SMV series

SMV SERIES MULTIFUNCTIONAL VALVES SMV With venting nozzle for media with a low boiling point

The Schroeder SMV series multi-functional valve is an automatic recirculation valve that is equipped with an automatic venting nozzle in addition to the minimum flow control and non-return device in the main feed. It permanently ensures that the stationary pump and standby pump are automatically vented and thus remain filled with liquid at all times.

SMA series

SMA SERIES AUTOMATIC MINIMUM FLOW SYSTEM SMA Automatic minimum flow system with "OPEN/CLOSED" control

The SMA 63/64 automatic minimum flow system is a protective pump fitting. It automatically protects centrifugal pumps against damage that may occur as a result of the partial evaporation of the pump content when the pumps are operated under low load. As soon as the main pump flow falls below a predetermined value, the valve opens the bypass and safely drains the minimum volume, even if the pumping volume in the main flow direction drops to zero.

The bypass is always completely opened or closed through its pilot-controlled valve piston (15/for illustration, see page 3 of SMA 63). This "OPEN/CLOSED" control makes it possible to increase the previous load limit of the valves from 200 bar to 400 bar (pumping pressure). The preferred utilization range is thus between PN 250 and PN 400 or ANSI CLASS 2500. The bypass amount may be up to 35% of the main pumping volume. The valve functions without an additional source of energy.

SR/SA series


The SR/SA valve type has been designed to control liquid media at high and very high pressures. The control valve is able to safely withstand pressures up to 600 bar and media temperatures of up to 400 °C. It is suitable for use both as a stand-alone shut-off valve (type SA) as well as for flow-control (type SR).

When used for pump protection, SR/SA valves are mainly used in modern process control and monitoring systems. They make it possible to accurately adjust the minimum volume regulation to our customers' system requirements. The use of actuators and sensors allows the valve to be fully integrated in modern process technology. SR/SA valves therefore extend Schroeder's product range to include control valves. They make a valuable contribution to low-energy, low-wearing pump operation.

SSD series

SSD SERIES MULTIPORT THROTTLES SSD For consistent pressure reduction

Multiport throttles are used to reduce the pressure and flow volume of liquid media.


The multiport throttles are used in nominal widths ranging from DN20 to DN500, in pressure steps up to PN640 and up to a permissible media temperature of 400°C. The throttle housings are normally made of 1.0460 (C22.8) steel suitable for pressurized vessels, but can also be made of various types of stainless steel, depending on the medium.


Configuration takes place in accordance with the AD 2000/EN 13445 regulations. The products are CE-labeled in accordance with the DGR 97/23 EC directive on pressurized devices and a conformity statement is issued. All hazard groups in categories 1 to 4 are included in the certification according to Module H1 (DGR 97/23 EC).

SDV series


Our back pressure device does not allow the static pressure in the upstream pipe to fall below a defined minimum value. It does this independently of the flow volume. This means that the specified minimum pressure is maintained, from the nominal flow rate to the smallest volume. Normally back pressure devices are used to avoid cavitation and partial evaporation in the pumping medium. By increasing the pressure level in the system component to be protected, they stop local steam pressure from falling below requirements. The SDV has an integrated return function, i.e. the system is also protected against reverse flow if needed.

Active Principle

The active principle of the SDV is based on a spring-loaded locking cone. The cone and spring are coordinated in such a way that once the specified holding pressure has been reached, the pressure force is sufficient to lift the cone out of its seat, thus permitting flow. Unlike conventional back pressure devices / counter-pressure regulators, the cone of our back pressure device has been equipped with a control profile. This allows the throttle surface at the cone seat to accurately adapt to the relevant flow rate, thereby minimizing the unfortunate tendency of spring-loaded locking devices to produce knocking or hammering noises at low flow rates. The SDV is therefore suitable for systems with a wide operating range and frequent partial load operation.

Further information about the product series may be obtained in the datasheet.



The manually operated connection with a step throttle is used to drain the bypass volume through a manually operated valve combination. This connection is recommended to protect the internal parts of the bypass under extreme operating conditions, for example at high differential pressure and frequent operation in the bypass range, as well as when filling and starting up the system.


The start-up trim (SUT) replaces the valve head when cleaning and starting up the system, thus protecting the internal parts of the bypass (optional, permanently open bypass outlet). The SUT can also be used as an alternative to the manually operated connection (see above).


The SDV pressure maintenance device avoids cavitation and evaporation in pipes. The functionality of the SDV corresponds to a variable throttle distance that depends on the volume flow.


The SRV attenuation valve is positioned on the SSV free-wheeling return valve and reduces pressure surges during frequent switching, for example in the case of descaling systems in steel mills.



We have more than six decades of experience in the development and manufacture of protective pump fittings. During this time we have constantly expanded our know-how and repeatedly demonstrated our competence.

Thanks to our traditionally close cooperation we know the needs and requirements of our customers. Our Engineering Department will examine each individual case and will work on appropriate product modifications and innovations.

Our highly trained staff will assist you with their technical expertise and for the mutual sharing of knowledge. Feel free to contact us at any time.