Pressure relief valves for gear pumps

Pressure relief valves protect gear pumps and systems from excessive pressure. They limit the pressure in the system and divert or discharge the fluid when the set opening pressure is reached. This relieves stress on the pump, pipes, seals, and connected components.

Linn-Pumpen offers external pressure relief valves from the DB series as well as integrated safety valves from the F..U/DU series for this purpose. The selection depends on the flow rate, set pressure, fluid, viscosity, temperature, and installation conditions.

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Series

Select the appropriate pressure relief valve based on the installation situation: externally in the line or integrated into the gear pump’s cover.

DB series

Directly controlled seat valves for pressure limitation in the system

Flow rate: up to 250 l/min
Setting pressure: up to 100 bar
Installation: external in line or unit

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Pressure relief valves in the pump cover

Series F..U/DU

Safety valve in pump cover for series F and D

Flow rate: up to 124 l/min (depending on the pump)
Setting pressure: 2 / 20 bar
Installation: integrated safety valve in the pump

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External or integrated pressure relief valve?

DB Series – External Pressure Relief Valve

For installation in a pipeline or unit.
The DB series is a direct-acting seat valve designed to limit system pressure. It is suitable for applications in which an external pressure relief valve is installed outside the gear pump.

F..U/DU Series – Integrated Safety Valve

For F- and D-series gear pumps with a valve in the pump cover.
The F..U/DU series consists of F- and D-pumps with an integrated pressure relief valve. When the opening pressure is reached, the valve diverts flow internally from the discharge side to the suction side.

Important considerations for the design

The key factors are flow rate, desired opening pressure, fluid, viscosity, temperature, and installation location. A pressure relief valve must be compatible with the pump and the system and does not automatically replace a comprehensive safety system.

FAQ

When does a gear pump need a pressure relief valve?

A gear pump should be protected against excessive pressure, as it is a positive displacement pump and will continue to deliver fluid if the discharge side becomes blocked or the back pressure rises sharply. A pressure relief valve relieves pressure in the system when the set opening pressure is reached.

What is the difference between DB and F..U/DU?

The DB series is an external pressure relief valve designed for installation in piping or equipment. F..U/DU is a gear pump from the F or D series with an integrated safety valve in the pump cover.

When is an external pressure relief valve recommended?

An external pressure relief valve is useful when the pressure relief needs to be incorporated into the piping or the unit independently of the pump. It offers greater flexibility during installation and can be designed for higher flow rates and pressure ranges.

When is an integrated safety valve a good idea?

An integrated safety valve is a good choice when the pressure relief mechanism needs to be located directly in the pump cover of the gear pump. This design is particularly compact and is suitable for F and D pumps, provided the appropriate pressure setting range is sufficient.

For which media are pressure relief valves suitable?

Suitability depends on the medium, viscosity, temperature, and seal. Typical media include oils, lubricants, emulsions, water-glycol mixtures, diesel, heating oil, as well as paints and coatings. These media are also listed on the product pages for the valve series.