Pressure relief controllers

  • Overview
  • Documents
  • Tools and apps
  • FAQ
  • Case stories
  • Videos

Pressure and differential pressure relief controllers consist of a valve and a pressure actuator. Primarily used to limit a pressure (A) or differential pressure (PA)
over a system/substation/pump.

Controllers are normally closed: AV(P)A due to a normally closed valve and AF(P)A due to a stretching spring.

Pressure and differential pressure relief controllers are primarily installed into a bypass. They can be used to enable heat power distribution to other network connections or idle flow in case the connection(s) close(s) completely.

Pressure and differential pressure relief controllers can protect variable flow pumps from overload in the event that flow falls below minimum pump capacity. They relieve pump/application and forward heat power to other connections.

A pressure relief controller can also be installed into the return to maintain a higher desired (static) pressure in the system.

Features and benefits

Relief pump/application and forward heat power to other connections safely

Made for demanding systems, resistant to corrosion, cavitation and dirt

Connected system is protected against pressure surges, fluctuations, cavitation and noise


Type Name Language Valid for Updated Download File type

Tools and apps

Application guide


Yes you can. Open the control valve fully and set the max flow by adjusting the differential pressure. You can also calculate the appropriate differential pressure, but you need to know the exact capacity of the control valve.

We produce valves with a standard length. You can also find the measures in our datasheet or download 2D and 3D CAD drawing models from our product presentations. Please go to our product catalog where you will find links to documentation and drawings - follow the below link.

Do not stop turning the setting nut when the shaft hides into it. There is still round 100 mm stroke to do.

Case stories

  • Research Vessel with reduced need for fuel and reduced emissions complying the IMO environmental regulations
    Danfoss shaft generators drive down emissions on board

    The South Korean National Institute of Fishery Science is enjoying great fuel savings and 20-30% less emissions from its newest research vessel. A special shaft generator solution enabled the vessel to comply with the IMO environmental regulations effective in 2020.

  • In Helsinki a total of 667 addresses in a mix of large and small buildings and apartments have had the Leanheat software installed.
    Leanheat makes buildings smart

    In Europe, 30 percent of all energy consumption goes to heat or cool buildings. Danfoss has the solution to lower energy usage and improve indoor climate by adding a digital element: Leanheat software.

  • Solar heating plant reduces CO2 emissions by 15,700 tonnes annually
    Solar heating plant reduces CO2 emissions by 15,700 tonnes annually

    The world’s largest solar heating plant in Silkeborg, Denmark harnesses energy to heat the homes and workplaces of 40,000 citizens. It supplies 18-20% of the annual heat consumption in the city of Silkeborg, Denmark, which has an ambitious target of CO2 neutrality in heat production by the year 2030.

  • District energy as the heating and cooling solution in Teknopark Istanbul, Turkey

    Building: Office
    Application: Production of heating, cooling and domestic hot water
    Challenge: Design and construct customized district energy solutions for all buildings on the park
    Solution: Danfoss  designed and constructed 3 pre-assembled DSE substations containing control valves for the heating, cooling and domestic hot water, heat meters, self-acting controllers and electronic controllers connected to a central Building Management System. 

  • First ever district heating system with substations in Turkey

    600 residents in the town of Soma in Western Turkey now enjoy the comforts of a reliable and cheap heat supply from the town’s brand new district heating system. 

    In the coming years, more than 8,000 households will be joining the system that exploits the excess heat from the municipal power plant – a great improvement from the charcoal boilers of the past, and much less expensive.

  • District heating network in HafenCity, Hamburg, Germany

    The district heating supply in the new Hamburg city quarter "HafenCity" is a cost-effective and sustainable solution amongst other supplied by Danfoss.