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Pressure relief controllers

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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

Tools and apps

Heat Selector

Danfoss Heat Selector is the best-in-class online selection tool that optimizes planning process for heating application experts.

Open Heat Selector

Application guide

FAQ

Can I limit a max flow with a differential pressure regulator?

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 design an installation and need lengths of valves from a project specification.

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.

I can only achieve half of the pressure setting on AFPA, but I need to set much more!

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

Case stories

City of Banja Luka
Danfoss partners with the city of Banja Luka to decarbonize district energy

The Challenge: Renovate 34 of the city’s largest heating substations
The Solution: Danfoss Leanheat® Monitor enables full substation digitalization
The Results: reduced heat consumption by 10%

Eurasburg
Successful transition from oil boilers to a local heating network in Eurasburg

In the Wittelsbacher Land near Augsburg the local network in Eurasburg supplies heat to 80 buildings using a wood chip heating system. Danfoss’ substations ensure efficient heating in all building types, and its modern SCADA solution enables remote system monitoring and management. 

Saleska valley, Slovenia
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The Saleska Valley district heating network is the second largest network in Slovenia, dating back to 1959. Since then, the demands have changed significantly and have challenged the hydronic balancing of the system which was optimized with new intelligent controllers Virtus.

Research Vessel with reduced need for fuel and reduced emissions complying the IMO environmental regulations
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SOUTH KOREA: 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.

Videos

Benefits of differential pressure and flow controllers in DH or cooling systems (constant flow)
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