Danfoss Angle-Seat Valves

Insensitive to dirt
Normally a servo-operated system is used when both high pressures and high capacities are needed. When the flow passes through the pilot system there will be a severe risk of blocking the small orifices due to the frequently dirty nature of cooling water. On the AV210 there is no servo-operated system. The AV210 is internally a valve seat mounted on a spindle. The spindle is the most sensitive valve part. On the AV210 the spindle is made of AISI 316, a high grade corrosion resistant material. The valve plate is made of PTFE with a high degree of resistance against both temperature and aggressive media.

Insensitive to media pressures and viscosity
The AV210 is externally operated. It means an air cylinder, integrated in the valve, provides the movement of the spindle. Air, neutral gases and fresh water can operate the cylinder. This design means that the control of the valve does not depend on flow rate/pressure loss across the orifice & is insensitive to the viscosity of the medium. The AV210 operates in viscosities up to 400 cSt. Switching the pressure in the cylinder from zero bars to the specified value controls the AV210 valve. The AV210 valve operates almost no matter what happens in the application.

Wide temperature range
The special valve design with no electrical parts, with FKM, PTFE and gun metal or stainless steel gives the possibility to use the valve in a wide temperature range: with 100% duty up to 180°C and for short periods even more. The AV210 goes down to -30°C without problems.

Good internal tightness even at high differential pressures
A typical externally operated valve has two basic designs; closing with the flow direction and closing against. The standard AV210 valve closes against the flow. Here the valve seat is pressurized through the valve orifice. It means the pressure will try to open the valve. Without success of course; due to a strong spring is closing the valve. When the valve is closing against the pressure, two advantages are obvious; the spindle is not placed in the medium all the time and the risk of water hammer is reduced significantly. The AV210 can also be used as closing with the flow if demanded. In this situation the pressure of the medium supplements the spring force, thus improving sealing. It also gives the possibility to increase the maximum differential pressure by increasing control pressure on the valve cylinder. This can only be recommended if there is no risk of water hammer. The AV210 valve is also available as a Normally Open version.

AV210 valves have a high capacity
The AV210 range has high Kv-values. Normally the diameter of the valve orifice is used to choose the capacity of a valve. It is an important parameter, but what can be even more important is the distance the valve plate is lifted from the orifice. On the AV210 the valve plate is lifted much more than the typical 25% of the valve diameter. It can be done because of the design of the cylinder with a long stroke combined with a spring with a high degree of compression. The internal shape of the valve body has influence on the capacity. The AV210 is designed for optimum capacity.

Reliable and unique design
The AV210 is designed for optimal function during a long life time. When the spindle is moving up and down during the operation of the valve the concentricity of the valve parts is vital for minimum load. On the AV210 the load is significantly reduced due to the unique design with moving piston, but with the piston ring fixed in the control head as a non-moving part. This design requires no cylinder, only a polished piston mounted direct on the spindle. In addition, the valve plate is designed as "floating" which means it is able to compensate for minor deviations and particles placed on the valve seat without giving additional load on the other valve parts.

Modular design
Due to the modular design of the AV210 valve range Danfoss is able to offer the optimal solution. ISO 228/1 thread is the standard connection; but welding spigots, tri-c1amp, NPT thread and flanges can be delivered optionally. For a certain valve orifice and pressure, a suitable control head must be chosen. On AV210 five sizes are available. To achieve the most beneficial solution, the control head corresponds with the valve size and pressure range. The standard version control head can be used up to 60° ambient temperature. For the more demanding application a high temperature version can be delivered optionally.

Accessories
For more demanding and specific application Danfoss offers accessories for the AV210 range. A manual opening device can be mounted on the control head. This makes it possible to operate the valve before the application is finished, for example if flushing the pipes is required during the construction period. AV210 can also be mounted with a flow limiter. This device stops mechanically the movement of the spindle, and can for example be used for dosing equipment, where several valves are expected to deliver the same quantity, even though they are mounted under different conditions. For the demanding application it can be necessary to know exactly the status of the valve. Position indicators, both with mechanical switches and with non-contact sensors giving a signal, are available.

  • High capacity basic program
  • 2/2-way
  • Angle-seated piston
  • NC version: Both closing against and with flow direction
  • NO version: Closing against the flow direction
  • Bronze or stainless steel valve body

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