Festo DFPI Series Instructions

DFPI-...-ND2P-C1V-...-A
Linear drive
Instructions | Operating
8126066
2020­02d
[8126068]
Translation of the original instructions
© 2020 all rights reserved to Festo SE & Co. KG
1

Safety

1.1 General Safety Instructions
– Only use the product in original status without unauthorised modifications.
– Only use the product if it is in perfect technical condition.
– Use only proximity sensors approved for the product.
– Take into consideration the ambient conditions at the location of use.
– Observe labelling on the product.
– Comply with all applicable national and international instructions.
– Comply with specified critical limits. Only compliance with the limit values
and/or load limits will enable operation of the product in accordance with the
relevant safety directives.
– Do not loosen or dismantle the pressure compensation element.
– Protect the device from fluctuations in pressure and excess operating temper­
ature. Use overpressure valves and pressure regulators.
– Before working on the product, switch off the power supply and secure it
against being switched on again.
– Store the product in a cool, dry, UV­protected and corrosion­protected envir­
onment. Ensure that storage times are kept to a minimum.
Operating medium
– Only use compressed air in accordance with the specifications
è 13 Technical Data.
– Use only unlubricated compressed air under normal conditions. Once the
product has been used with lubricated compressed air, it must continue to be
operated with lubricated compressed air only.
1.2 Intended Use
The linear drive DFPI is intended to drive linearly actuated, guided process valves
in process engineering systems, e.g. this includes guided slide valves and shut­
off valves. It is suitable for use in the process industry for:
– Water, wastewater, tap water, process water,
– Silo and bulk solids technology.
The stroke length of the drive usually corresponds to at least the nominal diamet­
er of the process valve, so that the slide valve can be completely opened and
closed with the DFPI.
The product is tailored to the requirements of the process industry.
1.3 Training of Qualified Personnel
The actions described in this document may only be carried out by qualified spe­
cialists.
2

Further information

– Accessories è www.festo.com/catalogue.
– Spare parts è www.festo.com/spareparts.
3

Service

Contact your regional Festo contact person if you have technical questions
è www.festo.com.
4

Product overview

4.1 Function
The compressed air applied at connection P is directed by the integrated valve
block alternately to the two piston chambers of the cylinder (depending on the
specified setpoint position). This causes the piston rod connected to the piston to
move backwards and forwards.
Festo SE & Co. KG
Ruiter Straße 82
73734 Esslingen
Fig. 1
Germany
The maximum possible exhausting of the cylinder chambers can be set independ­
+49 711 347­0
ently of each other using flow control screws D2 and D4.
www.festo.com
– D2 controls the exhaust when the piston rod advances.
– D4 controls the exhaust when the piston rod retracts.
This enables the maximum travel speed of 0 ... 100% to be influenced. The flow
control screws are completely open in the factory setting.
The DFPI ­...­ ND2P­C1V­A is protected against contamination by rubber plugs and
the DFPI ­...­ ND2P­C1V­PA is protected by the flange type socket.
8126066
Positions are specified via an analogue setpoint signal (4 ... 20 mA). The position­
ing of the piston rod or slide plate is controlled. The integrated positioner controls
the position of the piston rod within the available stroke range.
The integrated displacement encoder transmits the current position to the intern­
al positioner as an analogue signal. The positioner cyclically compares the set­
point and actual positions and transmits appropriate positioning signals to the
integrated valve block for positioning control.
The valve block controls the desired direction of movement by pressurizing one
cylinder chamber and simultaneously exhausting the other cylinder chamber with
restricted or unrestricted exhaust.
The current position is provided as an analogue current signal (4 ... 20 mA) via
the actual value output and can be evaluated by a higher­order controller as
required.
The drive has a factory­defined safety position. If the operating voltage supply or
the analogue setpoint value is outside the permissible range (e.g. in the event of
wire breakage), the piston rod is advanced (close process valve).
4.2
4.2.1
The DFPI­...­ND2P­C1V­...­A is an electro­pneumatic linear drive consisting of a
double­acting pneumatic cylinder with:
– integrated displacement encoder (potentiometer) for detection of the actual
position
– integrated valve block with directional control valves for controlling the pis­
ton rod
– integrated positioner for position control.
If required, proximity sensors can be installed in the existing slots for additional
binary querying of positions. A pressure compensation element prevents the
formation of condensate inside the housing in the event of temperature fluctu­
ations, thus protecting the internal electronics.
The pneumatic connections are freely accessible with theDFPI­...­ND2P­C1V­A
(connection G¼). The electrical connections are protected by a flange type sock­
et.
The electrical and pneumatic connections are protected against external mechan­
ical influences by a flange type socket with theDFPI­...­ND2P­C1V­PA. The flange
type socket has push­in connectors for the pneumatic components and an
exhaust port G¼ for local exhaust.
The following types of the linear drive depend on the piston diameter and may
vary from what is shown in è Fig.2 or è Fig.3:
– Position of the earth terminal (è identification on the product)
– Shape of the cylinder barrel
– Shape of the flange type socket.
For linear drives with a piston diameter of ³ 200 mm, the compressed air is sup­
plied at one end routed parallel to the cylinder barrel through an unprotected line.
Tie rod screws are used to attach the cylinder end cap.
The compressed air is supplied internally on linear drives with a piston diameter
of £ 200 mm. The cylinder end caps are screwed to the housing.
G
Configuration
Product design