High Pressure Filter Pi 420

Filtration Group


Related Documents:
Spec/Diagram PDF
Spec/Diagram PDF

Item Information:

High performance filters for modern hydraulic systems.  Nominal pressure 400 bar (5690 psi), nominal size up to 450.  Optional with reverse flow valve.

  • Modular system
  • Compact design
  • Minimal pressure drop through optimal flow design
  • Visual/electrical/electronic maintenance indicator
  • Threaded or flanged connections
  • Equipped with highly efficient glass fibre PS filter elements
  • Beta rated elements according to ISO 16889 multipass test
  • Elements with high differential pressure stability and dirt holding capacity
  • NPT- and SAE-connections on request
  • Worldwide distribution

Flow rate/pressure drop curve complete filter


y = differential pressure Δp [bar]
x = flow rate V [l/min]
3. Separation grade characteristics 4. Filter performance data

x=particle size [µm]

determined by multipass tests (ISO 16889)
calibration according to ISO 11171 (NIST)

tested according to ISO 16889 (multipass test)


PS elements with PS vst elements with
max. Δp 20 bar max. Δp 210 bar
PS    3     ß5(c)    ≥200 PS vst    3       ß5(c)   ≥200
PS    6     ß7(c)    ≥200 PS vst    6       ß7(c)   ≥200
PS    10   ß10(c)   ≥200 PS vst    10     ß10(c)  ≥200
PS    25   ß20(c)   ≥200 PS vst    25     ß20(c)  ≥200
Values guaranteed up to
10 bar differential pressure
Values guaranteed up to
20 bar differential pressure
5. Quality assurance
Filtration Group filters and filter elements are produced according to the following international standards:
6. Symbols
7. Order numbers
8. Technical specifications
Design: line mounting filter
Nominal pressure: 400 bar (5690 psi)
Test pressure: 520 bar (7400 psi)
Temperature range: -10 °C to +120 °C
  (other temperature ranges on request)
Bypass setting: Δp 7 bar ± 10 %
Filter head material: GGG
Filter housing material: St
Sealing material: NBR/PTFE
Maintenance indicator setting: Δp 5 bar ± 10 %
Electrical data of maintenance indicator:  
Maximum voltage: 250 V AC/200 V DC
Maximum current: 1 A
Contact load: 70 W
Type of protection: IP 65 in inserted and
  secured status
Contact: normally open/closed
Cable sleave: M20x1.5

The switching function can be changed by turning the electric upper part by 180° (normally closed contact or normally open contact). The state on delivery is a normally closed contact. By inductivity in the direct current circuit the use of suitable protection circuit should be considered. Further maintenance indicator details and designs are available in the maintenance indicator data sheet.

We draw attention to the fact that all values indicated are average values which do not always occur in specific cases of application. Our products are continually being further developed. Values, dimensions and weights can change as a result of this. Our specialized department will be pleased to offer you advice.

We recommend to contact us concerning applications of our filters in areas governed by the EU Directive 94/9 EG (ATEX 95). The standard version can be used for liquids based on mineral oil (corresponding to the fluids in Group 2 of Directive 97/23 EG Article 9). If you consider to use other fluids please contact us for additional support.

* Subject to technical alteration without prior notice.

In = Inlet
Out = Outlet
*1= Visual maintenance indicator
*2= Electrical upper section connector according DIN EN 175301-803, version: PiS 3092, 3105, 3115
*3= Electrical upper section connector according DIN EN 175301-804, version: PiS3102, 3122, 3110
*4= NG 300, 450 with drain screw G? DIN 910
DN25 according to SAE1" 6000 psi
DN38 according to SAE1?" 6000 psi
Flange, screw, o-ring not included in delivery.
9. Dimensions
10. Execution with reverse flow valve
Filters are normally designed for single- direction flow only. Reverse flows result in destruction of the cartridge. Some applications can require the medium to flow through the filter in both directions, however. The Pi 420 with a reverse flow valve can be used here. It allows medium flows in both directions, although it only filters in one. The liquid is not filtered in reverse mode. The reverse flow valve can be supplied with or without a bypass function.
11. Installation, operating and maintenance instructions
11.1 Filter installation
When installing the filter make sure that sufficient space is available to remove filter element and filter housing. Preferably the filter should be installed with the filter housing pointing downwards. The maintenance indicator must be visible.
11.2 Connecting the electrical maintenance indicator
The electrical indicator is connected via a 2-pole appliance plug according to DlN EN 175301-803 with poles marked 1 and 2. The electrical section can be inverted to change from normally open position to normally closed position or vice versa.
11.3 When should the filter element be replaced?
1. Filters equipped with visual and electrical maintenance indicator: During cold starts, the indicator may give a warning signal. Press the red button of the visual indicator once again only after operating temperature has been reached. lf the red button immediately pops up again and/or the electrical signal has not switched off after reaching operating temperature, the filter element must be replaced after the end of the shift.
2. Filters without maintenance indicator: The filter element should be replaced after the trial run or flushing of the system. Afterwards follow instructions of the manufacturer.
3. Please always ensure that you have original Filtration Group spare elements in stock: Disposable elements (PS) cannot be cleaned.
11.4. Element replacement
1. Stop system and relieve filter from pressure.
2. Filter sizes 300 and 450: empty the filter housing by removing the drain plug.
3. Unscrew the filter housing by turning counter-clockwise. Clean the housing using a suitable cleaning solvent.
4. Remove element by pulling down carefully.
5. Check o-ring, spigot and o-ring in the element locator for damage. Replace, if necessary.
6. Make sure that the order number on the spare element corresponds to the order number of the filter name-plate. To ensure no contamination occurs during the exchange of the element first open the plastic bag and push the element over the spigot in the filter head. Now remove plastic bag.
7. Lightly lubricate the thread of the filter housing and screw onto the filter head completely. After that unscrew the filter housing 1/8 to 1/2 return.
8. Check seals of vent drain plug - if necessary, please replace.
Torque drain plug 30 Nm.
11. Spare parts list