Refrigeration dryer WDF-70 with filters – G 1/2", 1,167 l/min
Code: WDF-70
Related products
Product detailed description
The WDF-70 refrigeration dryer dries compressed air to a pressure dew point of +3 °C, i.e. water class 4 according to ISO 8573-1, and at the same time filters it with a built-in 1 µm pre-filter and 0.01 µm fine filter. It handles 1,167 l/min (70 m³/h) at 7 bar, operates in the range of 4 to 16 bar and connects via a G 1/2" thread; power supply 230/50 V/Hz.
Dry, clean air protects the compressed air network, air receiver, valves, pneumatic cylinders and tools against corrosion and water, and in a paint shop it prevents surface defects caused by moisture. Because both filters are inside the dryer, you do not need to buy or install a separate pre-filter and after-filter.
It belongs to the range of WALTER WDF refrigeration dryers with integrated filters: a dryer and two filters in one cabinet, a Digi-Pro controller and R134a refrigerant.
Technical parameters
| Parameter | Value |
|---|---|
| Flow rate at 7 bar | 70 m³/h (1,167 l/min) |
| Working pressure | 4 to 16 bar |
| Pressure dew point | +3 °C (water class 4 according to ISO 8573-1) |
| Built-in filters | WFS pre-filter 1 µm, WFC fine filter 0.01 µm |
| Spare elements | FE 65 KIT / FE 70 KIT / FE 75 KIT set |
| Connection | G 1/2" |
| Power supply | 230/50 V/Hz |
| Power input | 0.38 kW |
| Pressure drop | 250 mbar |
| Refrigerant | R134a, charge 0.32 kg |
| Inlet air temperature | up to +60 °C |
| Room temperature | +4 to +50 °C, indoor installation only |
| Condensate drainage | solenoid valve with timer relay, manual button |
| Control | Digi-Pro controller |
| Circuit protection | klixon, fan pressure switch 9–12 bar, refrigerant temperature sensor 45 °C |
| Dimensions L × W × H | 370 × 372 × 706 mm |
| Weight | 35 kg |
Dimensions and connections
Length 370 mm, width 372 mm, height 706 mm, weight 35 kg. The drawing shows the position of the G 1/2" air connections, the condensate drain, the controller and the grilles through which the condenser cooling air flows – keep the space around them clear.
How it works
In the heat exchanger, the air is first pre-cooled by the dry air leaving the dryer, then the refrigerant cools it to a dew point of +3 °C and the water vapour condenses. The centrifugal separator separates the droplets and the condensate drains away. At the outlet, the dry air is warmed up again and passes through the pre-filter and fine filter.
Filters and controller
The WFS 1 µm pre-filter and WFC 0.01 µm fine filter capture solid particles and oil aerosol. The Digi-Pro controller displays the pressure dew point, signals alarms (high and low temperature, pressure, sensor failure) and uses the FIL alarm to remind you to replace the filters – always replace both elements; without an alarm, replace them once a year. The condensate is discharged by a timer-controlled valve, and manually with the MANUAL DRAIN button.
Alarms on the display
| Code | Meaning |
|---|---|
| tAL | low temperature in the refrigerant circuit |
| tAH | high temperature in the refrigerant circuit |
| FIL | time to replace the filter elements |
| hSE | general inspection due |
| HP | high pressure in the refrigerant circuit |
| Pr1 | temperature sensor failure |
| hFI | the dryer has reached its permitted operating time (operating hours) |
| tSH | high temperature in the compressor suction line |
Installation and maintenance
- place it on a level surface indoors and leave at least 50 cm around it for servicing and the flow of cooling air
- the room temperature should be +4 to +45 °C (technical limit +50 °C), with no chemicals that attack copper and aluminium
- keep the condensate drain free, without any narrowing or back pressure
- only switch the dryer off when no air is flowing through it
- clean the condenser once a month and the condensate drain filter every 6 months
- replace the filter elements (FE 65 KIT / FE 70 KIT / FE 75 KIT set) after the FIL alarm, or once a year without an alarm – always both
Where it is suitable
- pneumatic tools: impact wrenches, spray guns and blow guns
- paint shops and powder coating
- car repair shops and tyre services
- joinery and metalworking workshops
- CNC machines, pneumatic cylinders and valves of automated lines
- laboratories and metrology
Position in the system
The dryer goes downstream of the compressor and air receiver. The inlet air may be at most +60 °C; cool warmer air with an aftercooler first. It does not need a separate pre-filter or after-filter; for air free of odours and oil vapours, add an activated carbon filter downstream of it. For a dew point below 0 °C, you need a desiccant dryer.
For other sizes, see WDF refrigeration dryers.
Additional parameters
| Category: | Compressed air dryers for compressors |
|---|---|
| Pressure: | 16 bar |
| Connecting: | 1/2" |
| Motor power: | 380 W |
| Mains voltage: | 230/50 V/Hz |
| Noise: | 45 dB(A) |
| Dimensions: | 370 × 372 × 706 mm |
| Weight: | 35 kg |
| Filtration: | 1 µm, 0.01 µm |
| Condensate discharge: | Automatic, Timed drain |
| Flow: | 1,167 l/min |
| ISO class: | x/4/x - ISO 8573.1 |
| Equipment: | Bleeding by time valve, Control unit LED display, Filtration, Automatic draining of condensate |
| Refrigerant: | Refrigerant R134a |
| Pressure dew point: | +3 °C |
| Dryer type: | Condensation dryer |
| Filtration stage: | Dust filter 1 µm, Microfilter 0.01 µm |
| In stock: | External warehouse |
| Dimensions: | 370 x 372 x 706 mm |
| Weight: | 35 kg |
| Integrated pre-filter: | 1 um |
| Integrated microfilter: | 0.01 µm |
| Pressure drop: | 250 mbar |
Product rating
Be the first who will post an article to this item!
WALTER Kompressortechnik is a manufacturer of compressors and compressed air treatment based in Łódź, Poland. We offer its cast-iron piston compressors, screw compressors in seven series and WDF refrigeration dryers with built-in filters, plus spare elements and WKTT oil.
The cast-iron piston machines have a low-speed pump unit that copes with daily use in a workshop, tyre service or paint shop. The screw compressors are built for continuous operation: fixed speed or with an inverter, two-stage, on an air receiver or with a dryer.
From 2.2 to 315 kWWALTER series: piston, screw and dryers
Cast-iron piston WK, VWK and HWK
For workshops, tyre services and paint shops. The low-speed cast-iron pump unit copes with daily use and can be repaired.
- 2.2 to 7.5 kW, 29 models
- horizontal, vertical or base-plate unit
- HWK for 13 and 15 bar, WKM 700 on petrol
SK SP and SKTG SP — belt drive
High output in a small footprint. Fixed speed, 5.5 or 7.5 kW, standalone or on a receiver.
- delivers 0.85 and 1.15 m³/min at 8 bar
- receiver 270, 300 or 500 l
- COMBO with dryer and filters
SK KSP — fixed speed
For steady air demand. The airend is connected to the motor by a coupling, with no belt.
- 11 to 315 kW, 17 models
- pressure 8, 10 or 13 bar
- max. 3 ppm oil mist in the air
SF KSP — variable speed drive
When demand varies during the shift. The inverter matches the speed to demand, so the machine does not idle.
- 5.5 to 315 kW, 19 models
- up to 35% less energy with varying demand
- IE4 motor, IE5 as an option
SFTG KSP — inverter on a receiver
A complete package in one unit. The inverter compressor sits directly on the pressure vessel.
- 5.5 to 15 kW, 14 models
- receiver 270, 300 or 500 l
- COMBO with dryer and filters
SF DSP — two-stage compression
For machines that run whole shifts. Two compression stages and an IE5 magnetic motor with inverter.
- 22 to 315 kW, 13 models
- on average 12% more air than a single-stage machine
- direct 1:1 drive, no belt
SLC Laser Cut — 16 and 20 bar
Air as the cutting gas for lasers. Higher pressure than a normal workshop needs, in three models.
- 15 to 22 kW
- SLC 22 with inverter for 16 or 20 bar
- SLCTG 15 with dryer and five filters
WDF refrigeration dryers
A dryer and two filters in one cabinet. Dries compressed air to a +3 °C dew point and filters it straight away.
- 22 sizes, 383 to 97,500 l/min
- pre-filter 1 µm and fine filter 0.01 µm
- spare elements in FE KIT sets
Not sure whether you need a piston or a screw compressor? The selection calculator works out the output you need from your tools and suggests a machine.
Choose a compressorWALTER compressors side by side
| Series, design, power, pressure and version | ||||
|---|---|---|---|---|
| Series | Design | Power | Pressure | Version |
| Cast-iron WK, VWK, HWK | piston, cast-iron pump unit | 2.2–7.5 kW | 10, 13 and 15 bar | horizontal, vertical, base-plate unit |
| WKM 700-7/38 | piston, Honda petrol engine | 4.3 kW | 10 bar | two 19 l tanks on a wheel |
| SK SP and SKTG SP | screw, belt, fixed speed | 5.5 and 7.5 kW | 8, 10, 13 bar | standalone, on a receiver, COMBO |
| SK KSP | screw, direct drive, fixed speed | 11–315 kW | 8, 10, 13 bar | standalone machine |
| SKTG KSP | screw, direct drive, fixed speed | 11 and 15 kW | 8, 10, 13 bar | on a 500 l receiver, COMBO |
| SF KSP | screw, direct drive, inverter | 5.5–315 kW | 8, 10, 13 bar | standalone machine |
| SFTG KSP | screw, direct drive, inverter | 5.5–15 kW | 8, 10, 13 bar | on a 270–500 l receiver, COMBO |
| SF DSP | two-stage screw, inverter | 22–315 kW | 8, 10, 13 bar | standalone machine |
| SLC Laser Cut | screw, for laser cutting | 15–22 kW | 16 and 20 bar | standalone, COMBO with dryer |
For most screw machines you choose 8, 10 or 13 bar. The higher the pressure, the less air the compressor delivers.
How to choose a WALTER compressor
1. Work out the demand
Add up the tools that run at the same time and allow about 30% for leaks and future extensions. Choose by free air delivery, not by intake volume.
2. Piston or screw
If you use air intermittently, a cast-iron piston compressor is enough. If the compressor runs for most of the shift, choose a screw compressor.
3. Fixed speed or inverter
With steady demand, the fixed-speed SK series is enough. If demand varies during the shift, the SF series with inverter saves up to 35% energy.
4. Dry and maintain
For dry air, add a WDF dryer after the compressor or choose the COMBO version straight away. WALTER screw compressors are serviced every 2,000 operating hours.
Frequently asked questions
- What does the number in a WK piston compressor name mean?
- The number after the letters is the approximate intake in l/min, the number after the dash is the motor power in horsepower, not kilowatts. WK430-3,0 has a 2.2 kW motor, WK650-5,5 a 4.0 kW motor. Choose by free air delivery: 340 to 1,100 l/min across the range.
- Is there a difference between WK and the older GK?
- Mechanically no, it is the same platform in a new generation. WK430 = GK420, WK550 = GK530, WK650 = GK630, WK900 = GK880 and WK1500 = GK1400. The old designation on the label helps when ordering spare parts.
- What do the abbreviations in screw compressor names mean?
- F = inverter, TG = on a receiver, KSP = direct drive without a belt, SP = belt drive, DSP = two-stage compression and COMBO = with dryer and filters. The number before the slash is the power in kW, after the slash the receiver volume in litres.
- When is an inverter worth it?
- When air demand varies during the shift. The inverter matches the speed to demand and saves up to 35% energy compared with a fixed-speed machine. With steady demand, a simpler fixed-speed machine pays off.
- Do you have a compressor that needs no electricity?
- Yes, the petrol WKM 700-7/38 with a Honda GX200 engine: 316 l/min, 10 bar, two 19 l tanks on a wheel. Because of the exhaust fumes, it may only be used outdoors.
- How often are the WDF dryer elements replaced?
- When the controller shows the FIL alarm, otherwise once a year, and always both elements together. Choose the FE KIT set by dryer size and the marking on the cap of the old element.
Free air delivery of the screw compressors is given to ISO 1217, Annex C. Technical data of the WDF dryers come from the manufacturer’s manual and website. WALTER is a brand of WALTER Kompressortechnik Polska, based in Łódź.
| Manufacturing company : | Walter Kompressortechnik Polska Sp. z o.o. |
|---|---|
| Address : | ul. Świętej Teresy od Dzieciątka Jezus 180, 91-222 Łódź, Poland |
| E-mail : | biuro@walterpolska.pl |