Pressure regulator FDR 1/4", 750 l/min, 0.1-3 bar
Code: FDR-3
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Product detailed description
The KNOCKS FDR-3 pressure regulator sets the outlet pressure from 0.1 to 3 bar and holds it precisely – with a control accuracy of 15 mbar – even when the network pressure fluctuates and air consumption changes. It is a robust precision regulator without a pilot stage: the spring presses directly on the diaphragm, so it does not need finely filtered air and also handles lubricated air. When the outlet pressure rises above the setting, it releases the excess by itself.
FDR 11 series, connection G 1/4", flow rate 750 l/min. It belongs to the FDR high-precision pressure regulators.
Specifications
| Parameter | Value |
|---|---|
| Code | FDR-3 |
| Manufacturer | KNOCKS FLUID-Technik |
| Manufacturer type | KNOCKS FDR.11 E3 |
| Series | FDR 11 |
| Connection | G 1/4" |
| Control range | 0.1–3 bar |
| Inlet pressure | max. 16 bar |
| Flow rate | 750 l/min (inlet pressure 8 bar, see graph) |
| Control accuracy | 15 mbar |
| Pilot stage | no |
| Secondary venting | 100 l/min |
| Own air consumption | 0.2 l/min (depending on the outlet pressure) |
| Valve seat bore | 3.5 mm |
| Pressure gauge connection | G 1/4" (pressure gauge not included) |
| Mounting | on a wall or frame with a bracket |
| Adjustment | adjusting spindle with lock nut |
| Operating temperature | −35 to +60 °C |
| Medium | lubricated and non-lubricated compressed air and neutral gases, fine filtration not required |
| Material | zinc die-cast body, NBR diaphragm and seals, free of non-ferrous metals |
| Dimensions (width × height) | 60 × 143 mm |
| Weight | 0.9 kg |
Dimensions and flow curve
Manufacturer’s graph for FDR-3: how the outlet pressure changes as the flow rate increases at an inlet pressure of 8 bar. The lines start at the set pressure – the longer the horizontal section, the more air the regulator delivers without a change in pressure.
Installation and adjustment
- install a compressed air filter upstream of the regulator – fine filtration is not required, the regulator also handles lubricated air
- do not swap the inlet and outlet – the regulator works in one direction only
- the pressure gauge is supplied separately: choose a pressure gauge with a G 1/4" thread and a range slightly above the pressure you will set
- set the pressure from below: loosen the lock nut and the spindle to below the required value, then slowly increase it until the pressure gauge shows the required pressure; finally tighten the lock nut
- the regulator is fixed to a wall or frame with the W LRN stainless steel bracket
Accessories
- wall or frame mounting: W LRN stainless steel bracket
- pressure gauge with G 1/4" thread (not included)
- repair kit: LRN14-REP
- further parts: spare parts and accessories for pressure regulators
Do you need more precise control from 0.05 bar with the same G 1/4" thread? The FDR 02 regulator FDR02-2 has an accuracy of 5 mbar, and the FDR 07 FDR07-8 delivers up to 1,250 l/min.
Additional parameters
| Category: | High-precision air pressure regulators FDR |
|---|---|
| Pressure: | 16 bar |
| Dimensions: | 60 × 143 mm |
| Weight: | 0,9 kg |
| Flow: | 750 l/min |
| Regulatory range: | 0.1 to 3 bar |
| Thread: | G 1/4" |
Product rating
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KNOCKS FLUID Technik is a German manufacturer of compressed air treatment. Heinz Knocks founded the company in 1970 as a one-man business. Today it is run by a non-profit foundation, and around 200 people at its headquarters in Selm develop and make pressure regulators, filters and lubricators.
With us you will find the modular FUTURA range, which can also be used in potentially explosive atmospheres, plus precision, remote-controlled and electrically controlled regulators, stainless push-in fittings, hose barb connectors, union fittings, anti-vibration mounts for compressors, digital pressure gauges, pressure switches and ball valves.
Since 1970What we offer from KNOCKS
FUTURA air treatment units
Modular air treatment up to 16 bar. Filters, regulators, lubricators and valves that you combine into a unit in any order.
- 4 sizes with G 1/4″ to 1″ threads
- bodies in glass-fibre reinforced polyamide
- sizes 1, 2 and 4 also for ATEX zones
FUTURA pressure regulators
Constant pressure for tools and machines. They reduce line pressure to the set value and relieve any excess themselves. A pressure gauge is included.
- ranges from 0.1–1 to 0.5–16 bar
- precision version accurate to ±25 mbar
- flow up to 14,200 l/min
DRPE proportional regulators
Pressure set by an electrical signal. A built-in transducer converts the signal from your control system into outlet pressure.
- 0–10 V or 4–20 mA signal
- output from 0–1 to 0–10 bar
- IP65 protection, M12 connector
Stainless push-in fittings
For food processing and chemicals. Body, ring and thread in AISI 316 stainless steel, FKM seals.
- tubes from 4 to 16 mm
- pressure from −1 to 15 bar
- M5, G and R threads up to 1/2″
Hose barb connectors
A simple joint for soft hoses. Straight, T, Y, L and X connectors in POM for low-pressure lines in automation.
- barbs from 3 to 25 mm
- POM resists petrol, diesel and oils
- pressure up to 8 bar
Union nut fittings
A secure joint for plastic tubing. Body and nut in anodised aluminium: straight fittings with male or female thread and elbows.
- tubes from 4.3/3 to 12/9 mm
- M5 to G 1/2″ threads
- pressure up to 10 bar
Anti-vibration mounts
No compressor vibration in the floor. A rubber cylinder between two steel plates absorbs the vibration of the machine.
- 40, 50 and 75 mm diameter
- M8, M10 and M12 threads
- male or female, one- or two-sided
Digital pressure gauges
Exact pressure on a display. Compact MAKP gauges for panels and MDG gauges with a stainless connection.
- MDG from −1 to 2,000 bar
- MDG accuracy 0.5 %
- MAKP with CR2032 battery, IP65
Looking for a hose, a quick coupling or another fitting for your unit? Couplings and fittings for compressed air are all in one category.
All couplings & fittingsKNOCKS regulators side by side
| Type, use, setting and connection | ||||
|---|---|---|---|---|
| Type | Used for | Pressure setting | Inlet pressure | Connection |
| BLP | constant pressure right at the blow gun | fixed 2 to 8 bar | up to 15 bar | G 1/4″ |
| FUTURA R | standard pressure setting for tools and machines | 0.1–1 to 0.5–16 bar | up to 16 bar | G 1/4″ to 1″ |
| FUTURA RP | measuring and test equipment, accuracy ±25 mbar | 0.1–1 to 0.5–16 bar | up to 16 bar | G 1/4″ to 1/2″ |
| FDR | finest setting and pressure stability | 0.05–2 to 0.05–10 bar | up to 16 bar | G 1/4″ and 1/2″ |
| DRI with DRF | high flow, pressure set remotely by a pilot regulator | set by the DRF pilot regulator | up to 25 bar | G 1/2″ to 2″ |
| DRPE | pressure controlled by a 0–10 V or 4–20 mA signal | 0–1 to 0–10 bar | up to 13 bar, by range | G 1/4″ |
FDR and DRF regulators need air filtered to 5 µm and free of oil.
How to build a FUTURA unit
1. Choose the size
The size determines the thread, the flow and the parts that belong to the module. The range comes in sizes 0, 1, 2 and 4 with G 1/4″ to 1″ threads. Only modules of the same size can be joined into one unit.
2. Order the modules
In the direction of air flow, the filter comes first, then the regulator and finally the lubricator. A shut-off valve and a soft-start valve can go in front of them.
3. Join and mount
Join the modules with a connecting kit of two frames and a sealing ring. A connecting kit with a bracket fixes the unit to the wall, a single module is held by an angle bracket.
4. Maintain
Replace a clogged filter element and top up the lubricator when the oil drops to the lower mark. Clean plastic bowls only with a damp cloth, as solvents damage them.
Frequently asked questions
- Can FUTURA be used in explosive atmospheres?
- Yes, sizes 1, 2 and 4. According to the declaration under Directive 2014/34/EU, they can be used in zones 1 and 2 with explosive gases and zones 21 and 22 with combustible dust, temperature class T4. Size 0, electrically operated valves and soft-start units, manifolds with a pressure switch and clogging indicators are not suitable there. The medium may only be dry compressed air or an inert gas.
- Two-part or three-part unit?
- A two-part unit has a filter regulator in one body with a lubricator next to it, saving space and one joint. A three-part unit combines the filter, regulator and lubricator as three separate modules. Both filter to 5 µm and come with a pressure gauge.
- When do I need a precision regulator?
- When the pressure has to stay constant even if the inlet pressure varies, for example on measuring and test equipment. FUTURA precision regulators hold the pressure to ±25 mbar, and FDR regulators can be set from as low as 0.05 bar.
- What is the BLP regulator for?
- This small regulator with a G 1/4″ thread screws straight onto the inlet of a blow gun and holds a fixed outlet pressure of 2 to 8 bar, depending on the type. The gun then does not blow at full line pressure and uses less air.
- Which anti-vibration mount should I put under a compressor?
- It depends on the machine feet. If a foot has a plain hole, choose a mount with a male thread; if a bolt sticks out of it, choose a female thread. The diameter should be at least as large as the foot: 40 mm for smaller compressors, 50 mm for standard stationary ones and 75 mm for heavy piston units. Always fit a full set, usually four for a compressor with an air receiver.
- Where are stainless push-in fittings used?
- In the food, chemical and pharmaceutical industries and wherever the environment is aggressive or hygiene requirements are high. The body, ring and thread are made of AISI 316 stainless steel with FKM seals, and the fittings handle pressures from −1 to 15 bar.
KNOCKS FLUID-Technik GmbH is based in Selm, Germany, and is certified to ISO 9001 and ISO 14001. We will send you the declaration under Directive 2014/34/EU for the FUTURA range on request.