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DISASSEMBLY

1. Regulator can be disassembled without removal from air

line.

2. Shut off inlet pressure. Reduce pressure in inlet and

outlet lines to zero. 

3. Turn adjustment (1 or 7) fully counterclockwise.
4. Disassemble in general accordance with the item

numbers on exploded view.

CLEANING

1. Clean parts with warm water and soap.
2. Rinse and dry parts. Blow out internal passages in body

with clean, dry compressed air.

3. Inspect parts. Replace those found to be damaged.

ASSEMBLY

1. Lubricate o-rings, valve stem (17), adjusting screw

threads and tip (5, 7) and the outer circumference and
both sides of the thrust washer (4) with a light coat of
good quality o-ring grease. 

2. Assemble the unit as shown on the exploded view. 
3. Torque Table

Item

Torque in Nm (Inch-Pounds)

2, 10 (Screw)

2,8 to 3,9 (25 to 35)

23 (Reverse flow valve on 

R74R models)

0,7 to 1,1 (6 to 10)

14 (Bottom plug)

2,3 to 3,4 (20 to 30)

WARNING

These products are intended for use in industrial

compressed air systems only. Do not use these products
where pressures and temperatures can exceed those listed
under 

Technical Data

.

If outlet pressure in excess of the regulator pressure

setting could cause downstream equipment to rupture or
malfunction, install a pressure relief device downstream of
the regulator. The relief pressure and flow capacity of the
relief device must satisfy system requirements.

The accuracy of the indication of pressure gauges can

change, both during shipment (despite care in packaging)
and during the service life. If a pressure gauge is to be
used with these products and if inaccurate indications may
be hazardous to personnel or property, the gauge should be
calibrated before initial installation and at regular intervals
during use.

Before using these products with fluids other than air,

for non industrial applications, or for life-support systems
consult Norgren.

TECHNICAL DATA

Fluid: Compressed air
Maximum pressure: 20 bar (300 psig)
Operating temperature*: -20° to +80°C (0° to +175°F)
* Air supply must be dry enough to avoid ice formation at 

temperatures below +2°C (+35°F).

Typical flow with 10 bar (150 psig) inlet pressure, 6,3 bar 

(90 psig) set pressure and 1 bar (15 psig) droop from 
set: 105 dm

3

/s (220 scfm)

Gauge ports: 

1⁄4 PTF with PTF main ports
Rc1/4 with ISO Rc main ports
Rc1/8 with ISO G main ports

Materials:

Body: Aluminum
Bonnet : Aluminum
Valve: Brass
Elastomers: Nitrile
Bottom plug: Acetal

REPLACEMENT ITEMS

Service kit (includes items circled on exploded view)

Relieving.............................................................4381-700
Non-relieving ......................................................4381-701

Tamper resistant cover and wire ..............................4355-51

PANEL MOUNTING DIMENSIONS

Panel mounting hole diameter: 52 mm (2.06")
Panel thickness: 2 to 6 mm (0.06" to 0.25")

INSTALLATION

1. Shut off air pressure. Install regulator in air line -

with air flow in direction of arrow on body,

upstream of lubricators and cycling valves. R74R 
reverse flow regulators can be installed upstream or 
downstream of cycling valves,

as close as possible to the device being serviced.

at any angle.

2. Connect piping to proper ports using pipe thread sealant

on male threads only. Do not allow sealant to enter
interior of regulator.

3. Install a pressure gauge or plug the gauge ports. Gauge

ports can also be used as additional outlets for regulated
air.

4. Install a Norgren general purpose filter upstream of the

regulator.

ADJUSTMENT

1. Before applying inlet pressure to regulator, turn

adjustment (1 or 7) counterclockwise to remove all force
on regulating spring.

2. Apply inlet pressure, then turn adjustment (1 or 7)

clockwise to increase and counterclockwise to decrease
pressure setting.

3. Always approach the desired pressure from a lower

pressure. When reducing from a higher to a lower
setting, first reduce to some pressure less than that
desired, then bring up to the desired pressure. 

NOTE

With non-relieving regulators, make pressure
reductions with some air flow in the system. If
made under no flow (dead-end) conditions, the
regulator will trap the over-pressure in the
downstream line. 

4. KNOB ADJUSTMENT. Push knob down to lock pressure

setting. Pull knob up to release. Install tamper resistant
cover and wire (see 

Replacement Items

) to make setting

tamper resistant.

5. T-BAR ADJUSTMENT. Tighten lock nut (8) lock pressure

setting.

IM-200.200

(4/98)

a subsidiary of IMI plc

© Norgren 1998

1

13

7

8

9

10

11

6

2

3

4

5

12

21

22

17

15

18

16

14

19

20

23 (R74R only)

R74G, R74R 

Installation & Maintenance 

Instructions

Pressure Regulator

R74

★★★ 

★★★

Thread Form

A....PTF
B....ISO Rc taper
G....ISO G parallel

Port

3 ....3/8"
4 ....1/2"
6 ....3/4"

Flow Type

G....Uni-directional
R.... Reverse

Spring (Outlet Pressure Range) *

F ....0,3 to 4 bar (5 to 60 psig)
M...0,3 to 10 bar (5 to 150 psig)
S....0,7 to 17 bar (10 to 250 psig)

Gauge

G....With
N....Without

Diaphragm

N....Non-relieving
R....Relieving

Adjustment

K....Knob
T ....T-bar

* Outlet pressure can be adjusted to pressures in excess of, and less than, those specified. Do not use these units to control pressures outside of the specified ranges.

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