ROTORCOMP NK 100 User manual

Operating Manual
SCREW COMPRESSOR COMPACT MODULE
NK 100 / NK 100 G
[en] 09/2008

© Copyright ROTORCOMP VERDICHTER GmbH, 2008
All rights reserved.
No duplication, modification or translation beyond the degree permitted by the applicable copyright laws
is permitted without prior written approval.
The information contained in this document is subject to change without prior notice.
This document is not subject to the change service.
Printed in Germany
ROTORCOMP VERDICHTER GmbH
Industriestraße 9
82110 Germering, Germany

Operating Manual - NK 100
[en] 09/2008 i.1
1 Foreword......................................... 1.1
1.1 General ............................................ 1.1
1.2 Scope............................................... 1.1
1.3 Change service................................ 1.1
1.4 Abbreviations ................................... 1.1
1.5 Manufacturer's information .............. 1.1
1.5.1 General information................................1.1
1.5.2 Purpose..................................................1.2
1.5.3 Standard delivery scope.........................1.2
1.6 Warranty information,
liability disclaimer............................. 1.2
1.7 Nameplate........................................ 1.2
2 Safety precautions......................... 2.1
2.1 Marking of safety precautions.......... 2.1
2.2 Safety regulations ............................ 2.1
2.3 General safety precautions.............. 2.1
2.3.1 Special symbols .....................................2.2
2.3.2 Information on use of safety
equipment ..............................................2.2
3 Technical Description.................... 3.1
3.1 General overview of NK 100 Screw
Compressor Compact Module
(standard model with electric control
unit).................................................. 3.1
3.2 Flow diagram of NK 100
(electric control unit)......................... 3.2
3.3 Operating description for NK 100
Screw Compressor Compact Module
(electric) ........................................... 3.2
3.3.1 Standstill ................................................3.2
3.3.2 Starting...................................................3.3
3.3.3 Feed phase ............................................3.3
3.3.4 No-load operation ..................................3.3
3.3.5 Start-Stop mode .....................................3.3
3.4 Intake valve for electric control
unit ................................................... 3.4
3.4.1 Installation position ................................3.4
3.5 General overview of NK 100 Screw
Compressor Compact Module
(transmission model with pneumatic
control unit) ...................................... 3.5
3.6 Flow diagram of NK 100
(pneumatic control unit) ................... 3.6
3.7 Operating description for NK 100
Screw Compressor Compact Module
(pneumatic)...................................... 3.6
3.7.1 Standstill ................................................3.6
3.7.2 Starting...................................................3.7
3.7.3 Feed mode.............................................3.7
3.7.4 Stopping ............................................... 3.7
3.7.5 Switching off ......................................... 3.7
3.8 Intake control valve for pneumatic
control unit .......................................3.8
3.8.1 Installation position ............................... 3.8
3.9 Intake air filter ..................................3.9
3.9.1 Micro air filter element .......................... 3.9
3.9.2 Intake filter monitoring .......................... 3.9
3.10 Fine separator ...............................3.10
3.10.1 Oil intake non-return valve.................. 3.10
3.10.2 Fine separator cartridge ..................... 3.11
3.10.3 Minimum pressure valve..................... 3.12
3.11 Air-oil circulation outside
compressor module .......................3.13
3.11.1 Oil filter ............................................... 3.14
3.11.2 Oil thermostat ..................................... 3.14
3.12 Oil cooler/air after-cooler (option) ..3.15
3.13 Safety valve (SIV) (option).............3.15
4 Transport........................................4.1
4.1 Delivery and packing .......................4.1
4.2 Transport damage ...........................4.1
4.3 Transporting unpacked system .......4.2
4.4 Transport options.............................4.2
5 Installation/Assembly....................5.1
5.1 Connection thread/assembly ...........5.1
5.1.1 Fastening screws.................................. 5.1
5.1.2 Pipe connections .................................. 5.1
5.2 Safety precautions for installation
and assembly ..................................5.1
5.3 Installation .......................................5.2
5.3.1 Fastening on base frame with screw
fitting ..................................................... 5.2
5.3.2 Drive ..................................................... 5.2
5.4 Belt drive..........................................5.3
5.5 Direct drive ......................................5.3
5.6 Air outlet ..........................................5.4
5.7 Oil cooling........................................5.4
5.8 Service.............................................5.4
6 Commissioning..............................6.1
6.1 Preparation for commissioning ........6.1
6.2 Checking direction of rotation..........6.1
6.3 Test run ...........................................6.1
6.4 Recommissioning screw
compressor system .........................6.2
7 Maintenance...................................7.1
7.1 Safety precautions...........................7.1
7.2 Oil level............................................7.2

ROTORCOMP VERDICHTER Operating Manual - NK 100
i.2 [en] 09/2008
7.2.1 Oil level check via oil hose (option).......7.2
7.2.2 Oil level check via oil filler opening .......7.2
7.3 Oil change....................................... 7.3
7.3.1 Oil change intervals ..............................7.3
7.3.2 Oil drain point ........................................7.3
7.3.3 Filling with oil.........................................7.4
7.4 Oil filter............................................ 7.4
7.4.1 Oil filter replacement intervals...............7.4
7.4.2 Oil filter replacement .............................7.4
7.5 Fine separator cartridge.................. 7.5
7.5.1 Maintenance intervals ...........................7.5
7.5.2 Replacing fine separator cartridge ........7.5
7.6 Intake air filter ................................. 7.6
7.6.1 Maintenance intervals ...........................7.6
7.6.2 Replacing air filter element....................7.6
7.7 Maintenance check sheet ............... 7.7
7.8 Maintenance intervals..................... 7.8
8 Lubricants and Operating Materials
Maintenance Parts ........................ 8.1
8.1 Lubricants and operating materials. 8.1
8.1.1 Oil recommendation..............................8.1
8.1.2 Topping up oil .......................................8.1
8.1.3 Measures at low room temperature ......8.1
8.1.4 Piping materials ....................................8.1
8.1.5 Pressure dew point of compressed air..8.2
8.1.6 Temperatures........................................8.2
8.1.7 Condensate damage.............................8.2
8.1.8 Cold starts .............................................8.2
8.1.9 Oil separation ........................................8.3
8.1.10 Multigrade oil.........................................8.3
9 Technical Data and
Tightening Torques ...................... 9.1
9.1 Technical data ................................ 9.1
9.2 Tightening torques .......................... 9.2
10 Troubleshooting ......................... 10.1

Operating Manual - NK 100
[en] 09/2008 1.1
1 Foreword
1.1 General
This manual contains information and regulations
for the installation and operation of the NK 100
Screw Compressor Compact Module.
1.2 Scope
This documentation is applicable for the screw
compressor of the type NK 100 Compact Module
from the delivery date of 01/2008.
1.3 Change service
This document is not subject to the change ser-
vice.
1.4 Abbreviations
bar (g) Operating pressure
(relative pressure in bar)
Bh Operating hours
DHV Minimum pressure valve
RC ROTORCOMP
SIV Safety valve
Min. Minimum
Max. Maximum
V DC Direct voltage
V AC Alternating voltage
1.5 Manufacturer's information
1.5.1 General information
This operating manual provides information on the
mode of operation, installation, operation and
maintenance of the NK 100. It is must therefore
always be consulted on the operation and mainte-
nance of the NK 100.
Read this operating manual carefully before com-
missioning the NK 100 for the first time in order to
ensure proper handling, operation and mainte-
nance from the outset.
Pay particular attention to all warnings and safety
precautions.
ROTORCOMP screw compressors are carefully
checked and tested prior to shipping. When your
compressor arrives, the delivery scope must be
checked for completeness and damage.
Any missing parts and/or transport damage must
be reported immediately. A damaged compressor
module must not be put into operation under any
circumstances.
Always have the operating manual available for
the operating personnel and make sure that oper-
ation and maintenance are carried out according
to the instructions.
All instructions contained in this operating manual
must be observed in the specified manner and
sequence in order to prevent injuries and damage
to the system.
The screw compressor has been built according to
the latest technology and the recognized safety
rules.
Danger may nevertheless result for the user or
others or for the compressor system during its
use.
Any use other than described in the chapter "Pur-
pose" is considered improper.
ROTORCOMP shall not be liable for any damage
or injuries resulting from such improper use.
We shall not provide any guarantee whatsoever
for malfunctions and damage resulting from failure
to comply with the operating manual.
The manufacturer reserves the right to carry out
further technical developments without prior
notice.
Always specify the model and the complete serial
number from the nameplate in all correspondence.
ROTORCOMP shall assume no liability whatso-
ever for damage or injuries which occur during
handling, operation, maintenance work or repairs
due to a failure to comply with the safety instruc-
tions to proceed with the usual care and caution,
even if this is not expressly mentioned in this oper-
ating manual.

ROTORCOMP VERDICHTER Operating Manual - NK 100
1.2 [en] 09/2008
1.5.2 Purpose
The NK 100 is a screw compressor compact mod-
ule designed for installation in a compressed-air
generating station.
The sole intended use of the system is the com-
pression of atmospheric air. The NK 100 may only
be used to compress gases or other media follow-
ing written approval by ROTORCOMP.
The NK 100 may only be installed by specialized
companies with the corresponding know-how.
The safety precautions, technical data, limits,
installation guidelines and regulations for commis-
sioning and operation specified in this operating
manual must be observed and complied with.
1.5.3 Standard delivery scope
With the NK 100, ROTORCOMP offers a com-
pletely equipped, compact compressor module.
The components of the standard delivery scope
are described in the following chapters.
Optionally available components are marked with
(optional).
1.6 Warranty information,
liability disclaimer
ROTORCOMP is a manufacturer of screw com-
pressor components and not of ready-to-operate
compressor systems.
RC shall only be answerable for any defects of
these individual components for which it is respon-
sible within the scope of the warranty conditions.
Failure to comply with the following instructions
and information shall void any and all liability. This
liability disclaimer also results in the loss of claims
for damages. This applies in particular in case of:
– Installation not approved by RC
– Improper use
– Operation of the compressor outside the spec-
ified limits
– Failure to observe the safety precautions and
the usual care and caution
– Unsuitable operating materials (gases, oils)
– Condensate in the screw compressor
– Corrosion as subsequent damage
– Improper operation
– Insufficient maintenance, missing proof of
maintenance
– Use of unsuitable tools
– Failure to use genuine spare parts
– Unauthorized modifications to the screw com-
pressor module and/or its components
1.7 Nameplate
For the location of the nameplate, see Figure 3-1
and 3-5.
Should you have questions, please provide us
with the data on the nameplate. This ensures that
you receive the correct information.
Figure 1-1
Stamping for customers outside Germany
(Europe)
1. Order No.
2. Model
3. Serial No.
4. Year of manufacture
5. Max. rpm
6. Max. operating pressure in psi
7. Max. operating temperature °F
8. Max. operating temperature °C
9. Max. operating pressure in bar
1 2 3 4
7
6
5
9 8

Operating Manual - NK 100
[en] 09/2008 2.1
2 Safety precautions
2.1 Marking of safety precautions
Important instructions concerning hazards to per-
sons, technical safety and their operational safety
are especially highlighted in the following.
They precede the measures to be taken and have
the following meaning:
d Warning:
Indicates working and operating processes which
must be exactly complied with in order to prevent
endangering of persons. These include informa-
tion on special dangers when handling the system.
e Caution:
Refers to working and operating processes which
must be exactly complied with to prevent damage
to or destruction of parts or all of the system.
L Note:
Indicates special information for better handling
during operating, inspection and adjustment pro-
cesses and care work.
2.2 Safety regulations
The regulations of the respective country for put-
ting into service and operating pressure vessels
must be observed. In Germany these include:
– Directive 97/23/EC (Pressure Vessel Directive
DGRL) of 05/29/1997
– Operating Safety Ordinance (BetrSichV)
of 09/27/2002
2.3 General safety precautions
This operating manual contains important instruc-
tions and information on the installation, commis-
sioning, operation and maintenance, which must
be observed by the owner. As a result, it is abso-
lutely necessary to turn over the entire documen-
tation to the specially trained personnel of the
owner or to make it available at the operating loca-
tion prior to installation and commissioning. Prior
to installation and commissioning, the entire oper-
ating manual must be carefully read by the spe-
cially trained personnel and then kept in a safe
place. Failure to observe the safety precautions
can result in a serious hazard for the personnel,
the pressure vessel or the environment.
Observe the chapter "Manufacturer's information"
on page 1-1 of this operating manual.
The following safety precautions only refer to the
NK 100 screw compressor module and not to the
entire compressor system.
The applicable national safety and occupational
safety regulations of the respective country in
which the system is operated must be complied
with.
The manufacturer of the compressor system is
responsible for including the necessary safety reg-
ulations for the operation of the compressor sys-
tem in the operating manual of the compressor
system.
Installation, operation, maintenance and repair
may only be carried out by authorized, trained and
qualified personnel.
The operating personnel is expected to safely use
the working technology and follow all applicable
local operating safety regulations and provisions.
The owner bears the responsibility for always
keeping the machine in safe operating condition.
Limits (pressures, temperatures, time settings,
etc.) must be permanently marked.
Should a regulation contained in this list, espe-
cially with regard to safety, not comply with legal
regulations, then the safer of the two applies.

ROTORCOMP VERDICHTER Operating Manual - NK 100
2.2 [en] 09/2008
2.3.1 Special symbols
Do not operate the system without the
safety device mounted
Do not inhale compressed air from this
machine
Warning:
System can be started automatically via
remote control following a power failure
Warning:
System runs on for 30 seconds after the
"OFF" button is pressed
Watch cooling air
Warning:
Do not operate with doors open or
shrouding loose
Warning:
Hot machine parts
Warning:
Pressurized part or system
Lifting point
Warning:
High voltage
Active environmental protection
Warning on a danger point
Warning:
Danger of explosion and/or detonation
Warning:
Hazardous substances
Warning:
Flammable substances
2.3.2 Information on use of safety
equipment
Wear safety helmet
Wear safety shoes
Wear personal safety equipment
(safety goggles, protective gloves, safety
clothing, etc.) in accordance with the local
safety regulations
Read the operating manual before
commissioning, maintenance, service
and repairs.

Operating Manual - NK 100
[en] 09/2008 3.1
3 Technical Description
3.1 General overview of NK 100 Screw Compressor Compact Module
(standard model with electric control unit)
Figure 3-1
1. Air-oil separating element
2. Intake valve with air filter
3. Maintenance indicator for intake filter (optional)
4. Control unit, electric
5. Transport eye
6. Oil filler opening
7. Oil level monitoring (optional)
8. Oil drain screw
9. Oil separation return line with oil-extraction sight glass (optional)
10. Oil filter
11. Oil circulation/On
12. Oil circulation/Off
13. Minimum pressure valve
14. Compressed air outlet
15. Separator head
16. Safety valve (optional)
17. Temperature sensor connection (optional)
18. Nameplate
19. NK 100 basic module
20. Drive shaft
21. End cover
3
8
6
7
20
19
21
21
5
1011121318 1415 917 16
4

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.2 [en] 09/2008
3.2 Flow diagram of NK 100
(electric control unit)
Figure 3-2
1. Intake filter
2. Intake valve
2.1 No-load nozzle
3. Control unit (electric)
3.1 Discharge delay valve (EVV)
3.2 Solenoid valve
4. Screw compressor
5. Separator tank with pre-separation
6. Fine separator
7. Minimum pressure valve
8. Oil thermostat
9. Oil filter
10. Oil cooler
11. Air after-cooler
12. Non-return valve
13 Safety valve (optional)
14. Non-return valve
3.3 Operating description for NK 100
Screw Compressor Compact Module
(electric)
The flow diagram shows a schematic view of the
operating principle and the arrangement of the
main components of the NK 100 screw compres-
sor module with electrical control unit, regardless
of any other equipment.
3.3.1 Standstill
At standstill the solenoid valve 3.2 is deenergized
and the downstream devices are depressurized.
The minimum pressure valve 7set to approx.
5.5 bar at the factory is tightly closed. The intake
valve 2is closed at standstill.
2.1
3
711
1
2
8
10
9
45
3.2
13
6
12
3.1
14

Operating Manual - NK 100
[en] 09/2008 3.3
3.3.2 Starting
When starting the compressor, the solenoid valve
of the control unit is energized. The intake valve 2
is closed by the spring 3-3/4. The rotors of the
screw compressor 4suck in air via the bypass
hole and the non-return valve 14. This air is com-
pressed. The pressure slowly increases in the
separator tank 5. The compressed air is routed
over the control piston 3-3/3 of the intake valve via
the control unit 3. This opens the intake valve and
the air can flow through the intake valve into the
compression chamber.
3.3.3 Feed phase
During the feed phase the air drawn in flows via
the intake filter 1through the intake valve 2
directly into the compression chamber of the
screw compressor 4. There the intake air is com-
pressed and oil for lubrication and cooling is
injected.
The oil-air mixture then enters the separator
tank 5in which the majority of the oil is separated
from the air. The air then flows via the fine separa-
tor 6and the minimum pressure valve 7to the
compressed air outlet.
In the fine separator 6the oil is filtered out down to
a residual content of < 3 mg/m
3
and then routed
back into the compressor housing via a nozzle and
a non-return valve 12.
When the compressor is switched off, the mini-
mum pressure valve 7with a non-return function
prevents backflow of the compressed air out of the
system into the compression chamber in the dis-
charge phase.
During startup a faster pressure buildup is also
ensured, which is required for optimum lubrication
and oil separation.
The heat resulting during compression is dissi-
pated via the oil-air mixture. The oil circulation also
results from the pressure difference between the
outlet and inlet pressure. The optimum operating
temperature for the oil is adjusted by the oil ther-
mostat 8. Depending on the oil temperature, the oil
flow is routed directly via the oil cooler 10 or
directly to the oil filter 9by the oil thermostat valve.
The oil then flows via the oil filter 9to the various
injection points in the compressor block.
3.3.4 No-load operation
When the final pressure in the storage tank is
reached, the solenoid valve 3.1 is deenergized by
a pressure switch. As a result, the compressed air
over the control piston 3-3/3 of the intake valve is
discharged into the atmosphere by the solenoid
valve and the spring 3-5/4 closes the valve plate of
the intake valve. With the deenergized solenoid
valve, the discharging of the separator tank is also
initiated via a piston in the control unit. When the
final pressure is reached, the run-on time is
started via a pressure switch.
In the run-on time the separator tank is discharged
to a residual pressure of approx. 1.5 bar. If the
pressure in the storage tank reaches the lower
switch-on pressure in the run-on time, the solenoid
valve is energized again via pressure switches.
This stops the discharging of the separator tank
and the intake valve opens again.
If the lower switch-on pressure is not reached in
the run-on time, the system is stopped and the
separator tank is completely discharged.
When the lower switch-on pressure is reached,
the system starts up again automatically.
3.3.5 Start-Stop mode
When the final pressure is reached in the storage
tank, the system is switched off with pressure
switches. The compressed air over the control
piston 3-3/3 of the intake valve is discharged into
the atmosphere via the solenoid valve. As a result,
the spring 3-3/4 closes the valve plate of the
intake valve.
With the now deenergized solenoid valve, the dis-
charging of the separator tank is initiated via pis-
tons in the control unit. Discharging is carried out
via the discharge delay valve (EVV) 3.1. Quick
discharging down to approx. 2 bar is carried out
via a non-return valve. At 2 bar the non-return
valve closes and the remaining discharging is car-
ried out via a small nozzle. This prevents the oil
from foaming.

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.4 [en] 09/2008
3.4 Intake valve for electric control unit
The NK 100 is equipped with an integrated intake
valve mounted directly on the compressor hous-
ing.
Figure 3-3
AIntake valve opened
BIntake valve closed
1. Air inlet
2. Air outlet
3. Control piston
4. Spring
3.4.1 Installation position
Figure 3-4
AB
11
2
3
4

Operating Manual - NK 100
[en] 09/2008 3.5
3.5 General overview of NK 100 Screw Compressor Compact Module
(transmission model with pneumatic control unit S3T)
Figure 3-5
1. Air-oil separating element
2. Air filter
3. Maintenance indicator for intake filter (optional)
4. Control unit, pneumatic
5. Transport eye
6. Oil filler opening
7. Oil level monitoring (optional)
8. Oil drain screw
9. Oil separation return line with oil-extraction sight glass (optional)
10. Oil filter
11. Oil circulation/On
12. Oil circulation/Off
13. Minimum pressure valve
14. Compressed air outlet
15. Separator head
16. Safety valve (optional)
17. Temperature sensor connection (optional)
18. Nameplate
19. NK 100 basic module
20. Transmission
21. Drive shaft
22. Intake control valve
22
21 9 10
11
121314151617181920
3
8
4
5
6
7
1 2

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.6 [en] 09/2008
3.6 Flow diagram of NK 100
(pneumatic control unit S3T)
Figure 3-6
1. Intake filter
2. Intake control valve
2.1 Nozzle
3. Control unit (pneumatic)
3.1 Proportional control valve (positive)
3.2 Impulse-pressure relief valve
4. Screw compressor
5. Separator tank with pre-separation
6. Fine separator
7. Minimum pressure valve
8. Oil thermostat
9. Oil filter
10. Oil cooler
11. Air after-cooler
12. Non-return valve
13 Safety valve (optional)
3.7 Operating description for NK 100
Screw Compressor Compact Module
(pneumatic)
The flow diagram shows a schematic view of the
operating principle and the arrangement of the
main components of the NK 100 screw compres-
sor module with pneumatic control unit, regardless
of any other equipment.
3.7.1 Standstill
At standstill the intake control valve 2is closed by
the spring 3-7/3. The downstream devices up to
minimum pressure valve 7are depressurized. The
minimum pressure valve is set to approx. 5.5 bar
at the factory is tightly closed. The proportional
control valve 3.1 is set to operating pressure.
2.1
1
2
8
10
9
45
13
6
7
11
12
3.1
3.2
3

Operating Manual - NK 100
[en] 09/2008 3.7
3.7.2 Starting
In the startup phase the intake control valve is
closed via the spring 3-7/3. The rotors in the screw
compressor 4intake air via a bypass hole with a
non-return valve in the intake control valve and
relief valve.
This air is compressed and the pressure in the
separator slowly increases. This pressure is
routed via the control unit 3before the holding pis-
ton 3-7/6. This presses the holding piston toward
the rear and the control piston 3-7/4 opens the
intake control valve with the spring.
The desired final pressure can be set on the pro-
portional control valve 3.1.
When the set final pressure is almost reached,
the proportional control valve 3.1 opens and com-
pressed air is routed behind the control pis-
ton 3-7/4. As a result, the control piston is pressed
toward the front and the valve plate 3-7/5 closes
the intake control valve. If the operating pressure
drops, the proportional control valve closes and
the intake control valve opens again. The propor-
tional control valve steplessly controls the opening
of the intake control valve depending on the oper-
ating pressure.
3.7.3 Feed mode
The air drawn in flows via the intake filter 1
through the intake control valve 2directly into the
compression chamber of the screw compressor 4.
There the intake air is compressed and oil for lubri-
cation and cooling is injected.
The oil-air mixture then enters the separator
tank 5in which the majority of the oil is separated
from the air.
The air then flows via the fine separator 6and the
minimum pressure valve 7to the compressed air
outlet.
In the fine separator 6the oil is filtered out down to
a residual content of < 3 mg/m
3
and then routed
back into the compressor housing via a nozzle and
a non-return valve 12.
When the compressor is switched off, the mini-
mum pressure valve 7with a non-return function
prevents backflow of the compressed air out of the
system into the compression chamber in the dis-
charge phase.
During startup a faster pressure buildup is also
ensured, which is required for optimum lubrication
and oil separation.
The heat resulting during compression is dissi-
pated via the oil-air mixture. The oil circulation also
results from the pressure difference between the
outlet and inlet pressure. The optimum operating
temperature for the oil is adjusted by the oil ther-
mostat 8. Depending on the oil temperature, the oil
flow is routed directly via the oil cooler 10 or
directly to the oil filter 9by the thermostat valve.
The oil then flows via the oil filter 9to the various
injection points in the compressor block.
3.7.4 Stopping
When switching off the system, the valve
plate 3-7/5 closes the intake control valve immedi-
ately with the spring 3-7/8. This causes pressure
to build up in the intake chamber. This pressure
actuates a piston in the relief valve 3.2 and the
separator is discharged via holes in the relief valve
and intake control valves in the intake filter 1.
3.7.5 Switching off
When switching off the system, the intake control
valve 2operates, supported by spring pressure,
as an independent non-return valve and closes
the intake opening oil-tight.

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.8 [en] 09/2008
3.8 Intake control valve for pneumatic
control unit
The NK 100 is equipped with an integrated intake
control valve mounted directly on the compressor
housing.
Figure 3-7
AIntake valve closed
BIntake valve opened
1. Air inlet
2. Air outlet
3. Spring of holding piston
4. Control piston
5. Valve plate
6. Holding piston
7. Spring of control piston
8. Spring of valve plate
3.8.1 Installation position
Figure 3-8
1. Impulse-pressure relief valve
2. Proportional control valve
3. Intake control valve
AB
1
1
2
34
5678
1
23

Operating Manual - NK 100
[en] 09/2008 3.9
3.9 Intake air filter
Figure 3-9
3.9.1 Micro air filter element
The RC intake air filter is mounted directly over the
intake valve.
The micro air filter 1with a fineness of 10 µm is
used for the filtering of intake air.
The constant degree of separation of almost 100%
on all loading levels, the resistance to heat, cold,
water, oil and fuel and a large filter area permit a
long service life. As a result, the air filter element
is the ideal fine filter for the filtering of intake air of
compressor system.
3.9.2 Intake filter monitoring
• Maintenance indicator, optical (option)
• Maintenance indicator, electric (option)
The micro dry filter cartridges are recommended
as a 1-stage filter with a low filter resistance for
standard applications.
e Caution:
Special applications, e.g. system installation in a
heavily soiled environment, mobile systems, etc.,
require 2-stage filters with a somewhat higher filter
resistance, however a better degree of separation
for the protection of the compressor system.
Filter Type/Order No.: on special request.
1

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.10 [en] 09/2008
3.10 Fine separator
Figure 3-10
1. Fine separator cartridge
2. Oil separation return line with oil-extraction
sight glass (option)
3. Minimum pressure valve
3.10.1 Oil intake non-return valve
Figure 3-11
The oil intake non-return valve 1prevents flooding
of the fine separator cartridge with oil flowing back
out of the screw compressor due to the pressure
difference in the system when the screw compres-
sor system is switched off.
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1

Operating Manual - NK 100
[en] 09/2008 3.11
3.10.2 Fine separator cartridge
Figure 3-12
1. De-oiled compressed air
2. Post-separator
3. Fine separator
4. Pressure-resistant support pipe
5. Separated oil
6. Outlet of de-oiled air
7. Inlet of air-oil mixture
8. Sealing off
9. Pressure-resistant housing
The fine separator cartridge is used to recover the
extremely finely distributed residual oil in the form
of droplets following the pre-separation.
The fine separator cartridge separates virtually the
entire residual oil from the compressed air. An
optimum pre-separation in the separating tank is
assumed - the better the pre-separation, the better
the fine separation.
The vertical cartridge is flowed against from
below, while the residual oil is separated out while
flowing through the special filter element. Then it
is fed into the oil circulation again.
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9

ROTORCOMP VERDICHTER Operating Manual - NK 100
3.12 [en] 09/2008
3.10.3 Minimum pressure valve
Figure 3-13
1. Non-return valve plate
2. Non-return valve spring
3. O-ring
4. Pressure holding valve piston
5. Pressure holding valve spring
6. Pressure holding valve housing
AMinimum pressure valve closed
BMinimum pressure valve opened
The minimum pressure valve is located on the out-
let of the compressor before the air recooler and
serves as:
a) Pressure holding valve
It prevents the pressure drop, in case of a lack of
counter-pressure, under a minimum pressure of
approx. 5.5 bar. This pressure is necessary to
ensure the oil supply of the compressor. At the
same time this is the condition for good oil separa-
tion.
b) Non-return valve
It prevents compressed air from flowing back out
of the system or the compressed-air reservoir into
the screw compressor system. As a result, the
system can be completely discharged when the
separator reservoir is switched off.
This valve operates automatically.
AB
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