Fluke PG7607 User manual

© 2010 Fluke Calibration
PG7607
Piston Gauge
Operation and Maintenance Manual
(Use with PG7000 Operation
and Maintenance Manual)

© 2010 Fluke Calibration Page II
Warning
High pressure liquids and gases are potentially hazardous. Energy stored in these
liquids and gases can be released unexpectedly and with extreme force. High
pressure systems should be assembled and operated only by personnel who have
been instructed in proper safety practices.
©2010 Fluke Calibration All rights reserved.
Information in this document is subject to change without notice. No part of this document may be reproduced or transmitted in any
form or by any means, electronic or mechanical, for any purpose, without the express written permission of Fluke Calibration,
4765 East Beautiful Lane, Phoenix, Arizona 85044-5318 USA.
Fluke Calibration makes sincere efforts to ensure the accuracy and quality of its published materials; however, no warranty,
expressed or implied, is provided. Fluke Calibration disclaims any responsibility or liability for any direct or indirect damages
resulting from the use of the information in this manual or products described in it. Mention of any product or brand does not
constitute an endorsement by Fluke Calibration of that product or brand. This manual was originally composed in English and
was subsequently translated into other languages. The fidelity of the translation cannot be guaranteed. In case of conflict between
the English version and other language versions, the English version predominates.
Products described in this manual are manufactured under international patents and one or more of the following U.S. patents:
6,701,791, 5,142,483, 5,257,640, 5,331,838, 5,445,035. Other U.S. and international patents pending.
Fluke Calibration,FCAL, DH,DHI, PG7000, PG7607, PG7102, PG7202, PG7302, PG7601, COMPASS, CalTool are trademarks,
registered and otherwise, of Fluke Corporation.
Swagelok is a registered trademark of the Swagelok Company
Krytox and Viton are trademarks of the Dupont de Nemours Company
Document No. 3152174
101215
Printed in the USA.

Page III © 2010 Fluke Calibration
Table Of Contents
Table Of Contents ................................................................ III
Tables ................................................................................. IV
Figures................................................................................ IV
About This Manual..................................................................v
1. Introduction .....................................................................1
1.1 Product Overview...................................................................................................................................1
1.2 Specifications.........................................................................................................................................2
1.2.1 General Specifications ............................................................................................................................ 2
1.2.2 Piston-Cylinder Assembly....................................................................................................................... 2
1.2.3 Pressure Measurements.......................................................................................................................... 2
2. Installation.......................................................................3
2.1 Unpacking and Inspection.....................................................................................................................3
2.1.1 Removing From Packaging..................................................................................................................... 3
2.1.1.1 Piston-Cylinder Assembly ...................................................................................................................... 3
2.1.2 Inspecting Contents................................................................................................................................. 4
2.1.2.1 PG7607 Platform ................................................................................................................................... 4
2.1.2.2 Piston-Cylinder Assembly ...................................................................................................................... 5
2.2 Initial Setup.............................................................................................................................................5
2.2.1 CCP Pressure Connection....................................................................................................................... 5
2.2.2 Installing and Removing the Piston-Cylinder Assembly....................................................................... 5
3. Operation.........................................................................9
3.1 Controlled Clearance Pressure (CCP)..................................................................................................9
3.2 [HEAD].....................................................................................................................................................9
4. Maintenance, Adjustments and Calibration .......................11
4.1 Piston-Cylinder Assembly and Disassembly.....................................................................................11
4.2 Cleaning Piston-Cylinders...................................................................................................................12
4.3 Piston-Cylinder Recalibration .............................................................................................................12
4.3.1 Mass of the Cylinder.............................................................................................................................. 12
4.4 Disassembly of Piston Retaining Assembly......................................................................................12
4.4.1 Disassembly Procedure......................................................................................................................... 13
4.4.2 Reassembly Procedure.......................................................................................................................... 14
5. Troubleshooting .............................................................15
5.1 Overview ...............................................................................................................................................15

TABLES AND FIGURES
© 2010 Fluke Calibration Page IV
Tables
Table 1. PG7607 Parts List..........................................................................................................................4
Table 2. 50 mm Gas Piston-Cylinder Assembly Parts List...........................................................................5
Table 3. PG7607 Troubleshooting Checklist..............................................................................................15
Figures
Figure 1. Piston-Cylinder Installation............................................................................................................7
Figure 2. Piston Retainer Assembly...........................................................................................................13

Page v © 2010 Fluke Calibration
About This Manual
This manual is designed to be used in conjunction with the PG7000 Piston Gauges Operation and
Maintenance Manual, to operate a PG7607 Piston Gauge.
PG7607 is identical in conception and features to a PG7601 piston gauge. PG7607 differs only in the piston-
cylinder mounting post and the piston-cylinder module as PG7607 is designed to exploit a unique 50 mm
diameter piston-cylinder. This manual covers the aspects of PG7607 that are different from PG7601.
To operate a PG7607, use the PG7000 Piston Gauges Operation and Maintenance Manual and follow the
instructions and information applying to PG7601. Refer to this manual for details on the piston-cylinder
mounting post and piston-cylinder module.
Note
In PG7607, the CYLINDER rather than the PISTON floats and is rotated. When
using the PG7000 Manual to operate PG7607, references to the PISTON of PG7601
apply to the CYLINDER of PG7607.
Manual Conventions
Caution
“Caution” is used in throughout the manual to identify conditions or actions that
could cause harm to the PG7607 or to the devices that are connected to it.
Warning
“Warning” is used in throughout the manual to identify actions that could pose a
hazard to the user of the PG7607.
Note
“Note” is used throughout the manual to identify operating and applications advice
and additional explanations.
[ ] Indicates direct function keys (e.g., [RANGE]).
< > Indicates molbox1+ screen displays (e.g., <1yes>).

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page vi
Notes

Page 1 © 2010 Fluke Calibration
1. Introduction
1.1 Product Overview
PG7607 is a special model in the PG7000 line of piston gauges. PG7607 is identical to PG7601 except
for its piston-cylinder and mounting post.
PG7607 was designed to exploit a unique 50 mm diameter piston-cylinder. With this piston-cylinder, the
piston is mounted in a fixed position in the mounting post and the cylinder floats and is rotated.
A controlled clearance pressure can be introduced into the mounting post allowing the piston diameter and
thus the gap between the piston and cylinder to be varied.
PG7607 is available on a limited basis and, generally, is only offered for use in national measurement
institutes or other laboratories performing fundamental research in pressure metrology.
Note
This manual is intended to be used as a supplement to the PG7000 Manual.
PG7607 is identical to PG7601 except for its piston-cylinder and mounting post. To
operate a PG7607, use a PG7000 Operation and Maintenance Manual and apply the
information on PG7601 referring to this manual for piston-cylinder and mounting
post information. Also keep in mind that in PG7607, the CYLINDER, rather than the
PISTON, floats and is rotated. References to the PG7601 PISTON in the PG7000
Manual apply to the CYLINDER of PG7607.

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 2
1.2 Specifications
1.2.1 General Specifications
Specifications below are specific to PG7607. All other specifications are identical to PG7000
specifications found in the PG7000 Operation and Maintenance Manual (P/N 3152117).
Weight
Instrument platform with no
mass loaded.
17 kg (29 lb)
Overall Pressure Ranges
with 35 kg mass set
Gauge: 5 to 175 kPa (0.7 to 25.4 psi)
Absolute: 5 to 175 kPa (0.7 to 25.4 psi)
Operating Medium
Clean, dry, non-corrosive gas
Maximum Mass Load
35 kg (38 kg with AMH automated mass handler)
Pressure Connections
TEST Port
Bell Jar Vent Port
Piston Controlled Clearance
Pressure (CCP)
Vacuum Reference Ports
CE Conformance
DH200
DH200
DH200
NOTE: DH200 is a gland and collar type fittings for 1/4 in.
(6 mm) coned and left hand threaded tubes equivalent to
AE SF250C, HIP LF4, etc.
KF25 on platform and bell jar (KF40 available on optional
AMH automated mass handler)
Available, must be specified.
1.2.2 Piston-Cylinder Assembly
The piston is mounted in a fixed position on the mounting post. The cylinder floats and
is rotated.
Piston Material:
Tungsten carbide
Cylinder Material:
Tungsten carbide
Nominal Diameter:
50 mm
Nominal Area:
2 000 mm2
Mounting System:
Free deformation with controlled clearance pressure
(CCP) available on inside of piston.
Typical Drop Rate:
Full mass load
< 0.1 mm/min
1.2.3 Pressure Measurements
The piston is mounted in a fixed position on the mounting post. The cylinder floats and
is rotated.
Sensitivity1:
0.01 Pa + 0.5 ppm
Reproducibility2:
± 2 ppm
1 Sensitivity: The smallest variation in input detectable in output.
2 Reproducibility: Combined long term stability of piston-cylinder effective area and masses.

Page 3 © 2010 Fluke Calibration
2. Installation
2.1 Unpacking and Inspection
2.1.1 Removing From Packaging
PG7607 is delivered (along with its standard accessories) in a reusable molded transit case
with polyurethane inserts to hold it in place.
Remove the PG7607 and its accessories from the shipping container and remove each
element from its protective plastic bag.
2.1.1.1 Piston-Cylinder Assembly
The piston-cylinder assembly is shipped in a molded plastic case with custom
polyethylene inserts that accommodates 2 Acetal bullet cases. The piston and
the cylinder are separate; each is packed in its own bullet case. Do not handle
either of these elements with your bare hands. Use the gloves that are in the
PG7607 accessory kit or use the lint free wipes.
Caution
Never handle the piston or cylinder with bare hands. Oil and
acids from bare skin can damage the critical surfaces (polished
appearance).

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 4
2.1.2 Inspecting Contents
Check that all items are present and have NO visible damage.
2.1.2.1 PG7607 Platform
Table 1. PG7607 Parts List
PG7607
#3069845
MOTORIZED ROTATION
NON-CE
PG7607
#3072356
MOTORIZED ROTATION
CE
Platform 3118270 3118296
Mass Bell 3071603
Bell Jar W/KF16 3070377
Terminal 3069735
PG Terminal to Platform Cable
Non-CE (DB25M - DB25F, ≈1.8 meters) 3068724
CE (DB25M - DB25F, ≈1.5 meters) 3072235
Power Cable 3133781 3153005
Accessory Kit 401049
Cable, null modem (for flashing) 3077370
(2) NIP, SS, DH200, 2.75" 3068377
(2) ADPT, SS, DH200 F X 1/8 in. NPT F 3068547
(2) O-ring, Viton, brown, 2-029 3144730
O-ring, Viton, brown, 2-019 3134945
(2) O-ring, Buna, 2-242 3135041
Cover, storage, 7600 type 3135594
Allen wrench, 2.5 mm 3136044
Allen wrench, 3 mm 3135703
Allen wrench, 5 mm 3136098
KrytoxGPL205/6 0.5 oz 2493420
Gift kit with gloves 3123777
ADPT, DH200 M X 1/8 in. swage 3069062
Valve, vacuum relief 3124573
Documentation
Calibration Report (PG)
Calibration Report (Mass Bell)
Technical Data
Manuals
Documentation CD
3152121
3152121
3152139
3152117 (PG7000)
3152174 (PG7607)
3139043

2. INSTALLATION
Page 5 © 2010 Fluke Calibration
2.1.2.2 Piston-Cylinder Assembly
Table 2. 50 mm Gas Piston-Cylinder Assembly Parts List
5 KPA/KG
PC-7607-TC
Piston-cylinder kit 3069892
Piston-cylinder 3118415
Piston-cylinder case (w/ 2 bullet
cases) 3121645
Accessory Kit 3118500
(2) O-rings, brown, Viton (2-015) 3134923
Documentation
Calibration report
3152121
2.2 Initial Setup
2.2.1 CCP Pressure Connection
The pressure connection labeled CCP is for the application of a controlled clearance pressure
to the inside of the piston (see Section 3.1). In normal operation, the measured pressure is
applied to the CCP pressure connection. Use a tee to connect the TEST port and the CCP
port together.
2.2.2 Installing and Removing the Piston-Cylinder
Assembly
Note
Unlike other PG7000 models, the PG7607 piston-cylinder and mounting
elements are not an integrated module. The piston and cylinder are
delivered and installed as separate parts.
Caution
Given the large diameter and small annular gap of the PG7607 piston-
cylinders, it is very difficult to insert the piston into the cylinder without the
aid of the alignment mechanism provided by the PG7607 platform
mounting post and piston retaining assembly. There is a risk of cocking
the piston in the cylinder. It is not recommended that the piston ever be put
into the cylinder when the piston is not installed on the PG7607 mounting
post.
To operate the PG7607 platform, a piston-cylinder must be installed on its mounting post. To install
a piston-cylinder assembly on the PG7607 platform, follow the sequential procedure below. This
procedure may be used on the first and subsequent piston-cylinder installations; it may also be
used in reverse order to remove a piston-cylinder. Numerical references in the procedure refer to
Figure 1.

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 6
Remove the piston retaining assembly (5). The PG7607 platform is delivered with the
piston retaining assembly (5) installed in the mounting post (7). Holding the piston
retaining assembly by the knurled surface (14), unscrew it (rotate CCW) fully from the
mounting post and remove it. Avoid touching the WHITE cylinder centering ring (15) as it
will eventually contact the critical inside surface of the cylinder.
Check that the lower piston sealing O-ring (10a) is installed. The PG7607 platform is
delivered with the lower and upper piston sealing O-rings (10a, 10b) and O-ring carriers
installed loosely in the recess on the mounting post. Remove the upper O-ring and O-
ring carrier (10b) and retain. Check that the lower O-ring and O-ring carrier (10a) are
present and properly seated. (If needed two spare o-rings are included in the PG7607
platform accessory kit).
Remove the piston (6) from its packing. Using lint free gloves or wipes to avoid direct
contact with the piston critical surface (polished appearance) remove the piston (6) from
its packing.
Caution
Never handle the piston or cylinder with bare hands. Oil and acids from
bare skin can damage the critical surfaces (polished appearance). The
cylinder is part of the mass load and contamination can change its mass.
Install the piston (6) on the mounting post (7). With the end of the piston etched with “X”
and/or the serial number UP (11) so that it will enter the cylinder first, slip the piston over the
mounting post and slide it down until it seats on O-ring (10a.) Check that the end of the piston
facing UP has “X” and/or the serial number marked on it.
Install the piston retaining assembly (5). Place the upper O-ring and carrier (10a) centered
on the top surface of the piston. Hold the piston retaining assembly (5) by the knurled ring (14);
avoid touching the white cylinder centering ring (15) as it will eventually contact the critical
inside surface of the cylinder. Thread the piston retaining assembly into the top of the
mounting post (7) and screw it down carefully assuring that upper O-ring carrier (10a) is not
pinched. The assembly’s shoulder (13) should meet the top of the piston (11) with no gap
between the two surfaces. There will be some resistance from the mounting post O-ring (12),
only hand tightening is needed. Do not use tools to install the piston retaining assembly.
Tighten lightly by hand until the assembly reaches the end of the engagement threads and
surfaces (13) and (11) meet.
Clean the piston (6) and the cylinder centering ring (15), consider cleaning the
cylinder (4). Using the glass cleaner method described in Section 4.2, clean the
piston (6) and the cylinder centering ring (15). If this is the first piston-cylinder installation,
also clean the cylinder (4). On subsequent installations consider cleaning the cylinder
before installing it.
Verify that the cylinder cap O-ring (3) is properly installed. Remove the cylinder (4) from
its packing. It is delivered with the cylinder cap O-ring (3) installed. Check that the O-ring is
present and properly seated. If not, install one (an extra one is included in the piston-cylinder
accessories). Use tweezers or another long narrow tool. DO NOT touch the inside of the
cylinder.
Verify that the cylinder adjustment mass (17) is properly installed. Check that the
cylinder adjusting mass (17) is present and completely threaded onto the cylinder
retaining screw (2). This mass is used to adjust the total cylinder mass to the value
reported in the calibration report.
Install the cylinder (4) on the piston (6). Gently slip the cylinder (4) over the piston (6).
The cylinder centering ring (15) aligns the cylinder on the piston facilitating the
insertion process. Allow the cylinder to slip all the way down the piston until it reaches
end of stroke.

2. INSTALLATION
Page 7 © 2010 Fluke Calibration
Tighten the cylinder retaining screw (2). Using a 5 mm Allen tool (one is supplied in
the PG7607 accessories), tighten the cylinder retaining screw (2) into the cylinder stroke
limiter (16) of the piston retaining assembly (5). Turn the screw CW to tighten. Since the
cylinder stroke limiter (16) is free to move within the piston retaining assembly (5), the
retaining screw (2) may rotate with the assembly, failing to tighten. If this is the case,
press down a bit or lift up on the screw to help it engage and tighten. Tighten gently until
you can feel the cylinder cap O-ring (3) takes its seat in the cylinder stroke limiter.
Caution
Be sure the cylinder retaining screw (2) is tightened before applying
pressure to the piston-cylinder. The cylinder stroke limiter (16) limits the
cylinder’s upward movement preventing it from coming off the piston.
Figure 1. Piston-Cylinder Installation
 Cylinder Cap
Cylinder Retaining Screw
Cylinder Cap O-ring (Brown, Viton, 2-015)
Cylinder
 Piston Retainer Assembly/Nut
Piston
Mounting Post (part of PG7607 platform)
Controlled Clearance Pressure (CCP) Inlet
Test Pressure Inlet
a.Piston Sealing O-ring – lower
(Brown Viton, 2-029)
b.Piston Sealing O-ring – upper
(Brown Viton, 2-029)
Piston Top Surface
Mounting Post O-ring (Brown, Viton, 2-019)
Piston Retainer Assembly Shoulder
Knurled Gripping Holding Surface
Cylinder Centering Ring
Cylinder Stroke Limiter
Adjustment Mass

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 8
Notes

Page 9 © 2010 Fluke Calibration
3. Operation
3.1 Controlled Clearance Pressure (CCP)
Note
In normal operation, the CCP pressure is the measured pressure. The pressure
applied to the TEST port should also be applied to the CCP port.
PG7607 allows an independent pressure to be applied to the inside of the piston. The purpose of this feature is
to allow the piston to be artificially expanded, varying the size of the gap between the piston and cylinder. The
ability to predictably vary the size of the gap between the piston and the cylinder can be useful in analyzing
piston-cylinder behavior.
The controlled clearance pressure is introduced through the CCP port on the back of the PG7607 platform. The
pressure is applied through the mounting post to the inside of the piston (see Figure 1, Ref. 8). The pressure is
contained by the two piston sealing O-rings (see Figure 1, Refs. 10a, 10b).
The piston sealing O-rings are positioned on the ends of the piston so that the deformation due to pressure
along the active zone of the piston is constant and parallel.
The expansion of the piston with pressure can be predicted using thick walled cylinder stress/strain relations and
the mechanical properties of the piston material (tungsten carbide). The result is 0.16 micron on the
diameter/MPa.
A typical 50 mm piston-cylinder assembly has a radial gap of 0.9 micron so a CCP of 3 MPa will reduce the gap
by about 50%. Around 5 MPa, the CCP may close the gap completely causing mechanical contact between the
piston-cylinder and damage to the parts.
Caution
A controlled clearance pressure (CCP) of about 5 MPa may close the gap between
the piston and cylinder completely causing metal to metal contact between the two
parts and possible damage.
3.2 [HEAD]
The natural reference level for the PG7607 piston-cylinder assembly is near the top of the cylinder cap. So that,
in practice, the actual reference level is at a conveniently identified location, a reference level offset is applied.
The reference level offset places the reference level at the bottom of the piston. This point is defined by the
horizontal line where the bottom of the piston meets the mounting post when the piston is mounted.
The reference level offset is included in the piston-cylinder file (see PG7000 Operation and Maintenance
Manual).
Note
When using a AMH-38 with the PG7607, the PG7607 reference level is 3 mm below
the reference level marked on the AMH vacuum chamber. This is because the
AMH-38 is marked for the PG7601.

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 10
Notes

Page 11 © 2010 Fluke Calibration
4. Maintenance, Adjustments and
Calibration
4.1 Piston-Cylinder Assembly and Disassembly
See the piston-cylinder installation and removal description in Section 2.2.2. The only possible further
disassembly of the piston cylinder is the removal of the cylinder retaining screw and adjustment mass
from the cylinder.
Caution
•Given the large diameter and small annular gap of the PG7607 piston-
cylinders, it is very difficult to insert the piston into the cylinder without the
aid of the alignment mechanism provided by the PG7607 platform mounting
post. There is a risk of cocking the piston in the cylinder. It is not
recommended that the piston ever be put into the cylinder when the piston
is not installed on the PG7607 mounting post.
•Disassembly of the piston-cylinder assembly exposes the piston-cylinder to
possible damage. The main risk is damage to the exposed critical working
surfaces. Only qualified personnel should undertake piston-cylinder
disassembly and reassembly and the instructions and recommendations
contained in this manual should be followed carefully throughout the
operation.
•NEVER touch the lapped surfaces (polished appearance) of the piston or
cylinder with your bare hands. Body oils and acids can permanently etch
the surfaces.
•The cylinder assembly (cylinder + cylinder cap + adjusting mass + cap
retaining screw + cylinder retainer) is part of the PG7607 mass load. Its
mass has been measured and is reported in the calibration report. When
handling these parts, take care not to change their mass by swapping
parts, contaminating them or leaving parts out in reassembly.

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 12
4.2 Cleaning Piston-Cylinders
The piston-cylinder cleaning methods described in the PG7000 Operation and Maintenance Manual
should be used with the following exceptions/comments:
•Water/detergent method: Due to the piston-cylinder’s large diameter and very small annular gap, it
is very difficult to insert the piston into the cylinder when the piston is not installed on the PG7607
mounting post. Without the alignment mechanism provided by the mounting post arrangement (see
Figure 1) there is a substantial risk of cocking the cylinder on the piston. When using the
water/detergent method to clean a PG7607 piston-cylinder, wash the cylinder and the piston
separately and do not attempt to put the piston into the cylinder until the piston is installed on the
PG7607 platform mounting post.
•Quick method: As it is difficult to hold the piston without making contact with its critical working
surface, install the piston onto the PG7607 platform mounting post to clean it (see Section 2.2.2).
4.3 Piston-Cylinder Recalibration
4.3.1 Mass of the Cylinder
The floating assembly of the PG7607 cylinder includes (see Figure 1):
•The cylinder and cap (4, 1).
•The cylinder cap screw (2).
•The adjustment mass (17).
•The cylinder cap O-ring (3).
•The cylinder stroke limiter (16).
To determine the mass of the floating cylinder assembly, the mass of all these parts must
be determined. The cylinder stroke limiter (16) is captivated in the piston retaining assembly
(5) and the retaining assembly must be disassembled to remove it. See Section 4.4 for
disassembly instructions for the piston retaining assembly.
4.4 Disassembly of Piston Retaining Assembly
The piston retaining assembly (see Figure 2) does not need to be disassembled as part of
routine maintenance. However, the piston retaining assembly captivates the cylinder stroke limiter that is
part of the of cylinder assembly whose mass must be determined when recalibrating the cylinder.

4. MAINTENANCE, ADJUSTMENTS AND CALIBRATION
Page 13 © 2010 Fluke Calibration
4.4.1 Disassembly Procedure
To remove the cylinder stroke limiter from the piston retaining assembly follow the
procedure below. To reassemble, follow the reassembly procedure in Section 4.4.2.
Numerical references in this procedure refer to Figure 2.
(See Section 4.1, Figure 1 for this step.) With the piston NOT installed, install the piston retaining
assembly (5) onto the mounting post (7).
Using circlip pliers, remove the spring retaining circlip (1) from the top of the assembly.
As the circlip is removed, the spring washer (2) will lift slightly as the springs
(3, 5) decompress.
Lift off spring washer (2).
Gently lift out the spring carrier (4) along with the four high stop springs (3) it carries.
This leaves behind, in the piston retaining nut (7), the cylinder stroke limiter (6) and the
four low stop springs (5). Take care that the springs do not drop down into the measured
pressure opening in the center of the mounting post.
Using tweezers, carefully remove the four low stop springs (5). Then lift out the cylinder
stroke limiter (6).
Caution
The cylinder stroke limiter (6) floats with the cylinder and is thus part of the
cylinder assembly mass. Take care not to contaminate this part when
handling it. It is preferable to avoid contacting this part with bare hands.
Figure 2. Piston Retainer Assembly
 Spring Retaining Circlip
Spring Washer
(4) HighStop Springs
Spring Carrier
(4) LowStop Springs
Cylinder Stroke Limiter
Piston Retaining Nut
Upper Piston Sealing O-ring (Brown, Viton, 2-029)
Mounting Post O-ring (Brown, Viton, 2-019)

PG7607™ OPERATION AND MAINTENANCE MANUAL
© 2010 Fluke Calibration Page 14
4.4.2 Reassembly Procedure
To reassemble the cylinder stroke limiter into the piston retaining assembly, follow the
procedure below. Numerical references in this procedure refer to Figure 2.
Remove the piston retaining nut (7) from the mounting post and set aside.
Flip over the spring carrier (4) and place the four low stop springs (5) into the four holes
on the bottom of the spring carrier (4) (the bottom of the spring carrier is the side
WITHOUT the white plastic ring).
Place the cylinder stroke limiter (6) into the center section of the spring carrier (4).
Be sure to orient the cylinder stroke limiter correctly: pointed end facing out in the
direction of the springs.
Caution
The cylinder stroke limiter floats with the cylinder and is thus part of the
cylinder assembly mass. Take care not to contaminate this part when
handling it. It is preferable to avoid contacting this part with bare hands.
Carefully slip the piston retaining nut (7) over the spring carrier (4), low stop springs (5)
and piston stroke limiter (6). Take care so that the springs do not come out of the holes
and so the piston retaining nut (7) does not cock on the spring carrier (4).
Verify that no springs have fallen out of place by pressing the spring carrier (4) into the
piston retaining nut (7) and compressing the springs. There should be about 3 to 4 mm of
movement. If there is less, one or several of the springs is probably sideways in the
space and the process should be repeated from Step ⊄above.
Place the four high stop springs (3) into the holes on the spring carrier (4).
Place the spring washer (2) on top of the high stop springs (3).
Install the spring retaining circlip (1). The spring washer (2) needs to be pressed down
compressing the springs slightly to allow the circlip (1) to engage in its seat in the
retaining nut (7).