Nagano Keiki GS5 User manual

TY1－3A 1／18
Rev.
2
INSTRUCTION MANUAL
FOR
GENERAL PURPOSE PRESSURE GAUGE
Model No. GS5□
NAGANO KEIKI CO., LTD.

TY1－3A 2／18
Rev.
2
TABLE OF CONTENTS
1．INTRODUCTION ------------------------------------------------------------------------------------------------------- 3
2．SPECIFICATIONS ------------------------------------------------------------------------------------------------------ 4
3．PRECAUTIONS FOR TRANSPORTATION, STORAGE AND UNPACKING -------------------- 8
4．STRUCTURE ------------------------------------------------------------------------------------------------------------- 9
5．PRINCIPLE OF OPERATION -------------------------------------------------------------------------------------- 10
6．INSTALLATION --------------------------------------------------------------------------------------------------------- 11
7．USAGE ---------------------------------------------------------------------------------------------------------------------- 13
8．INSPECTION AND MAINTENANCE -------------------------------------------------------------------------- 15
9．INSTRUCTIONS ON INSPECTION AND MAINTENANCE ------------------------------------------ 16
10．TROUBLESHOOTING ------------------------------------------------------------------------------------------------ 16

TY1－3A 3／18
Rev.
2
1. INTRODUCTION
Besides the temperature, flow rate, etc., the pressures is also an important factor as a
process variable. Thus, pressure measurement is one of the important parts in
manufacturing. The advance of the equipment and plant engineering technology requires
higher performances and more versatile functions of measuring instruments, and
manufacturers provide various models to meet such requirements. However, instruments
are selected or used improperly, they will not demonstrate their full functions, resulting
in a failure in proper measurement or accidents in the worst cases. This manual describes
the basic operations of the pressure gauges. Read enough it carefully for trouble-free and
efficient operations.
In this manual, strictly note that "DANGER" "WARNING", etc. are indicated for the items
that may cause peril of life or serious injury.
[Before Using Pressure Gauge]
Read well this manual carefully to use the pressure gauge properly and efficiently. Note
that this manual describes the basic operations of our general-purpose pressure gauges
but does not cover all necessary matters.
As for the matters not described in this manual, inquire at our office.
[Warranty]
If the delivered products within the warranty period (within one year from the delivered
date) are determined to be non-conforming products according to "Defects due to the
design or manufacturing by NKS", they are repaired or replaced with conforming products
free of charge.
However, please note that the following cases are excluded.
①Where the delivered products are disassembled, altered or where their parts are
replaced or where any new function is added by the customer or any third party.
②Where directions described in the instruction manual or catalog are not observed.
③Where the non-conformance is caused by deterioration due to use, natural
disaster, fire or other force majeure events.
④The secondary damage caused by the non-conformance of the products including
the above.
Regardless of recognition of miss handling by the customer, where any apparent
evidence of deformation, abrasion, burnout, etc. are seen in parts, they shall be excluded
from the warranty scope and the cost shall be paid.

TY1－3A 4／18
Rev.
2
[Definition of Safety Terms]
Safety precaution in this manual are classified as follows:
Ignoring this warning can cause serious injury or even death.
Ignoring this warning can cause an injury or even death.
Ignoring this warning can cause the material damage and the defectiveness of instrument
performance.
2. SPECIFICATIONS
(1) Pressure Ranges
(2) Performances
(The table below shows the classification specified in JIS B 7505-1.)
Unit : %
Accuracy class
Tolerance
*2
Range of scale A
Range of scale B
Class 1.6
±1.6
±2.4
Notes (*2) The value of tolerance shall be expressed by percentage to the pressure span.
Size Shape of case *1 Connection Pressure ranges
60DIA. A,B,D G1/4B,R1/4 0～0.1MPa →0～25MPa
－0.1～0MPa →－0.1～2.5MPa
75DIA. A,B,D G1/4B, G3/8B
R3/8
0～0.1MPa →0～40MPa
－0.1～0MPa →－0.1～2.5MPa
100DIA. A,B,D G3/8B,G1/2B
R3/8,R1/2
0～0.1MPa →0～40MPa
－0.1～0MPa →－0.1～2.5MPa
WARNING
CAUTION
DANGER

TY1－3A 5／18
Rev.
2
Gauge Type Range of scale A Range of scale B
Pressure gauge and
vacuum gauge
・Pmin+Ps×0.1≦P≦Pmin+Ps×0.9 ・ Pmin≦P＜Pmin+Ps×0.1
・ Pmin+Ps×0.9＜P≦Pmax
Compound gauge
・ Pmin+Ps×0.1≦P≦－Ps×0.05
・ +Ps×0.05≦P≦Pmin+Ps×0.9
It is defined range of scale B where
range of scale A and range of scale B
overlap.
・ Pmin≦P＜Pmin+Ps×0.1
・ －Ps×0.05＜P＜Ps×0.05
・ Pmin+Ps×0.9＜P≦Pmax
Pmin ：The smallest pressure in case of a pressure gauge.
The biggest pressure of the vacuum part in case of a compound gauge.
The biggest pressure in case of a vacuum gauge.
Pmax ：The biggest pressure in case of a pressure gauge.
The biggest pressure of the pressure part in case of a compound gauge.
The smallest pressure in case of a vacuum gauge.
Ps ：The pressure span.
P：The pressure that a Bourdon tube pressure gauge indicates.
The scale range of tolerance is indicated in Ⅰ～Ⅲ.
The symbol in the figure is indicated in the next, but a definition of an inequality Pmin
and Pmax is different in a pressure gauge, a vacuum gauge and a compound gauge, so
attention is needed.
： The value is included. And ： The value isn't included.
・In the case of a pressure gauge
Ⅰ-Range of scale（In the case of a pressure gauge）
Pmin：The smallest pressure Pmax ：The biggest pressure Ps ：Pressure span.
The range of scale A is made by subtracting less than 10% of each end of pressure
span.
The range of scale B is made of less than 10% of each end of pressure span.
Ps
Pmin Pmax

TY1－3A 6／18
Rev.
2
・In the case of a vacuum gauge
Ⅱ-Range of scale（In the case of a vacuum gauge）
Pmin：The smallest pressure Pmax ：The biggest pressure Ps ：Pressure span.
The range of scale A is made by subtracting less than 10% of each end of pressure
span.
The range of scale B is made of less than 10% of each end of pressure span.
・In the case of a compound gauge
Ⅲ-Range of scale（In the case of a compound gauge）
Pmin：The biggest pressure of the vacuum department
Pmax：The biggest pressure of the pressure department Ps ：Pressure span.
The range of scale A is made by subtracting less than 10% of each end of pressure
span and less than 5% each of upper and lower parts of zero point of a compound
gauge.
The range of scale B is made of less than 10% of each end of pressure span and less
than 5% each of upper and lower parts of zero point of a compound gauge.
But the scale range where range of scale A and range of scale B overlap will be range
of scale B.
Because zero points range of scale A and range of scale B overlap and dance on the
near pressure side when the biggest pressure of the vacuum department will be 5% of
the pressure span.
Ps
Ps
Pmin
Pmin
Pmax
Pmax

TY1－3A 7／18
Rev.
2
Size Normal
Vibration
-
resistant
－
V
60DIA.
○ ○
75DIA.
○ ○
100DIA.
○ ○
Temp. *3 －
5
～
45
℃ －
5
～
45
℃
Notes (*3) Ambient temperature and/or measurement temperature.
The pressure gauge is affected by the temperature and changes when an accurate value is
necessary, please correct it by the next formula.
α=0.4×10－3×(t－23)×P1
P= P1－α
( α : offset , t : ambient temperature and/or measurement temperature ,
P1: indicated pressure , P : actual pressure )
(3) Materials of Liquid-Contacting Parts
Size Application
Liquid
-
contacting parts
Adhesion
Socket
Bourdon tube
60DIA.
75DIA.
100DIA.
General use
BRASS
or
BRASS
CASTING
BRASS
or
ST.ST.
Soldering or
silver soldering
(4) Case Structure
Normal type : Not water-proof or dust-proof
Seal type : Sealed construction which is equivalent to JIS C 0920, IP32 but not sealed
completely

TY1－3A 8／18
Rev.
2
3. INSTRUCTION FOR TRANSPORTATION, STORAGE AND UNPACKING
(1) Transportation
Like other electric and electronic measuring instruments, be very careful not to apply
vibrations to the pressure gauge as far as possible when transporting it.
Never hit or drop the pressure gauge.
If the pressure gauge is dropped or applied impacts, it may be broken.
(2) Storage
Store the pressure gauge in a dry and free from vibrations and dust place. Use care not
to deform or drop the packages if it is necessary to pile up the packages of the products.
Store the product in a place with as less temperature variance as possible because
places subject to remarkable temperature variances may cause dew condensation in
the product.
(3) Unpacking
Handle the product with great care when unpacking it.
Unpack the product in a wide place in order not to drop it when taking it out of the
package.
After unpacking, check if the supplied product fills the specifications required by the
customer. Also check if the product is not damaged in transportation.
If the customer finds some problems, please contact the dealer that you purchased the
product or our office.
CAUTION

TY1－3A 9／18
Rev.
2
4. STRUCTURE
No. Name
1 Socket
2 Bourdon tube
3 Movement
4 Retaining tube
5 Window
6 Dial
7 Pointer
8 Bezel ring
9 Case
10 Blow-out disk
The basic structure is shown above.

TY1－3A 10／18
Rev.
2
5. PRINCIPLE OF OPERATION
The Bourdon tube is displaced of "A" due to the pressure introduced through the
Socket.
This displacement is transmitted to the Movement (scaling mechanism) via the rod, and
is scaled to turn the pointer to indicate pressure.
Figure.6-1 Principle of operation

TY1－3A 11／18
Rev.
2
6. INSTALLATION
(1) Install the pressure gauge so that the scale plate is vertical.
If it should be impossible to install the pressure gauge vertically, please inform us of
the installation angle when making an order.
(2) The blow-out disk on the back of the pressure gauge is so designed to pop out and relief
the pressure to backward in case that the Bourdon tube has burst.
Therefore, when installing the pressure gauge, leave a space which allows the blow-out
disk to pop out behind it. If the pressure gauge is installed before a panel, leave a 10 mm or
more space between it and the panel, or make a hole (of 25 mm or more in diameter) in the
panel so as to allow the blow-out disk to pop out.
Leave 10 mm or more spaces around the blow-out disk of the pressure gauge.
Unless the blow-out disk functions act properly, resulting in dangerous accidents such
as the window may be broken.
(3) Install the pressure gauge free from leakage.
If the mounting threads are parallel threads, use a suitable gasket. If they are tapered, wind
sealing tape, etc. around them.
If they are parallel threads, it is recommended to use union nuts since they allow the
installation direction to be freely changed.
A frame-B (surface mounting) pressure gauge is installed on a panel, and the customer
only has to tighten the union nuts. When tightening the union nuts, be careful not to
apply an excessive force to the pressure gauge. Otherwise, the pressure gauge case may
be distorted, resulting in errors. Be sure to apply a wrench to appropriate positions of
the pressure gauge.
CAUTION
WARNING
CAUTION

TY1－3A 12／18
Rev.
2
(4) Note that, in liquid measurement, head difference between the pressure outlet port and
pressure gauge has bad influences upon the accuracy.
If a 0 to 0. 1 MPa pressure gauge is installed one meter higher than the pressure outlet
port in order to measure the water pressure, the pressure gauge reads a value 0.01 MPa
lower than the actual pressure. This error corresponds to 10% F. S. On the contrary, if
a pressure gauge is one meter lower than the pressure outlet, it reads a value 10%
higher than the actual pressure.
It is also possible to set the pointer higher or lower by the estimated error in advance,
if the installation position is known. A pressure gauge with a zero point adjusting
pointer can be zero-adjusted after it is installed on the site.
(5) Use flexible pressure pipes in order not to distort the pressure gauge and transmit
vibrations of the equipment to it. Clamp the pipes to eliminate resonance.
(6) Avoid installing the pressure gauge near a boiler or in a place exposed to heat radiation
as far as possible. If it is necessary for the pressure gauge to be installed in such a place,
protect it with a shielding plate or the like to prevent it from being directly exposed to the
radiated heat.
(7) It is recommended that a cock or valve be installed in the inlet of the pressure gauge for
easy and efficient maintenance.
(8) If the temperature of fluid to be measured is over 80℃, do not lead such fluid into the
pressure gauge directly. Install a pipe siphon to lower the fluid temperature.
(9) Condensate is produced in steam measurement. Tilt the lead pipe to prevent condensate
from being collected. Connect a drain plug to the end of the lead pipe.
(10) If it is necessary to install the pressure gauge in a place with mechanical vibrations,
install a panel apart from the vibration source and mount the pressure gauge on it if
possible.
Connect flexible copper pipe, etc. between the outlet port and pressure gauge.
If the lead pipe is made of steel, stainless steel or other hard material, vibrations are
transmitted to the pressure gauge via the lead pipe and it is useless to separate the
pressure gauge from the vibration source.
CAUTION

TY1－3A 13／18
Rev.
2
(11) If the pressure gauge is directly installed on the pressure pipe and vibrations are
transmitted, minimize the riser length. A long riser may boost vibrations.
7. USAGE
(1) Use the pressure gauge to measure pressures less than 3/4～2/3 of the full scale.
Never apply any pressures over the maximum pressure (i.e., the full scale value). In
case that the pressure element (Bourdon tube) may be broken, resulting in injury or
damages to the peripheral device and equipment.
(2) When dismounting the pressure gauge, be sure to reduce the pressure to zero (i.e.,
atmospheric pressure), and then dismount the gauge with care.
When dismounting the pressure gauge, be sure to close the valve to prevent fluid from
spouting out. If the valve is not closed, fluid spouts out, resulting in a scald or injury.
(3) Do not remodel the pressure gauge.
Do not attempt to remodel the product itself or provide it with additional functions.
(4) Do not glue the blow-out disk or make any other alterations to it.
If the blow-out disk is glued or the like, it fails to function properly. If the Bourdon tube
should burst, the window breaks, resulting in quite dangerous accidents.
WARNING
WARNING
DANGER

TY1－3A 14／18
Rev.
2
(5) If fluid having pressure variance is led into the pressure gauge, the pressure gauge may
become defective earlier. Most troubles are caused by such pressure variance and
mechanical vibrations.
Pressure variances may be reduced by a restriction installed at the inlet of the pressure
gauge.
The other is a dampener, which is a variable restriction type and connected as a screw
coupling of the pressure gauge. It is adjusted while observing shaking of the pointer of
the pressure gauge. In adjustment, close the dampener fully, then open it gradually.
In adjustment, do not stop down the restriction to the extent that the pointer stops
shaking, because it is unknown in such a condition whether the accurate pressure is
indicated. Thus, adjust the restriction to the extent that the pointer slightly shakes.
(6) As shown in (3) Materials of Liquid-Contacting Parts on page 7/18, the liquid contacting
parts of this pressure gauge are mainly made of brass and stainless steel, which are not
suitable to some substances. For such substances, diaphragm type gauges or proper
gauges should be selected.
Do not use this pressure gauge for fluids which may corrode the liquid contacting
parts.
If corrosive fluid flows through this pressure gauge, the pressure element (Bourdon
tube) may be damaged or burst and it flows out, resulting in injury or damages to the
peripheral device and equipment.
(7) For measuring oxygen, use an oil-free pressure gauge.
A general-purpose gauge may sometimes have oil in it.
Such oil may react with oxygen, resulting in fire or explosion.
(8) For details, read through JIS B7505-1 and make every effort to use the gauge in safety.
CAUTION
WARNING
DANGER

TY1－3A 15／18
Rev.
2
8. INSPECTION AND MAINTENANCE
(1) Observe the legal regulations and carry out maintenance once or more a year periodically.
(2) If the customer should find cracks in the cover glass or deterioration of the blow-out disk,
be sure to replace the pressure gauge.
If the Bourdon tube should burst, the cover glass is damaged, and resulting in
dangerous accidents.
(3) Dismount the pressure gauge on the site, and check its indication (including hysteresis)
using a pressure standard gauge such as a weight type pressure gauge or liquid column
pressure gauge.
(4) A pressure gauge with a throttle may not read the zero point, and the pressure gauge
does not seem to be zero-adjusted properly. Be sure to dismount the throttle and check
the gauge.
(5) For pressure gauge control, be sure to prepare a ledger and manage the gauges
according to the tag numbers of the gauges, if the gauges are numbered, and the serial
numbers marked on the gauges. Periodical check records help the customer to be
informed of the accuracy tendency of the gauges.
If the zero point of the gauge was corrected by 0.5% in maintenance before last, corrected
by 1% in the last maintenance and correction by 3% is needed this time, for example the
accuracy of this pressure gauge has been deteriorated acceleratedly.
If it is left without adjustment, it may probably break out. (This also apply to hysteresis.)
Periodical check enables preliminary prediction. Thus, be sure to prepare a ledger and
make check records to use the pressure gauges in the optimum conditions at all times.
If the accuracy of the pressure gauge has been deteriorated at acceleratedly, ask the
nearest dealer or office for repair service.
WARNING

TY1－3A 16／18
Rev.
2
9. INSTRUCTIONS ON INSPECTION AND MAINTENANCE
The Metric Law specifies that certified instruments can not be repaired by any parties other
than the authorized manufacturers or repairers. Zero point adjustment falls under the
category of repair. Note that the pressure gauge can only be zero-adjusted by the
authorized manufacturer or repairer.
10. TROUBLESHOOTING
If some trouble occurs, see Table 10 Trouble shooting below and take the appropriate
countermeasures. If the trouble can not be eliminated by such countermeasures, contact
the dealer or our office.

TY1－3A 17／18
Rev.
2
Countermeasures
1. Provide the pipe with a filter. 2. Open the valve. 1. If the ambient temperature is too
high, re-install the pressure gauge in a different position. If process fluid is hot, use a pipe siphon, etc. to lower the.
2. Re-install the pressure gauge in a
different position.
3. When using a dampener.
1. Use a thicker pipe. 2. Adjust the restrictions properly.
Possible causes
1. Pressure is zeroed. (Pipe is clogged with
foreign matters contained in fluid.)
2. The valve is closed. 1. The operating temperature range is
exceeded.
2. Wear of the movement due to vibrations. 3. Wear of the movement due to fluctuating
pressure.
1. Process fluid is too viscose. Or the pipe is
too thin for the process fluid viscosity.
2. Dampener is stopped down excessively.
Check points
1. Check if pressure is applied to (fluid flows
through ) the pressure gauge.
2. Check if the valve of the pressure gauge is
open.
1. Check if the fluid and ambient temperatures
are within the operating temperature range of the pressure gauge.
2. Check if excessive vibrations are not applied
to the pressure gauge.
3.
Check if excessive fluctuating pressure is not
applied to the pressure gauge.
1. Viscosity of process fluid and pipe thickness. 2. Degree of stopping down the dampener.
Troubles
Pointer does
not move.
The pointer
does not indicate pressure.
Slow
response.
Table.10 (1/2) Trouble Shooting

TY1－3A 18／18
Rev.
2
Countermeasures
1. Use a pressure gauge of higher
range.
Take an overpressure prevention countermeasure.
2. Provide the pipe with a filter. 3. Re-install the pressure gauge in
a different position.
When using a dampener.
1. Use a pressure gauge of higher
range.
Take an overpressure prevention
countermeasure.
2. Be careful not to apply impacts
to the gauge.
Possible causes
1. Bourdon tube is deformed by an
excessive pressure.
2. Clogging with foreign matters
contained in fluid.
3. Wear of the movement due to
vibrations or fluctuating pressure.
1. Bourdon tube is deformed by an
excessive pressure.
2. Shift of the pointer or deformation of
the Bourdon tube due to impacts.
Check points
1. Check whether or not an excessive
pressure is applied.
2. Check whether or not the throttle is
clogged.
3. Check whether or not excessive
vibrations or fluctuating pressure are applied to the pressure gauge.
1. Check whether or not an excessive
pressure is not applied.
2. Check whether or not the pressure
gauge is dropped or impacts are applied to it.
Troubles
Pointer does not read zero
when pressure gauge is
dismounted from
piping.
Pointer indicate over
scale point.
Table.10 (2/2) Trouble Shooting