Spirax Sarco SGC40 User manual

IM-P130-29 CMGT Issue 7 1
1. Safety information
2. General product
information
3. Installation
4. Commissioning
5. Operation
6. Maintenance and
Spare parts
© Copyright 2017
Printed in France
IM-P130-29
CMGT Issue 7
1306050/7
SGC40 and SGS40
Sight Glasses
Installation and Maintenance Instructions

IM-P130-29 CMGT Issue 72

IM-P130-29 CMGT Issue 7 3
1. Safety information
Safe operation of these products can only be guaranteed if they are properly installed,
commissioned, used and maintained by qualified personnel (see Section 1.11) in
compliance with the operating instructions. General installation and safety
instructions for pipeline and plant construction, as well as the proper use of tools
and safety equipment must also be complied with.
Warning
The gaskets used in these units contain thin stainless steel support rings which may
cause physical injury if not handled and disposed of carefully.
Under certain conditions corrosive elements in the flow media can affect the inside
face of the window, particularly where caustic alkali and hydrofluoric acid are
present. Mica glass protectors must be used to protect the glass when the unit is
used on steam applications or when the ph is higher than ph9 or when the temperature
is above 150 °C with a ph greater than ph7 (see Section 2.1).
Regular inspection of the glass to check for thinning of the window must be
undertaken based on an assessment of your system. If there is evidence of thinning
or erosion damage, then the window should be replaced immediately. Always wear
eye protection when viewing the contents of the sight glass.
Reasonable steps should be taken to protect personnel from injury in the unlikely
event that the window breaks.

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1.1 Intended use
Referring to the Installation and Maintenance Instructions, name-plate and Technical
Information Sheet, check that the product is suitable for the intended use / application.
The products listed below comply with the requirements of the European Pressure
Equipment Directive 97 / 23 / EC and carry the mark when so required.
It should be noted that products rated as 'SEP' are required by the Directive not to
carry the mark.
The products fall within the following Pressure Equipment Directive categories:
Product Group 1
Gases
Group 2
Gases
Group 1
Liquids
Group 2
Liquids
SGC40 and
SGS40
DN15 ½"SEP SEP SEP SEP
DN20 ¾"SEP SEP SEP SEP
DN25 1" SEP SEP SEP SEP
DN32 1¼"2 1 SEP SEP
DN40 1½" 2 1 SEP SEP
DN50 2" 212SEP
DN65 2½"212SEP
DN80 3" 212SEP
DN100 4" 322SEP
i) These products have been specifically designed for use on steam, air or water /
condensate as stated in Groups 1 and 2 of the above mentioned Pressure Equipment
Directive. The products’ use on other fluids may be possible but, if this is
contemplated, Spirax Sarco should be contacted to confirm the suitability of the
product for the application being considered.
ii) Check material suitability, pressure and temperature and their maximum and
minimum values. If the maximum operating limits of the product are lower than
those of the system in which it is being fitted, or if malfunction of the product
could result in a dangerous overpressure or overtemperature occurrence, ensure
a safety device is included in the system to prevent such over-limit situations.
iii) Determine the correct installation situation and direction of fluid flow.
iv) Spirax Sarco products are not intended to withstand external stresses that may
be induced by any system to which they are fitted. It is the responsibility of the
installer to consider these stresses and take adequate precautions to minimise
them.
v) Remove protection covers from all connections and protective film from all name-
plates, where appropriate, before installation on steam or other high temperature
applications.

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1.2 Access
Ensure safe access and if necessary a safe working platform (suitably guarded)
before attempting to work on the product. Arrange suitable lifting gear if required.
1.3 Lighting
Ensure adequate lighting, particularly where detailed or intricate work is required.
1.4 Hazardous liquids or gases in the pipeline
Consider what is in the pipeline or what may have been in the pipeline at some
previous time. Consider: flammable materials, substances hazardous to health,
extremes of temperature.
1.5 Hazardous environment around the product
Consider: explosion risk areas, lack of oxygen (e.g. tanks, pits), dangerous gases,
extremes of temperature, hot surfaces, fire hazard (e.g. during welding), excessive
noise, moving machinery.
1.6 Isolation
Consider the effect on the complete system of the work proposed. Will any proposed
action (e.g. closing isolation valves, electrical isolation) put any other part of the
system or any personnel at risk?
Dangers might include isolation of vents or protective devices or the rendering
ineffective of controls or alarms. Ensure isolation valves are turned on and off in a
gradual way to avoid system shocks.
1.7 Pressure
Before attempting any maintenance consider what is or may have been in the
pipeline. Ensure that any pressure is isolated and safely vented to atmospheric
pressure before attempting to maintain the product, this is easily achieved by
fitting Spirax Sarco depressurisation valves type DV (see separate literature for
details) and consider double isolation (double block and bleed) and the locking or
labelling of closed valves. Do not assume that the system is depressurised even
when a pressure gauge indicates zero.
1.8 Temperature
Allow time for temperature to normalise after isolation to avoid the danger of burns
and consider whether protective clothing (including safety glasses) is required.
1.9 Tools and consumables
Before starting work ensure that you have suitable tools and/or consumables available.
Use only genuine Spirax Sarco replacement parts.
1.10 Protective clothing
Consider whether you and/or others in the vicinity require any protective clothing
to protect against the hazards of, for example, chemicals, high / low temperature,
radiation, noise, falling objects, and dangers to eyes and face.

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1.11 Permits to work
All work must be carried out or be supervised by a suitably competent person.
Installation and operating personnel should be trained in the correct use of the
product according to the Installation and Maintenance Instructions.
Where a formal 'permit to work' system is in force it must be complied with. Where
there is no such system, it is recommended that a responsible person should know
what work is going on and, where necessary, arrange to have an assistant whose
primary responsibility is safety.
Post 'warning notices' if necessary.
1.12 Handling
Manual handling of large and/or heavy products may present a risk of injury. Lifting,
pushing, pulling, carrying or supporting a load by bodily force can cause injury
particularly to the back. You are advised to assess the risks taking into account the
task, the individual, the load and the working environment and use the appropriate
handling method depending on the circumstances of the work being done.
1.13 Residual hazards
In normal use the external surface of the product may be very hot. If used at the
maximum permitted operating conditions the surface temperature of some products
may reach temperatures of 280 °C (536 °F).
Many products are not self-draining. Take due care when dismantling or removing
the product from an installation (refer to 'Maintenance instructions').
1.14 Freezing
Provision must be made to protect products which are not self-draining against frost
damage in environments where they may be exposed to temperatures below freezing
point.
1.15 Disposal
Unless otherwise stated in the Installation and Maintenance Instructions, these
products are recyclable and no ecological hazard is anticipated with their disposal
providing due care is taken.
1.16 Returning products
Customers and stockists are reminded that under EC Health, Safety and Environment
Law, when returning products to Spirax Sarco they must provide information on any
hazards and the precautions to be taken due to contamination residues or mechanical
damage which may present a health, safety or environmental risk. This information
must be provided in writing including Health and Safety data sheets relating to any
substances identified as hazardous or potentially hazardous.

IM-P130-29 CMGT Issue 7 7
2. General product information
2.1 General description
The SGC40 cast carbon steel and SGS40 stainless steel are double window sight glasses
having screwed, sanitary clamp, socket weld and flanged connections.
Standards
These products fully comply with the requirements of the European Pressure Equipment
Directive 97 / 23 / EC and carry the mark when so required.
Certification
These products are available with a manufacturer’s Typical Test Report and if specified
certification to EN 10204 3.1.
Note: All certification / inspection requirements must be stated at the time of order
placement.
Optional extras:
- Visual flow indicator flap to check the flow of the liquid in the pipeline.
- Spring: The visual flow indicator flap can be spring loaded for applications on vertical
lines or where there is high flowrates.
- Mica glass protectors for severe applications - When these have been specified the
nomenclature becomes SGC40M and SGS40M.
Please see table below to identify when Mica glass protectors are to be used.
Application Glass choice to be used
Steam or > pH9 Mica glass protectors and Borosilicate glass windows
>150 °C and > pH7 Mica glass protectors and Borosilicate glass windows
<150 °C and < pH7 Borosilicate glass windows only
Note: For further information see the following Technical Information Sheet TI-P130-28.
2.2 Sizes and pipe connections
½", ¾", 1", 1¼", 1½" and 2" Screwed BSP, NPT and Socket weld.
DN15, DN20, DN25, DN40 and DN50 Sanitary clamp connections to ASME BPE.
DN15, DN20, DN25, DN32, DN40, DN50, DN65, DN80 and DN100
Flanged EN 1092 PN40, ASME Class 150 and Class 300, JIS/KS 10 and JIS/KS 20.
Flanged versions have face-to-face dimensions in accordance with EN 558 Series 1.
Fig. 1

IM-P130-29 CMGT Issue 78
2.3 Pressure / temperature limits
SGC40 Carbon steel
 
 
Pressure bar g
Temperature °C
Steam
saturation
curve
Pressure psi g
Temperature °F
Pressure bar g
Temperature °C
Pressure psi g
Temperature °F
SGS40 Stainless steel
A
ED F
BCD
C
B
E
F
A D
C
B
B
C
D
E
E
F
F
Steam
saturation
curve

IM-P130-29 CMGT Issue 7 9
The product must not be used in this region.
A-B-B Flanged JIS 10 and KS 10.
A-C-C Flanged ASME 150.
A-D-D Flanged EN 1092 PN40.
A-E-E Flanged JIS 20 and KS 20.
A-F-F Screwed BSP, NPT, Sanitary clamp, Socket weld and Flanged ASME 300.
Body design conditions PN40
PMA Maximum allowable
pressure
SGC40 40 bar g @ 280 °C (580 psi g @ 536 °F)
SGS40 40 bar g @ 178 °C (580 psi g @ 352 °F)
TMA Maximum allowable
temperature
SGC40 280 °C @ 40 bar g (536 °F @ 580 psi g)
SGS40 280 °C @ 32.5 bar g (536 °F @ 472 psi g)
Minimum allowable temperature -10 °C (14 °F)
PMO
Maximum
operating
pressure for
saturated
steam service
PN40
SGC40 31.3 bar g @ 238 °C (454 psi g @ 460 °F)
SGS40 28 bar g @ 230 °C (406 psi g @ 446 °F)
ASME 150
SGC40 14 bar g @ 198 °C (203 psi g @ 388 °F)
SGS40 22.5 bar g @ 220 °C (326 psi g @ 428 °F)
ASME 300
SGC40 40 bar g @ 250 °C (580 psi g @ 482 °F)
SGS40 33 bar g @ 240 °C (478 psi g @ 464 °F)
JIS 10 and KS 10 14 bar g @ 120 °C (203 psi g @ 248 °F)
JIS 20 and KS 20 34 bar g @ 120 °C (493 psi g @ 248 °F)
TMO Maximum operating
temperature
SGC40 280 °C @ 40 bar g (536 °F @ 580 psi g)
SGS40 280 °C @ 32.5 bar g (536 °F @ 472 psi g)
Minimum operating temperature -10 °C (14 °F)
Note: For lower operating temperatures consult Spirax Sarco
Designed for a maximum cold hydraulic test pressure of: 60 bar g (870 psi g)

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A Flanged
B
D (window)
C
B
A1
Screwed and
Socket weld
A2
Sanitary clamp
2.4 Dimensions / weights (approximate) in mm and kg
Dimensions (mm) Weight (kg)
Size AA1 A2 B C D Flanged Screwed
Socket
weld
Sanitary
clamp
DN15 130 95 120 48.5 46.7 10 3.5 2 2
DN20 150 95 140 51 46.7 10 4.3 22.2
DN25 160 95 155 68.5 60.8 15 6.4 3.5 4
DN32 -150 -91.5 71.4 15 - 7 -
DN32 flanged 180 - - 72 60.8 15 7.8 - -
DN40 -150 202 91.5 71.4 20 -6.75 7.4
DN40 flanged 200 - - 86.5 71.4 20 10.5 - -
DN50 230 150 232 91.5 71.4 20 12.5 67.6
DN65 290 - - 126.5 113.2 30 27.7 - -
DN80 310 - - 134 113.2 30 31 - -
DN100 350 - - 143 113. 2 30 37 - -

IM-P130-29 CMGT Issue 7 11
2.5 Product name-plates
As standard the name-plates are stamped SGC40 and SGS40.
When the unit has been supplied or modified with Mica glass protectors its nomenclature
becomes SGC40M and SGS40M - Consequently the name-plate will be stamped
accordingly.
Standard name-plates

IM-P130-29 CMGT Issue 712
Fig. 2
Notes:
1. Before actioning any installation observe the 'Safety information' in Section 1.
2. Apply the appropriate grease to SGS40 stainless steel screwed units to avoid
cold welding.
Warning
The gaskets used in these units contain thin stainless steel support rings which may
cause physical injury if not handled and disposed of carefully.
Under certain conditions corrosive elements in the flow media can affect the inside
face of the window, particularly where caustic alkali and hydrofluoric acid are
present. Mica glass protectors must be used to protect the glass when the unit is
used on steam applications or when the ph is higher than ph9 or when the temperature
is above 150 °C with a ph greater than ph7 (see section 2.1).
Regular inspection of the glass to check for thinning of the window must be
undertaken based on an assessment of your system. If there is evidence of thinning
or erosion damage, then the window should be replaced immediately. Always wear
eye protection when viewing the contents of the sight glass.
Reasonable steps should be taken to protect personnel from injury in the unlikely
event that the window breaks.
Applications that incorporate sight glasses should have stop valves fitted on both the inlet
and outlet. It is imperative that the upstream stop valve is closed first in order to prevent
over pressurisation.
Sight glasses must be fitted on the outlet side of a steam trap in either a horizontal or
vertical pipeline in accordance with the flow arrow on the body. Warning: when the optional
visual flow indicator flap is requested for horizontal flow applications the hinge must be
placed uppermost otherwise it will not work for the purpose intended - See Figure 2. Where
the trap is a blast discharge type e.g. thermodynamic, the sight glass must be fitted at least
1 m (3 ft) from the trap. This is to ensure that the glass is not subjected to thermal shock
or pressure.
Ensure access is available for maintenance purposes.
3. Installation
Hinged at the top

IM-P130-29 CMGT Issue 7 13
The sight glass promotes turbulence in the sight glass when the fluid is passing through it.
The turbulent flow inside the sight glass permits any fluid to be detected.
Sight glasses can be used to detect blocked valves, strainers, steam traps and other pipeline
equipment. Sight glasses can also be used for inspection purposes, i.e. to compare the
colour of the fluid at different stages of the process, enabling adjustments to be made quickly
and effectively.
5. Operation
After installation or maintenance ensure that the system is fully functional. Carry out tests on
any alarms or protective devices.
4. Commissioning

IM-P130-29 CMGT Issue 714
6. Maintenance and Spare parts
Table 1 Recommended tightening torques
Item Size Quantity or
mm N m (lbf ft)
5
DN15 - DN20 817 A /F M10 x 35 12 (8.6)
DN25 - DN32 819 A /F M12 x 50 28 (20.7)
DN40 - DN50 819 A /F M12 x 60 38 (28.1)
DN65 - DN100 823 A /F M16 x 85 132 (97.4)
6.1 Maintenance
Note:
Before actioning any maintenance programme observe the 'Safety information' in
Section 1.
How to renew the windows and gaskets:
-Isolate the sight glass and allow the pressure and temperature to reduce to ambient
conditions.
-After isolation unscrew the cover bolts (5) and remove the old gaskets (4) and windows (3).
-Carefully clean the recess.
-Refit new gaskets and windows, ensuring that a gasket (4) is fitted to either side of each
window (3).
-Replace the covers (2) and cover bolts (5 - Apply the appropriate grease to SGS40
stainless steel bolting to avoid cold welding) and tighten to the recommended torque
(see Table 1).
-After maintenance has been completed, isolation valves should opened slowly to allow
pressure and temperature to build up in a controlled manner.
-Check for leaks.

IM-P130-29 CMGT Issue 7 15
5*
3
8
4
4
3
8
4
4
5*
Fig. 3
6.2 Spare parts
The spare parts available are shown in
solid outline. Parts drawn in a grey line
are not supplied as spares.
Available spares
Set of windows and gaskets 3, 4
Set of gaskets 4
Visual flow indicator flap
(not shown) 6
Mica glass protectors
(not shown) 8
How to order spares
Always order spares by using the
description given in the column headed
'Available spares' and state the size and
type of the sight glass.
Example: 1 off Set of windows and
gaskets for a Spirax Sarco DN20 SGC40
sight glass.
* Item 5 is not
an available
spare.

IM-P130-29 CMGT Issue 716