Spirax Sarco AVS32 User manual

IM-P123-17 ST Issue 4 1
IM-P123-17
ST Issue 4
1234150/4
1. Safety information
2. General
product information
3. Installation
4. Commissioning
5. Operation
6. Maintenance
7. Spare parts
AVS32 Stainless Steel Air Vent
for Steam Systems
Installation and Maintenance Instructions
© Copyright 2015
Printed in GB

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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 on this
document) 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.
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. The products
fall within the following Pressure Equipment Directive categories:
Product Group 2
Gases
Group 2
Liquids
AVS32 SEP SEP
i) The products have been specifically designed for use on steam, air or water/
condensate which are in Group 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 before installation.
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. Safety information

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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 The system
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 systems
Ensure that any pressure is isolated and safely vented to atmospheric pressure.
Consider double isolation (double block and bleed) and the locking or labelling of
closed valves. Do not assume that the system has depressurised even when the
pressure gauge indicates zero.
1.8 Temperature
Allow time for temperature to normalise after isolation to avoid danger of burns.
If parts made from Viton have been subjected to a temperature approaching
315°C (599°F) or higher, it may have decomposed and formed hydroflouric acid. Avoid
skin contact and inhalation of any fumes as the acid will cause deep skin burns and
damage the respiratory system.
If parts made from PTFE have been subjected to a temperature approaching
260°C (500°F) or higher, they will give off toxic fumes, which if inhaled are likely to
cause temporary discomfort. It is essential for a no smoking rule to be enforced in
all areas where PTFE is stored, handled, or processed as persons inhaling the fumes
from burning tobacco contaminated with PTFE particles can develop 'polymer fume
fever'.
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.
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.

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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 in excess of 300°C (572°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 Safety information - Product specific
See the relevant Sections of the attached Installation and Maintenance Instructions
for specific details relating to these products.
1.16 Disposal
Unless otherwise stated in the Installation and Maintenance Instructions, this product
is recyclable and no ecological hazard is anticipated with its disposal providing due
care is taken, except:
Viton:
- Can be landfilled, when in compliance with National and Local regulations.
- Can be incinerated, but a scrubber must be used to remove Hydrogen Flouride,
which is evolved from the product and with compliance to National and Local
regulations.
- Is insoluble in aquatic media.
PTFE:
- Can only be disposed of by approved methods, not incineration.
- Keep PTFE waste in a separate container do not mix it with other rubbish, and
consign it to a landfill site.
1.17 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.

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2. General product information
2.1 Description
The AVS32 is a stainless steel maintainable balanced pressure thermostatic air vent for
use on steam systems. It has an integral flat strainer screen and straight connections.
All pressure bearing components are produced by TÜV approved suppliers in accordance
with AD-Merkblatt WO/TRD100.
Standards
This product fully complies with the requirements of the European Pressure Equipment
Directive 97/23/EC.
Certification
This product is available with certification to EN 10204 3.1.B.
Note: All certification/inspection requirements must be stated at the time of order placement.
Note: For additional information see Technical Information Sheet TI-P123-16.
2.2 Sizes and pipe connections
½", ¾" and 1" screwed BSP or NPT.
½", ¾" and 1" socket weld ends to BS 3799.
½", ¾" and 1" butt weld ends to EN 12627.
DN15, DN20 and DN25 standard flange to EN 1092 PN40,
ANSI B 16.5 Class 150 and 300, JIS/KS 10K and JIS/KS 20K.
Fig. 1 AVS32

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The product must not be used in this region.
The product should not be used in this region or beyond its operating range as
damage to the internals may occur.
A - B Screwed, socket weld, butt weld and flanged ANSI 300.
A - C Flanged EN 1092 PN40.
A - D Flanged JIS/KS 20K.
A - E Flanged ANSI 150.
F - G Flanged JIS/KS 10K.
Body design conditions PN40
PMA Maximum allowable pressure 50 bar g @ 50°C(725 psi g @ 122°F)
TMA Maximum allowable temperature 400°C @ 35 bar g (752°F @ 507 psi g)
Minimum allowable temperature -200°C(-328°F)
PMO Maximum operating pressure
for saturated steam service 32 bar g (464 psi g)
TMO Maximum operating temperature 287°C @ 32 bar g (549°F @ 464 psi g)
Minimum operating temperature 0°C(32°F)
Note: For lower operating temperatures consult Spirax Sarco.
Designed for a maximum cold hydraulic test pressure of: 75 bar g (1 088 psi g)
Pressure bar g
Temperature °C
Steam
saturation
curve
2.3 Pressure/temperature (ISO 6552)
Pressure psi g
Temperature °F

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Note: Before actioning any installation observe the 'Safety information' in Section 1.
Referring to the Installation and Maintenance Instructions, name-plate and Technical
Information Sheet, check that the product is suitable for the intended installation:
3.1 Check materials, pressure and temperature and their maximum values. If the maximum
operating limit of the product is lower than that of the system in which it is being fitted,
ensure that a safety device is included in the system to prevent overpressurisation.
3.2 Determine the correct installation situation and the direction of fluid flow.
3.3 Remove protective covers from all connections and the protective film from all name-plates,
where appropriate, before installation on steam or other high temperature applications.
3.4 The AVS32 should be installed with the capsule in a horizontal plane with the cap at the
top, and be positioned at the highest point of the main, or plant where the air collects.
For maximum removal of air the discharge should be as free as possible, piped to a
safe location (see Figure 2).
3.5 The air vent should not be insulated.
3.6 Welding into the pipeline -There is no need to remove the operating capsule from the
product providing the welding is performed using the electric arc method. For specific
weld procedures consult the relevant National and International welding standards.
3.7 Ensure adequate space is left to remove the cover from the body for maintenance.
Minimum withdrawal distance is 37 mm (1½").
3. Installation
AVS32
Drain to a safe place
Separator
Steam
FTS14
Condensate
Fig. 2 Fig16 DCV41

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6. Maintenance
Note: Before actioning any maintenance programme observe
the 'Safety information' in Section 1.
Warning
The body/cover gasket contains a thin stainless steel support ring which may
cause physical injury if it is not handled and disposed of carefully.
6.1 General information
Before undertaking any maintenance on the air vent it must be isolated from the supply line,
and any pressure allowed to safely normalise to atmosphere. The air vent should then be
allowed to cool. When reassembling, ensure that all joint faces are clean.
Maintenance can be completed with the air vent in the pipeline, once the safety procedures
have been observed. It is recommended that new gaskets and spares are used whenever
maintenance is undertaken. Ensure that the correct tools and necessary protective equipment
are used at all times. When maintenance is complete open the isolation valves slowly and
check for leaks.
6.2 How to fit a new capsule and seat:
-Remove the cover (1) and spring (17) from the body (8) by unscrewing the two cover bolts (9).
-Remove the capsule (2) and spacer plate (18).
-Unscrew the valve seat (3) from the body (8).
-Clean or replace the strainer screen (5).
-Replace the valve seat (3) and tighten to the recommended torque (see Table 1).
-It is recommended to fit a new cover gasket (7) reassemble the spacer plate (18) ensuring
that it is located centrally on the valve seat (3).
-Reassemble the capsule (2), spring (17) and cover (1).
Note: Care must be taken to ensure the cover bolts (9) are progressively tightened to the
recommended torque (see Table 1).
After installation or maintenance ensure that the system is fully functional. Carry out tests on
any alarms or protective devices.
4. Commissioning
The operating element is a capsule containing a small quantity of a special liquid with a boiling
point below that of water. In the cold conditions that exist at start-up, the capsule is relaxed.
The valve is off its seat and is wide open, allowing unrestricted removal of air. This is a feature
of all balanced pressure traps/air vents and explains why they are well suited to air venting.
5. Operation

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Fig. 3
6.3 How to clean or replace the strainer screen:
-Remove the cover (1) and spring (17) from the body (8) by unscrewing the two cover bolts (9).
-Remove the capsule (2) and spacer plate (18).
-Unscrew the valve seat (3) from the body (8).
-Clean or replace the screen (5) as required.
-Replace the valve seat (3) and tighten to the recommended torque (see Table 1).
-It is recommended to fit a new cover gasket (7), reassemble the spacer plate (18) ensuring
that it is located centrally on the valve seat (3).
-Reassemble the capsule (2), spring (17) and cover (1).
Note: Care must be taken to ensure the cover bolts (9) are progressively tightened to the
recommended torque (see Table 1).
5
17
2
18
3
7
9
Table 1 Recommended tightening torques
Item Part or
mm N m (lbf ft)
3Valve seat 24 A/F 115 - 125 (82 - 89)
9Cover bolts 16 A/F M10 x 30 23 - 27 (16 - 19)
1
8

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The spare parts available are shown in heavy outline. Parts drawn in a broken line are not
supplied as spares.
Available spares
Capsule and seat assembly set 2, 3, 17, 18
Strainer screen (packet of 3) 5
Set of cover gaskets (packet of 3) 7
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 air vent.
Example: 1 - Capsule and seat assembly set for a Spirax Sarco DN25 AVS32 air vent.
7. Spare parts
Fig. 4
5
17
2
18
3
7

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