Dixon Bayco 2180 Operating and maintenance manual

Maintenance & Operating
Instructions
For
Dixon Bayco
2180 Air Relief Valve,
Authorized Repair Center
Repair Kit
Canada:
Dixon Group Canada Limited
Innisfil (Barrie), Ontario
Phone: [phone]
Fax: [phone]
Toll Free: 877-963-4966
E-mail: [e-mail]
USA:
Dixon Bayco USA
Chestertown, Maryland
Phone: [phone]
Fax: [phone]
Toll Free: 800-355-1991
E-mail: [e-mail]
Mexico:
Dixva, S. de R.L. de C.V.
Monterrey, N.L
Phone: [phone]-DIXON (34966)
Fax: [phone]
E-mail: [e-mail]
Europe:
Dixon Group Europe Ltd
Preston, England
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
Asia Pacific:
Dixon (Asia Pacific) Pty Ltd Wingfield,
South Australia
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]
dixonvalve.com
For Sales and Service Contact

2180 Air Relief Valve Repair Kits
2 877.582.3569 2180 AIR RELIEF VALVE RK
Repair Kit Part Number
Description
2180RK15
15 (+2/-0) PSI Repair Kit
2180RK18
18 (+2/-0) PSI Repair Kit
2180RK15A
15 (+2/-0) PSI Repair Kit
2180RK18A
18 (+2/-0) PSI Repair Kit
No.
Description
Included in Repair Kit
1
Vent Cowl
No
2
Top Cover
No
3
Spring Seat
Yes
4
Diaphragm
Yes
5
Spring
Yes
6
Washer
Yes (4)
7
Spacers
No, Do not use with this
kit
8
Bolt
Yes (4)
9
Cup Seal Upper Half
Yes
10
Cup Seal Lower Half
Yes
11
Valve Plate
Yes

2180 Air Relief Valve Repair Kits
2180 AIR RELIEF VALVE RK 877.582.3569 3
To properly operate and maintain your Dixon Bayco 2180 air relief
valve, the following instructions are provided. Please read with care
as improper handling or maintenance may cause a hazardous
condition. These instructions are intended for use with, and refer to,
the 2180 air relief valve with set pressures of 15 PSIG and 18 PSIG.
These instructions, and the contents of this kit should not be used
with any other valve. Please ensure that you have the correct kit for
your valve and note that the 15 PSIG spring and the 18 PSIG spring
are not interchangeable.
Do not modify your Dixon Bayco air relief valve in any
manner other than as described in these instructions. Failure to
comply with these instructions including disassembly,
tampering or modifications using processes and parts not
described in these instructions or supplied with this will void the
product warranty and could result in personal injury and
extensive property damage.
Replace and Report: Immediately remove from service any air relief
valve that is not performing satisfactorily. Return and report the
problem to your Dixon Bayco distributor for warranty consideration.
Air Relief Valve Repair Procedure
Disassembly
Refer to attached parts diagram throughout the following
procedure.
1. Remove the air relief valve to a clean environment taking care not
to damage the pipe thread during removal.
2. Remove any residual surface contamination, dirt, debris from the
external surfaces before proceeding with disassembly.
Dixon Bayco air relief valves are held together under
considerable spring load. Ensure that the vent cowl (1) and top
cover (2) are restrained, using a vice or similar clamping device,
before attempting to undo the four bolts (8) securing the top
cover (2) to the vent cowl (1). Ensure that appropriate personal
protective equipment, including eye protection, is worn
throughout. Failure to comply with these safety precautions
may result in personal injury.

2180 Air Relief Valve Repair Kits
4 877.582.3569 2180 AIR RELIEF VALVE RK
4. With the air relief vent valve clamped, as described above, break
the existing tamper proof seal.
• For leaded wire seals: cute the wire, remove wire from bolt
and discard.
• For cup seals (as shown in items 9 and 10): Carefully pry
the cup seal away from the bolt using a flat bladed screw
driver. Discard both cup seal halves.
5. With the air relief valve clamped, as described above, remove all
four bolts (8) and washers (6).
6. When all bolts have been removed, the clamping arrangement
holding the vent cowl to the top cover should be slowly and carefully
released.
7. Fully disassemble and lay out all of the components of the valve.
8. Carefully inspect all components for signs of damage or wear.
Items 3-6 and 8-11 are contained in this repair kit and must be
replaced during rebuild.
9. Clean the inside of the top cover (2) and vent Cowl (1) taking
particular care to ensure that the valve-seating surface on the vent
cowl is free of surface contamination. Vent cowl seating surface must
be clean and smooth to create proper sealing surface, sanding with
200-400 grit sandpaper is recommended. Ensure that all debris is
removed from the interior of the top cover (2). Blow out as required,
since, residual debris may prevent the valve from operating correctly.
10. Layout the contents of the valve and replace items 3-6 and 8-11
with the parts included in the kit.
11. Spacers may be found in your existing valve. These spacers are
to be discarded. This repair kit contains a spring, with either a +2–0
PSI, or +/-1 PSI tolerance (dependent on kit purchased), that should
provide the correct valve opening pressure without the use of
spacers. NO SPACERS ARE TO BE USED WITH THIS REPAIR
KIT. Please note that although the springs have been factory set to
provide the required opening pressure, individual variables related to
specific valves and their applications might result in a rebuilt valve
having an opening pressure that falls outside of the expected
tolerance band. . In the event that the required opening pressure
(either 15 PSIG or 18 PSIG as noted on the kit) cannot be obtained
through use of the spring alone, ensure that you have the correct
repair kit and contact your Dixon Bayco sales representative
immediately.

2180 Air Relief Valve Repair Kits
2180 AIR RELIEF VALVE RK 877.582.3569 5
Assembly
Assemble the valve using the following procedure, referring to the
diagram as needed.
1. Place vent cowl (1) on the table with threaded portion lowermost.
2. Place valve plate (11) onto the seating surface of the vent cowl (1)
ensuring that the flat sealing surface is facing down (as shown in the
diagram) and in contact with the vent cowl seating surface.
3. Next place the diaphragm (4) onto the valve plate (11) so that the
center hole of the diaphragm is aligned with the stem of the valve
plate and the four cutouts on the outer edge of the diaphragm are
aligned with the threaded holes in the vent cowl (1).
4. Place the spring seat (3) on to the diaphragm (4) and the stem of
the valve plate (11).
5. Place spring (5) onto the stem of the valve plate (11) and on top of
the spring seat (3).
6. Place top cover (2) onto the top of the spring and, using a suitable
clamping device, bring the top cover and vent cowl (1) together,
ensuring that the diaphragm (4) is still aligned with the threaded holes
on the vent cowl. Check to ensure that the through holes in the top
cover are also aligned with the threaded holes in the vent cowl.
7. When the valve assembly is satisfactorily clamped together, take
the bottom half of the tamper proof cup seal (10) and place it on the
top cover flange (2) so that the hole in the cup seal is aligned with
one of the holes in the top cover flange.
8. Place a washer (6) on each of the four bolts (8) and thread each
bolt in turn into the valve assembly, as shown. Ensure that one of the
bolts passes through the tamper proof cup seal lower half (10) as
described in the step above.
9. Place the upper half of the tamper proof cup seal (9) onto the
assembled lower half (10) and press firmly to snap the two halves
together.
10. When all four bolts have been securely fastened, the valve
assembly may be unclamped and is now ready for testing.

2180 Air Relief Valve Repair Kits
6 877.582.3569 2180 AIR RELIEF VALVE RK
Air Relief Valve –Theory of Operation
All Dixon Bayco air relief valves are spring-loaded system-pressure
actuated devices consisting of a valve disc held in a closed position
against a valve seat by means of spring pressure. The pressure in
the system to be protected always acts on the valve disc and would
tend to open the valve, however the spring load is set so as to ensure
that the pressure in the system, at normal operating pressures, is
insufficient to open the valve. However, when the system pressure
builds to a level when the pressure load on the valve disc is equal to
the load exerted by the spring, the valve will begin to open. If the
pressure in the system were to be held at this level, the load acting to
open the valve and the spring load acting to keep the valve closed
would remain in equilibrium and the valve would be neither open nor
closed. In such circumstances the valve will tend to flutter on the
valve seat and may release a small amount of air but will not be
relieving significant pressure from the system. This point is known as
the warning pressure or cracking pressure.
If the pressure in the system continues to rise, the load acting on the
face of the valve, and tending to open the valve will also continue to
rise and will begin to exceed the load exerted by the spring, which
tends to keep the valve closed. When the opening load, due to
system pressure, exceeds the closing load, due to spring force, the
valve will open, and, as long as the system pressure remains
sufficient, will stay open. This point is known as the opening pressure
or set pressure (also referred to as rated or popping pressure). The
difference between the crack pressure and opening pressure varies
between valves and is also related to the system flow rate. However
the two should not be confused, as there is a significant difference in
pressure between the two points.
If the system pressure continues to rise, the valve will continue to
open and will relieve more and more air until the valve is fully open.
At this point the valve will be relieving close to its maximum airflow
rate, further increase in system pressure will show only relatively
minor increases in flow rate. If the system pressure decreases the
relieving airflow rate will reduce and the valve will start to close but
will not fully reseat until some pressure below the opening pressure,
this pressure is known as the reseating pressure and the difference
between the two pressures is known as “blowdown”.

2180 Air Relief Valve Repair Kits
2180 AIR RELIEF VALVE RK 877.582.3569 7
In practice the valve should be matched to the system to be protected
such that the maximum airflow rate of the valve is never utilized, i.e.
the valve should be capable of relieving a sufficient volume flow rate
of air at the opening pressure to ensure that the system pressure
drops significantly. If the valve is open and the system pressure
continues to rise above the opening pressure then the valve is
relieving less air than is being put into the system. This is a potentially
dangerous situation that may lead to over pressurization. Air relief
valves should always be matched to the system to be protected such
that the relieving airflow rate of the valve at the maximum allowable
system pressure, and ideally at the opening pressure, is well in
excess of the system input flow rate at that same pressure.
Pressure and Vacuum Relief Valve Terminology

2180 Air Relief Valve Repair Kits
8 877.582.3569 2180 AIR RELIEF VALVE RK
Testing
The opening pressure of this valve may indicate differently depending
on the test equipment, instrumentation and air supply used. Where
possible the valve should be tested using identical conditions and the
same equipment as will be found on the system to be protected.
When this is not practical the test set-up should, as closely as
possible, approximate the conditions of the system to be protected.
Additionally the calibration of your test system should be checked
against your actual system by comparing the opening pressure of the
same relief valve on both systems.
1. Ensure that your air supply is rated to at least 100 PSI and that at
least 250 SCFM of air flow is available. If the air supply flow rate is
much less than the rated flow rate of the relief valve, the relief valve
will appear to relieve at a lower pressure than the rated value. This
discrepancy arises because the relief valve is a spring device that is
designed to lift slightly before the set relief (opening) pressure, but
will not flow a significant volume of air until the air reaches the
opening pressure. If the SCFM flow rate is low the air relief valve will
relieve a volume of air at lift pressure that cannot be made up by the
supply source, therefore the tester will not be able to reach the
opening pressure setting. In this situation the maximum pressure
read on the tester pressure gauge will be the initial lift pressure and
not the rated opening pressure.
All test equipment should be rated suitable for use with
high pressure.
2. Ensure that all supply lines and connections are at least ¾".
3. Ensure that all relevant instrumentation is correctly calibrated.
The most accurate results will be obtained when the relief valve to be
tested is connected to an accumulator or air receiver tank such that
the dynamic effect of the compressor system is reduced. Failure to do
so may result in an indicated opening pressure lower than the actual.
4. Screw the pressure relief valve to be tested into a 2" port on your
test system using pipe sealant on the air relief valve threads.
5. Open supply pressure isolation valve and allow air receiver tank
pressure to rise.

2180 Air Relief Valve Repair Kits
2180 AIR RELIEF VALVE RK 877.582.3569 9
6. Tank pressure should be allowed to rise at a rate of approximately
2 PSI / second. Flow rates greater than this will cause the relief valve
to flutter rapidly. In this condition the valve plate inertia may cause the
apparent opening pressure to be lower than the calibrated value and
will make accurate testing impossible.
7. The relief valve will start to discharge at a pressure slightly below
the rated value, at this pressure some hissing may be evident but the
pressure in the tank should continue to rise (assuming air source
provides a sufficient flow rate). The valve opening pressure (RATED
VALUE) can be read on the tester pressure gauge when the valve
plate (11) reaches an equilibrium (open) position.
8. If the air supply provides a flow rate in excess of the
maximum flow rate capacity of the relief valve at the relieving
pressure, the valve will not be able to relieve a sufficient volume
of air to prevent tank pressure from continuing to rise. In this
condition serious personal injury and extensive property
damage may occur due to over pressurization of test
components.
Valve Installation
1. Prior to installation, clean any dirt or foreign matter from threading
surfaces.
2. Install air relief valve in positions ranging from vertical (0°) to
horizontal (90°). Do not install valve in inverted position.
3. Install air relief valve with exhaust area positioned so exhaust
vents safely (preferably down as shown in attached diagram). In
horizontal applications, ensure that the small vent hole in the side of
the top cover is facing downward. Downward venting helps prevent
dirt or debris from entering the valve.
4. Apply pipe sealant to threading surfaces prior to installation.
5. Thread the valve into place by hand and tighten using a crescent
wrench (or equivalent) across the hex flats.

2180 Air Relief Valve Repair Kits
10 877.582.3569 2180 AIR RELIEF VALVE RK
Care and Handling
Brand new Dixon Bayco air relief valves are tested at the factory and
are in proper working condition when shipped. Air relief valves are
designed to be tough and to provide long service with reasonable
care and handling.
Operation and Maintenance Instructions
1. Weekly visual inspection of the valve is recommended.
2. Ensure that the valve body and exhaust vents are kept clear of
buildup.
3. Ensure that exhaust vents remain clear of all obstructions.
4. Inspect the valve regularly to ensure thread tightness. Excessive
vibration may cause valve to loosen over time.
The Factory produced Dixon Bayco air relief valve is assembled with
tamper resistant screws and is pre-set at the factory to customer
requirements. Any attempt to disassemble or adjust settings for any
reason will void the manufacturer’s warranty. See warranty section
below for warranty details related to the use of this.
Should any problems arise with the valve, remove from service
immediately and contact your Dixon Bayco distributor.
Dixon Bayco Warranty
For complete warranty information, please refer to the latest
Dixon catalog.