Dixon BAYCO 2180RK15, BAYCO 2180RK18A, BAYCO 2180RK18, BAYCO 2180RK15A, BAYCO 2182RK15 Maintenance & Operating Instructions

Maintenance & Operating Instructions

For Sales & Service Contact

For

BAYCO 2180 AIR RELIEF VALVE,

AUTHORIZED REPAIR CENTER REPAIR KIT

Part Numbers:

2180RK15…………15 (+2/-0) PSI Repair kit
2180RK18…………18 (+2/-0) PSI Repair kit
2180RK15A ………15 (+1/-1) PSI Repair kit
2180RK18A ………18 (+1/-1) PSI Repair kit

USA:

Dixon Bayco USA

Chestertown, Maryland
Phone: [phone]
Fax: [phone]
Toll Free: 800-355-1991
E-mail: [e-mail]

www.dixonbayco.com

Mexico:

Dixva, S. de R.L. de C.V.

Monterrey, N.L
Phone: [phone]-DIXON (34966)
Fax: [phone]
E-mail: [e-mail]

www.dixonvalve.com

Asia Pacific:

Dixon (Asia Pacific) Pty Ltd

Wingfield, South Australia
Phone: [phone]
Fax: [phone]

E-mail: [e-mail]

www.dixonvalve.com.au

Canada:

Dixon Group Canada Limited

Innisfil (Barrie), Ontario
Phone: [phone]
Fax: [phone]
Toll Free: 877-963-4966
E-mail: [e-mail]

www.dixongroupcanada.com

Europe:

Dixon Group Europe Ltd

Preston, England
Phone: [phone]
Fax: [phone]
E-mail: [e-mail]

www.dixoneurope.co.uk

- 1 - 090088 R8

No.

DESCRIPTION

INCLUDED IN REPAIR KIT

1 VENT COWL NO

11

VALVE PLATE

YES

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

- 2 - 090088 R8

IMPORTANT: To properly operate and maintain your 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 15psig and 18psig. 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 15psig spring and the 18psig spring are not interchangeable.

CAUTION: Do not modify your 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 & report the problem to your Dixon Bayco distributor for warranty
consideration.

Air Relief Valve Repair Procedure

DISASSEMBLY

IMPORTANT: Refer to the attached parts diagram throughout the following procedure.

Remove the air relief valve to a clean environment taking care not to damage the pipe thread during
removal.

Remove any residual surface contamination, dirt or debris from the external surfaces before proceeding
with disassembly.

WARNING: 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.

With the air relief valve clamped, as described above, break the existing tamper proof seal.

For leaded wire seals: Cut the wire, remove wire from bolt and discard.
For cup seals (as shown items 9 & 10): Carefully pry the cup seal away from the bolt using a flat
bladed screwdriver. Discard both cup seal halves.

With the air relief valve clamped, as described above, remove all four bolts (8) and washers (6).

When all bolts have been removed, the clamping arrangement holding the vent cowl to the top cover should
be slowly and carefully released.

Fully disassemble and lay out all of the components of the valve.

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.

- 3 - 090088 R8

Clean the inside of the top cover (2) and vent Cowl (1) taking particular care to ensure that the valve­seating 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.

Layout the contents of the valve and replace Items 3-6 and 8-11 with the parts included in the kit.

IMPORTANT: Spacers (7) may be found in your existing valve. THESE SPACERS ARE TO BE

DISCARDED. This repair kit contains a spring, with either a +2–0psi, or +/-1psi tolerance

(dependant 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 15psig or 18psig 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.

ASSEMBLY

Assemble the valve using the following procedure, referring to the diagram as needed.

Place vent cowl (1) on table with threaded portion lowermost.

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 diagram) and in contact with the vent cowl seating surface.

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).

Place the spring seat (3) on to the diaphragm (4) and the stem of the valve plate (11).

Place spring (5) onto the stem of the valve plate (11) and on top of the spring seat (3).

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.

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.

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.

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.

When all four bolts have been securely fastened, the valve assembly may be unclamped and is now ready
for testing.

- 4 - 090088 R8

AIR RELIEF VALVE – THEORY OF OPERATION

All 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”.

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.

- 5 - 090088 R8

- 6 - 090088 R8

Pressure and Vacuum Relief Valve Terminology

Pressure

Flow Rate

Opening

"Set"

"Rated"

"Popping"

Warning

"Hissing"

"Cracking"

Reseating Fully Open

Blowdown

Seating Pressure

Nominal System Pressure

Typical System
Pressure Range