Anderson Greenwood Pilot Operated Safety Relief Valves (POSRV) Winterization Guidelines IOM, Anderson Greenwood-EN Manuals & Guides

ANDERSON GREENWOOD PILOT OPERATED SAFETY RELIEF VALVES (POSRV)

WINTERIZATIONGUIDELINES

The intent of these instructions is to acquaint the user with the heat tracing and insulating of theseproducts.

Pleaseread these instructions carefully.

AndersonGreenwood Pilot Operated Safety
Relief Valves (POSRV) are designed for use
in a wide variety of environments, including
locations where they may be exposed to low
ambient temperatures. In order to ensure
optimal performance, freeze protection
systems are commonly used on pilot operated
safety relief valves (POSRV) in cold climates to
keep them warm, and in particular, to prevent
freezing of liquids in the valve and tubing.
A typical freeze protection system consists of
two primary components: insulation and a heat
source, often an electric heating cable. These
components must be selected to work together
providing the freeze protection required in the
most efficient manner. It is recommended that
an organization with freeze protection expertise
be consulted to ensure the most appropriate
system is designed for your conditions.

Inaddition to electric heat cable,
in some cases steam tracing or
steam jacketing systems are chosen.
Either steam or electric freeze protection
systems are acceptable methods for use with
Anderson Greenwood Pilot Operated Pressure
Relief Valve as long as the following guidelines
are used.

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© 2017 Emerson. All Rights Reserved.

Engineering Doc. #05.9040.372 Rev. BA

VCIOM-03099-EN 19/07

ANDERSON GREENWOOD PILOT OPERATED SAFETY RELIEF VALVES (POSRV)

WINTERIZATION GUIDELINES

SERIES 200, 400, 500, 800 (FIGURES 1 AND 2)

• Main valve, pilot valve, tubing and accessories
can all be heat traced and/or insulated.

• Do not insulate over pilot exhaust vents or
bonnet vents since they must communicate
directly to atmosphere.

• Assure heat trace temperature does not
rise above 140°F (60°C) on surface of valve
to prevent damaging O-rings, diaphragms
and seals. Heat trace temperature should
be sensed and controlled at or near the pilot
valve. Consultthe factory if higher heat trace
temperatures are required for a particular
application. ThePOSRV serial number is
required for a factory response.

FIGURE 1

MODULATING POSRV

DO NOT insulate
overbonnet vent

DO NOT insulate

overpilot exhaust vent

Pilot valve

It is not necessary to
insulate pilot bonnet

Main valve

FIGURE 2

SERIES 200 SNAP ACTING POSRV

DO NOT
insulate
overpilot
exhaust vent

Pilot valve

Main valve

2

ANDERSON GREENWOOD PILOT OPERATED SAFETY RELIEF VALVES (POSRV)

WINTERIZATION GUIDELINES

SERIES 700 (FIGURE 3)

• Main valve, pilot valve, tubing and accessories
can all be heat traced and/or insulated.

• Do not insulate over pilot exhaust vent since it
must communicate directly to atmosphere.

FIGURE 3

SERIES 700 SNAP ACTING POSRV

DO NOT insulate

overpilot exhaust vent

Pilot valve

Main valve

SERIES 5200 (FIGURE 4)

• Do not insulate the main valve cap. Thiswill
hamper the convection cooling needed
to keep the main valve piston seals cool
and main valve dome filled with water.
Themain valve (except cap), pilot, tubing and
accessories can all be heat traced
and/orinsulated.

• Assure heat trace temperature does not rise
above 200°F(93°C) to prevent overheating
O-rings and seals. Also, a 200°F(93°C)
maximum heat trace temperature assures
that condensate will be maintained in the
main valve dome and condensate trap. Heat
trace temperature should be sensed and
controlled at or near the pilot valve.

FIGURE 4

SERIES 5200 MODULATING POSRV

It is not

necessary

to insulate

pilot bonnet

Pilot valve

DO NOT insulate
this region of cap

Main valve

3

ANDERSON GREENWOOD PILOT OPERATED SAFETY RELIEF VALVES (POSRV)

WINTERIZATION GUIDELINES

SERIES 90, 9000 (FIGURE 5)

• Main valve, pilot valve, tubing and accessories
can all be heat traced and/orinsulated.

• Do not insulate over pilot exhaust vents or
bonnet vents since they must communicate
directly toatmosphere.

• Assure heat trace temperature does not
rise above 140°F (60°C) on surface of valve
to prevent damaging O-rings, diaphragms
and seals. Heat trace temperature should
be sensed and controlled at or near the pilot
valve. Consult the factory if higher heat trace
temperatures are required for a particular
application. The POSRV serial number is
required for a factoryresponse.

FIGURE 5

MODULATING OR SNAP ACTING POSRV

DO NOT insulateover
bonnet vent

DO NOT
insulateover pilot
exhaust vent

Main valve

Pilot valve

It is not necessary to
insulate pilot bonnet

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Responsibility for proper selection, use, and maintenance of any product remains solely with the purchaser and end user.

Anderson Greenwood is a mark owned by one of the companies in the Emerson Automation Solutions business unit of Emerson Electric Co. Emerson Automation
Solutions, Emerson andthe Emerson logo are trademarks and service marks of Emerson Electric Co. All other marks are the property of their respective owners.

The contents of this publication are presented for informational purposes only, and while every effort has been made to ensure their accuracy, they are not to be
construed as warranties or guarantees, express or implied, regarding the products or services described herein or their use or applicability. All sales are governed
by our terms and conditions, which are available upon request. We reserve the right to modify or improve the designs or specifications of such products at any time
withoutnotice.

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