Emerson KEYSTONE GULF Installation Manual

KEYSTONE GULF VALVES CHECK VALVES MODEL MB

INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS

Before installation these instructions must be read fully and understood

INTRODUCTION

The instructions included within this installation
and operations manual are intended as a
guideline only. As they do not cover every
situation, this manual does not replace
common sense and expertise of the person
installing the valve and pipeline engineer(s).
Proper valve selection is the foundation for
successful installation and the End User is
responsible for ordering the correct valves.
Should you require assistance, please contact
Emerson.

While every effort has been made to ensure the
accuracy of the contents of this IOM, it is not
to be interpreted as warranties or guarantees,
expressed or implied, regarding the products
and services described herein or their use or
applicability. Emerson reserves the right to
modify or improve the designs or specifications
of such products at any time.

The use of the term “PED” throughout this
manual refer to the European Pressure
Equipment Directive 97/23/EC. Please note that
not all Emerson valve configurations comply
with CE/PED/ASME standards.

SPARE PARTS

WARNING

Do not attempt to work on any valve under
pressure, and depending on the service, valve
surface temperature may be hot. Use proper
protective equipment to protect against burns.
Also, provide safe means in case of uncontrolled
release of fluids.

Any misuse, unauthorized modification,
refurbishment by unqualified staff or use of
non-Emerson parts invalidates the Warranty
provided in the Terms and Conditions of Sale
and invalidate the CE Mark if applicable..

The Keystone Model MB wafer check valve
is a self-operating check valve designed to
prevent the backflow of gas or liquid media.
Initial opening of the discs begins when the
upstream pressure exceeds the downstream
pressure and the effective torque of the spring.
This pressure is called the “cracking” pressure.
Once the discs open, flow velocity determines
the position and stability of the discs. If the flow
velocity upstream of the check valve decreases
and/or stops, the springs force the discs to a
closed position.

If valve is resold or transferred, it is your
responsibility to forward this instruction
manual along with the product to the new
owner or transferee.

Emerson.com/FinalControl

© 2017 Emerson. All rights reserved.

VCIOM-04509-EN 17/10

KEYSTONE GULF VALVES CHECK VALVES MODEL MB

INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS

INSTALLATION

The following precautions should be taken to

1. Remove the valve from carton or packing
skid. Prior to installation, inspect valve(s)
for any damage and check valve(s) and
nameplate(s) for proper identification and
to be sure the valve is suitable for use in the
application.

2. The protective rust proof coating on the
internal parts of steel or cast iron valves
should be removed by brushing out with any
standard petroleum solvent (e.g. Varsol™,
Kerosene), and air dry. Ensure internal parts
operate freely.

3. Stainless Steel or Bronze valves need only
to be wiped clean and installed.

4. In horizontal flow installation, the hinge pin
must be vertical.

5. Ensure the sealing surfaces are free of dirt
and insert the valve between two companion
flanges of the same series as the valve and
place gaskets on flange faces. The arrow on
the valve or nameplate indicating direction
of flow should coincide with line flow. Install
studs through companion flanges and
tighten, using standard industry practice.

6. In liquid service we recommend valve be
installed at least five (5) pipe diameters
downstream from a pump discharge and/or
other pipefittings for maximum service life.

insure long service life of wafer check valves:

• Accurate sizing of wafer checks is crucial to
ensure an acceptable pressure drop and a long
service life.

• Flow velocities should be in the following
ranges:

Flow rate

Feet per second (ft/s) Meters per second (m/s)

Media

Liquid 3 to 11 0.91 to 3.35
Gas 20 to 250 6.1 to 76.2

• A minimum of 5 (five) pipe diameters should
be maintained between the wafer check and
likely causes of turbulence (i.e. pump discharge,
reducers, elbows, and tees, etc.).

• Maximum operating pressure reduces as
service temperature increases.

• It is the responsibility of the customer to ensure
valve is suitable for all service conditions of
the line, including but not limited to pressure,
temperature, and media. The application is
not to allow corrosion greater than 0.05 mm
/ year (0.002” / year). DO NOT use any valve
in applications where either the pressure
or temperature is higher than the allowable
working values or service media is incompatible
with materials of construction, which may cause
chemical attacks.

LIMITATIONS AND PRECAUTIONS

WARNING

Any misuse, unauthorized modification,
refurbishment by unqualified staff or use of non­Emerson parts invalidates the Warranty provided
in the Terms and Conditions of Sale and invalidate
the CE Mark if applicable.

Model MB dual disc wafer check valves are
not recommended for the following service
conditions:

• Pulsating flows.

•

Service condition requiring a “Full Port” opening.

• Installation directly to a butterfly valve or other
piping accessory that may interfere with the
opening or closing of valve discs.

• Vertical flow DOWN without prior factory
approval.

•

The design of the Model MB dual disc wafer check
valves has taken into account loadings appropriate
to its intended use and other reasonably
foreseeable operating conditions. Loadings
caused by traffic, wind and earthquake have not
been taken into account.

• Model MB dual disc wafer check valves are not
to be installed in service conditions greater

than Category III (Reference the PED).

2