KEYSTONE
Figure 990/991 ButterFly valves
InstallatIon, operatIon and maIntenance InstructIons
1 INTrOducTION
Keystone Figure 990/991 is a rubber lined
butterfly valve suitable for use on all fluids
except those designated as ‘unstable’
according to the Pressure equipment Directive,
97/27/eC.
Figure 990 is available in sizes 25 mm to
300 mm and has a maximum working pressure
of 10 barg over a temperature range of -10°C
to +150°C. Figure 990 has a cast iron body of
two piece design which enables the use of a
one piece disc stem.
Figure 991 is available in sizes 25 mm to
150 mm and has a maximum working pressure
of 10 barg over a temperature range of -10°C
to +150°C. Figure 991 has a cast stainless
steel body of two piece design complete with
an integral notch plate for handlever use, and
this body also enables the use of a one-piece
disc stem.
the one piece disc stem provides the minimum
possible flow restriction when the valve is
fully open.
Potentially dangerous practices:
• disregarding instructions
• improper use of product
• use of insufficiently qualified personnel
application pressure/temperature must not be
higher than the pressure/temperature limits
shown on the datasheet.
application medium must be in accordance
with the Keystone Chemical Compatibility list.
2 STOragE
When valves are to be stored for some time
(2 months or more) before being fitted, storage
should be in the original delivery crates or
cases.
Storage conditions
the valves should be stored off the ground in a
clean, dry indoor area.
Protect the valve from temperature and
humidity extremes, and exposure to excessive
dust, moisture, vibration, deformations,
sunlight and ozone.
recommendations
1. temperature: storage temperature below
25°C, above 0°C preferable below 15°C.
2. Humidity: storage conditions should be such
that condensation does not occur, store in
a dry environment. Maximal 50% relative
humidity.
3. light: valve rubbers should be protected
from light, in particular direct sunlight or
strong artificial light with high ultra violet.
4. Ozone: storage rooms should not
contain any equipment generating ozone.
e.g. lamps, electric motors.
ImpOrTaNT
Before valves are being installed or used the
following actions are recommended.
1. Valves/parts have to be inspected and
thoroughly cleaned if required.
2. Rubber parts need to be greased with silicone
grease if not present anymore.
3. All surfaces in contact with seats have to be
thoroughly cleaned and greased with silicone
grease if stored for more than 5 months.
© 2017 emerson. all rights reserved.
Emerson.com/Finalcontrol
VcIOm-00760-EN 17/12
Before installation these instructions must be fully read and understood
