VFlo Control Valves
2
GENERAL INFORMATION
The instructions presented below are for helping in un-packing,
installing and performing maintenance as and when needed on
Mascot VFlo ball valves. The manual should be thoroughly
reviewed by Product users and maintenance personnel before
performing any operation on the valve. Separate maintenance
instructions cover additional features (such as actuators, special
accessories, fail-safe systems, etc.).
For information on Mascot positioners, refer to the appropriate
Mascot Installation, Operation and Maintenance instructions.
Please follow the procedures laid down to avoid possible injury
to personnel or damage to valve parts. Any modification in this
product, or using non-factory or inferior parts, employing
maintenance procedures other than prescribed can affect
performance adversely; moreover, it can be dangerous to
personnel and equipment, and also void existing warranties.
WARNING :
It is mandatory to follow standard industry safety
practices. Personal protective and lifting devices must be used
as specified.
Note :
The onus of choosing the proper fastener material lies on
the customer. The supplier cannot know what the valve service
conditions or environment might exist. The standard body bolting
material for Mascot's is B7/2H. For applications above 800° F
and with stainless steel or alloy body valves B8 (stainless steel) is
optional. It is up to the customer therefore to consider the
material's resistance to general corrosion and stress corrosion
cracking. Every mechanical equipment needs periodic inspection
and maintenance. The details on fastener materials can be
obtained from your local Mascot representative or factory.
Unpacking
First step is to check packing list against the materials
received during the unpacking of the valve. Each shipping
container has lists describing the valve and accessories.
For lifting the valve from the shipping container, lifting straps
need to be positioned to avoid damage to tubing and
mounted accessories. Where valves are provided with a lifting
ring, please use the same for lifting. Valves up through 8-inch
may be lifted by the actuator lifting ring. Larger valves can be
lifted using lifting straps or hook through the yoke legs and
outer end of the body.
WARNING :
During lifting of a valve with lifting straps
through the yoke legs, one must have in mind that the
center of gravity may be above the lifting point and
support must be given to prevent the valve from rotating.
Serious injury to personnel or damage to nearby
equipment can take place if proper attention is not paid to
this factor.
On observation of damage in transit, shipper should be
contacted immediately.
The Mascot representative is always at your service whenever
needed.
Quick-Check
Before beginning, check the control valve as per the steps
mentioned below:
By making the appropriate instrument signal change, verify
for full stroke. The position indicator plate is mounted on the
actuator transfer case for observation. Position of the
indicator plate should change in a smooth, rotary fashion.
CAUTION :
The full torque load of the actuator cannot be
taken by the VFlo valve shaft. The shaft could twist and/or
shear if the ball were to seize and full torque continued.
There should be no leaks in the air connections. Any leaky
lines should be repaired by tightening or replacement.
Tighten of the packing nuts is to be done to slightly over
finger-tight and evenly.
CAUTION : Over tightening of packing nuts can cause
excessive packing wear and high shaft friction and shaft
rotation will be adversely affacted. Every short time valve
has been in operation, check the packing nuts to ensure
they are torqued properly. Do correction if necessary. Any
leaking in the packing box should be corrected by
tightening the packing nuts. The tightening should be only
enough to stop leakage.
In case of air failure, for observing the valve failure mode,
position the valve to mid-stroke and shut off the air supply to
the actuator or disconnect the instrument signal to the
positioner. The actuator indicator plate should move to either
fail/open or closed position. If not, the "Reversing the
Actuator Action" section in the actuator maintenance
instructions needs to be referred.
*Torque values are recommended for low and intermediate
strength bolting per ANSI B16.5 5.3.2. Higher torques may be
used with high strength bolting (ANSI B16.5 5.3.1). For all
cases the user must verify the selected bolting's ability to seat
the joint under expected operating condition. Higher strength
bolting and torque values are needed for long thrubolted
joints than shorter flanged bolting - depending on operating
conditions. **Lengths are based on ANSI B16.5 stud bolts and
raised face ends.
2.
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4.
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2.
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1.
Table 1 : Flange Bolting Specificatiions
Valve
ANSI
Bolt**
Torque* (ft. Lbs.)
Size
Class
Length
Low
Intermediate
(Inches)
Rating
(Inches) Strength Strength
150
2.5
23
61
1
300
3.0
46
122
600
3.5
46
122
150
2.75
23
61
11/2
300
3.5
82
218
600
4.25
82
218
150
3.25
46
122
2
300
3.5
46
122
600
4.25
46
122
150
3.5
46
122
3
300
4.25
82
218
600
5.0
82
218
150
3.5
46
122
4
300
4.5
82
218
600
5.75
132
353
150
4.0
82
218
6
300
5.5
132
353
600
6.75
199
531
150
4.25
82
218
8
300
6.25
199
531
600
7.5
296
789
150
4.5
132
353
10
300
6.25
199
531
600
8.5
420
1119
150
4.75
132
353
12
300
6.75
296
789
600
8.75
420
1119
