Bray Triple Offset - Manual (Page 5)

3 O & M
A D i v i s i o n o f B r a y I n t e r n a t i o n a l , I n c .
The Ultimate Critical Service Triple Offset Valve
O p e r a t i o n a n d M a i n t e n a n c e M a n u a l
2.2.2 Special Conditions for Safe Use
The following factors must be carefully considered in order
to ensure the valve is compatible with the atmosphere
in which it is applied. The system designer and/or end
user should formally address each item and carefully
to ensure continued compliance throughout the life of
the Tri Lok valve.
Titanium is not to be used in Group I, mining applications
due to the potential of ignition due to mechanical sparks
from impacts such as a spanner being dropped on the
valve. Please consult factory for details regarding
material limitations.
Temperature Considerations
The surface temperature of the Tri Lok valve is wholly
dependent on the ambient temperature in combination
with the temperature of the process medium. The
maximum surface temperature of the Tri Lok valve may
be calculated from the maximum ambient temperature
plus the maximum process medium temperature as
shown below:
Equation 1 - Surface Temperature Calculation
T
s(max)
= T
a(max)
+ T
p(max)
The system designer is responsible for ensuring the
maximum temperature, either inside the valve body or on
the external surface, will remain well below the ignition
temperature of the atmosphere. Additional protective
safety margin, including but not limited to: thermal
shut-off devices, and cooling devices.
Where the process medium is a liquid or semi-
solid material with a surface resistance in excess of
1 G-ohms, special precautions should be taken to ensure
the process does not generate electro-static discharge.
the process media remains below 1 m/s or provid-
to eliminate electrostatic build-up. Consultation to
EN 50404 is recommended.
Appropriate grounding may be necessary through the
use of grounding straps or other means.
When the Tri Lok valve is used near sources of high
current or magnetic radiation, a secure bonding to earth
ground should be made so as to prevent ignition due
to inductive currents or a rise in temperature due to
these currents.
Special consideration should be made regarding the
for the process medium to contain solid particulates. The
particles no greater than 1.0 mm in diameter through the
valve assembly where there is a high probability of solid
particulates. Larger particulate sizes may be deemed
appropriate based on the possibility of particulates
be well-documented by the system designer and/or end
user to ensure continued compliance through the life
of the valve.