Flowserve X-200 - Manual (Page 8)

3.3 For pressurized dual seal mode of operation, supply a clean
compatible barrier fluid to the inlet port at a pressure at least 1.7
bar (25 psi) above the pressure of the product acting on the outside
of the inner seal. The barrier fluid should be piped from the outlet
port past a pressure gauge and through a flow control valve to
waste or recovery system. The valve in the outlet line should be
adjusted to a flow adequate to remove seal generated heat and to
maintain the pressure between the X-200 inner and outer seals at
least 1.7 bar (25 psi) above the product pressure acting on the
outside of the inner seal. Flowserve can supply information on
barrier fluid flow requirements based on seal size, product tem-
perature, barrier fluid characteristics, and shaft speed.
3.4 For unpressurized dual seal mode of operation, supply a clean
compatible buffer fluid to the inlet port at a pressure below that of
the product acting on the outside of the inner seal. The buffer fluid
should be piped from the outlet port past a pressure gauge and
through a flow control valve to waste or recovery system. The valve
in the outlet line should be adjusted to a flow adequate to remove
seal generated heat and to maintain the pressure between the
X-200 inner and outer seals below that of the product pressure
acting on the outside of the inner seal. Flowserve can supply
information on buffer fluid flow requirements based on seal size,
product temperature, barrier fluid characteristics, and shaft speed.
3.5 The Flowserve supply tank is designed to work with the X-200
seal to form a self-contained sealing system. The circulating
feature in the X-200 provides a positive buffer / barrier fluid flow
from the seal cavity to the Supply Tank and back to the seal. In
most cases the natural cooling of the piping and tank are adequate
to remove seal generated heat. Cooling coils are available with the
supply tank to extend operating limits. The supply tank can be used
with the X-200 seal in the dual pressurized, Figure 8, or dual
unpressurized, Figure 9, operating modes.
3.6 Good piping practices:
• minimize line losses
• use large diameter tubing
• only upward sloping lines
• use long radius bends
• minimize component losses
• optimize for thermosyphon
• check rotation direction
• test for leaks
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