Flowserve Circpac HP - Manual (Page 5)

4.10 Disengage setting plates and store separately.
4.11 Inspect equipment and driver alignment in accordance with coupling
and/or equipment manufacturer’s instructions.
5 Piping and Control System
5.1 Proper piping and control system installation are imperative to correct
seal operation. Piping ports are detailed on the mechanical seal
assembly drawing and clearly marked on the mechanical seal
housing. Installation and operating instructions specific to Flowserve
control panels are available separately and must be carefully
followed.
5.2 Piping connections may include combinations of the following
examples where multiple descriptions may apply to each port
connection.
• Double barrier – inject clean external gas between a pair of rings
at a pressure typically 0.3 – 0.7 bar (5-10 psi) above upstream ring
pressure for zero emissions.
• Tandem purge – inject clean external gas between a pair of rings
at a pressure lower than upstream ring pressure and vent from the
same pair to a low pressure flare.
• Inboard gas purge – inject clean external gas or filtered product
gas between the first pair of rings at slightly higher pressure than
product (typically 0.2 - 0.3 bar [3-5 psi] differential) to maintain
clean inboard rings.
• Bearing purge – inject clean external gas before bearing ring at
higher pressure than bearing cavity (typically 0.2 – 0.3 bar
[3-5 psi] differential) for the purpose of restricting oil ingression,
typically vented through a dedicated port.
• Sensing/reference – connection to the reference port of a
differential pressure regulator to maintain constant purge or barrier
pressure differential across the downstream ring.
• Vent – connection to low pressure flare system or other approved
destination where vent pressure is the lowest pressure piping
connection.
• Drain – disposal of liquids including condensate or bearing oil
and for maintenance procedures such as in-place cleaning.
• Tandem sensing – connection to a pressure gage or transducer
to monitor the pressure between ring stages as a measure of seal
performance.
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