Flowserve Dual Gas Barrier Seals - Manual (Page 12)

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8. Functional recommendations
To assure reliable, long-life operation of your Dual Gas Barrier Seal, the following
guidelines should be observed.
It must be ensured that the machine is protected against penetration by dust
and / or that dust deposits are removed at regular intervals so that they cannot
exceed a thickness of 5 mm on the surfaces of the faces.
8.1 Observe the start-up. The seal barrier cavity must be pressurized before pump
start-up and at all times during pump operation. For best performance, do not
cavitate or run the pump dry. Open valves to flood pump with product fluid
before start-up. Maintain the seal barrier gas pressure even when the pump is
not running.
8.2 Do not exceed corrosion limits. Your Flowserve seal is designed to resist
corrosion by most chemicals. However, do not expose the seal materials of
construction to products outside of their corrosion limits. The seal assembly
drawing lists the materials of construction. Consult Flowserve for chemical
resistance ratings.
8. Do not exceed the pressure limits of the seal design. Do not let the barrier
gas pressure fall below 25 psi (2 bar) above the seal chamber pressure.
8.4 Do not exceed the maximum temperature limits of the seal design.
8.5 Do not operate at speeds lower than the seal's minimum speed, if applicable.
8.6 For uni-directional designs, do not turn the shaft opposite to the direction
arrow indicated on the gland.
9. Reset pump impeller
To reset the pump impeller, follow plant safety procedures, etc., see 5.1.
9.1 Reinstall the setting devices.
9.2 Loosen the cartridge drive collar set screws.
9. Adjust the impeller clearance following pump manufacturer’s instructions.
9.4 Tighten the set screws on the cartridge drive collar using a cross-tightening method,
see Figure 6 .
! Inaccurate tightening of these screws can lead to unsafe situation as mechani-
cal seal may move out of the seal chamber when pressure is applied..