Flowserve ST Series - Manual (Page 4)

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1.10 Pressure testing of the ST/QBM, ST/MRA, ST cartridge
canister dual seal prior to installation is possible but not
necessary. If pressure testing is desired then pressure test
at 1.7 bar (25 psig) but never more than 3.4 bar (50 psig) with
dry nitrogen or instrument air. Prior to testing Flowserve must be
consulted to determine acceptable gas leakage rates. If bench
testing is desired the tests may be conducted if and only if
Flowserve has been consulted regarding the safety of testing
the seal canister on the bench. Bench test safety issues may
exist and cause physical injury and damage.
Caution: Bench test pressure never to exceed 3.4 bar (50 psig)
2 ST/QBM, ST/MRA, ST Cartridge Seal Installation
Tools needed:
• Open end wrenches for nuts or bolts
• Allen wrenches for cap screws and set screws
• Lubricant for O-rings
2.1 Attach the seal housing to vessel flange and/or gear box.
Each bottom entry mixer may have a different procedure for
attaching the seal and mixer drive to the vessel. Follow the
assembly instructions and recommendations of the manufac-
turer of the equipment. Do NOT use the seal canister piping
to lift and handle the seal.
2.1.1 Lubricate the shaft and flange bores over which O-rings
will slide with an appropriate approved lubricant. The ST line
of seals is typically used in bioprocessing applications where
only deionized water is an acceptable lubricant. However,
because of the poor lubricating properties of deionized water
it is recommended that a better lubricant be used if possible.
2.1.2 Line up the shaft with the seal cartridge sleeve. The seal
canister will be attached to the bottom of the vessel flange OR to
the gear box and vessel flange. In either case the shaft must be
slid through the center of the seal cartridge from a position above
the seal. This position can contribute to binding and/or twisting of
the seal sleeve as the shaft moves through it. Note: If the seal
canister is attached to a 90° gear box, the weight of the motor
off-set to one side puts a large torque on the seal canister which
may distort the canister that is fit into the mixer flange.