Page 529 - Subyek Teknik Mesin - Forsthoffers Best Practice Handbook for Rotating Machinery by William E Forsthoffer

Be st Practice 8 .13 Pump Mechanical Seal Flush Best Practices
- Improper installation of mating ring into the gland resulting in flush/quench after isolation of piping/tubing up to the point
excessive leakage due to improper face contact. Note that if of the piping/tubing reinstallation.
backofmating ringisvisibly‘not flat’,thesameresultcan apply. - Assure that the proper durometer, material and size ‘O’ ring
- Stuffing box face TIR should be checked with dial indicator is supplied and lubricate seal sleeve ‘O’ ring with ‘Krytox’ or
on shaft. Seal chamber face flatness should be no more than equivalent lubricant.
0.005’ TIR. - Slide sleeve over shaft carefully.
- Installation of gland to stuffing box not using equal and - Install gland to seal chamber using equal and opposite
opposite tightening technique. Failure to tighten the nuts/ tightening technique. Prior to doing so, a sweep of the seal
capscrews properly can cock the mating ring, which will not chamber face is required to ensure proper sealing between
allow for proper contact between the faces and result in gasket/‘O’ ring on seal gland and seal chamber. A dial
excessive leakage between the seal faces. indicator should be attached to the shaft and the shaft will be
- Sleeve ‘O’ ring cut during installation, resulting in excessive rotated to cover a complete sweep of the seal chamber face.
leakage between shaft and sleeve. TIR should be no more than 0.005’.
- Tighten set screws to engage shaft/sleeve by equal and
opposite technique. Assure that a clean shaft surface is
Cartridge mechanical seal installation
available for all set screw locations. If not, use a file and
- Refer to pump vendor manual and maintenance records to emery cloth to remove any damaged spots. Be sure to
ensure proper cartridge seal will be used. completely clean shaft to remove all debris.
- Assure the seal chamber is cleaned and shaft is de-burred to - Completely remove setting clips. If setting clips are slid up
remove any sharp material that could damage seal sleeve ‘O’ on the gland, they can potentially fall back down to the
ring. sleeve or drive collar resulting in an ignition source (the
- Assure seal chamber is isolated from all flush and quench writer has experienced fires that have started due to this
connections systems. Plastic plugs need to be installed in all issue).

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