Mechanical Seal - DECCAN DP 50/30A Installation, Operation And Maintenance Manual

I N S T A L L A T I O N , O P E R A T I O N A N D M A I N T E N A N C E M A N U A L
checked frequently and replaced as service indicates. Six months might be a reasonable
expected life, depending on operating conditions. It is impossible to give exact
predictions. A packing tool should be used to remove all old packing from stuffing box.
Never reuse old and lifeless packing or merely add some new rings. Make sure the stuffing
box is thoroughly cleaned before new packing installed. Also check the condition of the
shaft or sleeve for possible scoring or eccentricity, make replacements where necessary.
New packing (non-asbestos) should be placed carefully into the stuffing box. If molded
rings are used, the rings should be opened sideways and the joints pushed into the stuffing
box first. The rings are installed one at a time, each ring seated firmly and the joints
staggered at about a90 °C rotation from each preceding joint.
Champion Style-3116-Graphited cotton greasy packing is used in the standard supply.
However packing suitable for liquid handled is also supplied against specific requirement.
Size of gland packing and position of lantern ring
Gland packing of fitted with 2+L+2 arrangement, L-Lantern ring.
Group I - 8 mm²
Group II & III - 10 mm²
Group IV & V - 12 mm²

6.2.2 MECHANICAL SEAL

General instruction for operation of the various mechanical seal arrangements are included
below. It is not feasible to include detailed instructions for all mechanical seals in this
booklet because of the almost unlimited number of possible combinations and
arrangements. Instead, seal manufacturer's instructions will be included as a separate
supplement to this book, where required.
 Mechanical seals are precision products and should be treated with care. Use
special care when handling seals. Clean oil and clean parts are essential to prevent
scratching the finely lapped sealing faces. Even light scratches on these faces could
result in leaky seals.
 Normally, mechanical seals require no adjustment or maintenance except routine
replacement of worn or broken parts.
 A mechanical seal which has been used should not be put back into service until
the sealing faces have been replaced or relapped.(Relapping is generally
economical only in seals two inches in size and above)
Four important rules which should always be followed for optimum seal life are:
 Keep the seal faces as clean as possible.
 Keep the seal as cool as possible.
 Assure that the seal always has proper lubrication.
 If seal is lubricated with filtered fluid, clean filter frequently.
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