Greasing and sizing the packing rings

[Frosty]

Originally Posted by jehardiman;

I take it you do not have a degree in Marine Engineering. This is one of those thing you should take to a professional as you can kill people real fast with a shaft that big.

Only if he dropped it on some ones head , this is baby stuff.

Packing a gland is greasy string, you stuff it in ,, hence it is also called a stuffing box.

You could use your underpants if you had to--

[jehardiman]

Originally Posted by Frosty

Only if he dropped it on some ones head , this is baby stuff.

Packing a gland is greasy string, you stuff it in ,, hence it is also called a stuffing box.

You could use your underpants if you had to--

He's talking about a 150mm (6") shaft. Those don't use an unformed packing anymore, because of the increase in shaft speed. Old shafts would have used a v formed flax seal ~ 5-10% of shaft diameter inboard the gland bearing and water lubricated...a constant freshwater flow comming through the lantern ring around the shaft and collected by the gland lip to prevent overheating. Modern high speed shafts use engineered dripless seals, generally custom sprung carbon-steel-carbon or HDPE-bronze.

[ldigas]

Originally Posted by jehardiman

He's talking about a 150mm (6") shaft. Those don't use an unformed packing anymore, because of the increase in shaft speed. Old shafts would have used a v formed flax seal ~ 5-10% of shaft diameter inboard the gland bearing and water lubricated...a constant freshwater flow comming through the lantern ring around the shaft and collected by the gland lip to prevent overheating. Modern high speed shafts use engineered dripless seals, generally custom sprung carbon-steel-carbon or HDPE-bronze.

The shaft I'm actually interested is 70mm in diameter, but that is the size large enough that they do not sell packaged sealing systems (which usually is sold for shafts up to 50 or 60mm).
Would 6mm or 9mm packing rings be an appropriate for that diameter?

[jehardiman]

You can get a 70mm flexible dripless seal. Just google it. I know PYI makes a carbon-steel packingless fitting that size. Is it that you need the packing to be the inboard stern tube bearing also? As for the packing, just measure the existing stuffing box, or are you designing a stuffing box?

[ldigas]

Originally Posted by jehardiman

You can get a 70mm flexible dripless seal. Just google it. I know PYI makes a carbon-steel packingless fitting that size. Is it that you need the packing to be the inboard stern tube bearing also? As for the packing, just measure the existing stuffing box, or are you designing a stuffing box?

I'm designing the stuffing box (along with everything else from the output flange of the engine to the propeller).

I will try to post what I've come up with tomorrow, in form of at least a picture if not a dwg file.