Graphite Packing

[ozzie46]

How do you install graphite packing on steam engine pistons? My Simplex Loco pistons have 2 grooves, 1/8th wide by 3/16 in deep for packing to get the pistons steam tight but I know nothing about how to go about it.


For instance, how much friction should the piston have on initial insatllation? I assume they would free up some as you work the piston in the cyl.

Can you use a hose clamp (aka jubilee clip?) to squeeze the graphite rope tight enough to get the piston in the bore?

Will the graphite expand some once its in the bore?

I Keep reading about installing packing in steam engine articles but can find nothing on how to do it

Any help will be greatly appreciated.

Ron

[jma1009]

hi ron,
you need proper square graphite packing, not rope or string. the usual ME suppliers can provide. i make the grooves to fit the packing. cut the ends at an angle, soak in steam oil, and compress in tight. yes the piston will be (should be) tight to start with, but not too tight that you cant move it without considerable effort. it will bed down quite quickly especially if soaked in cylinder oil first. my guess is that you will find a 1/8" width slot not tight enough for 1/8" packing and you may need to go up to 4mm square stuff which is now a standard size. you may need to make up some strips of coiled shim as your grooves are a bit deep for 4mm packing, and even if you squash 3/16" square stuff in the vice to reduce its width your grooves may still be too deep. probably best to buy a selection of different sizes of square packing just in case.
cheers,
julian

[ozzie46]

Thanks Julian much apprecitaed. Now to find a supplier in the U.S.

Ron

[doubletop]

Jun 12, 2012 13:26:03 GMT ozzie46 said:

.............. Now to find a supplier in the U.S.

Ron

Just go to Polly Model Eng or Reeves in the UK and they'll ship to the US. I have stuff coming to NZ from both. The no VAT (sales tax) just about covers the shipping

shop.ajreeves.com/

www.pollymodelengineering.co.uk/


Pete

[ozzie46]

Thanks for looking in Pete and thanks for the info.

I found some packing at a local Hydraulic cyl repair place.

Ron