STeve,
Rubber insertion gaskets are limited to 700 kPa rating. I would use compressed mineral fibre (CMF) without a problem. (CAF not allowed because of the asbestos). You can download Klinger's software for calculating the pressure rating and bolt torques.
If you are feeling rich Spiral wound metallic fibre could be used but the application doesnt warrant it.
Geoff
--- Steve McKenzie <Mechproj@xtra.co.nz> wrote:
Have put in a 250NB (355 OD) PN20 PE slurry line; expected max pressure 16 bar. Flanged joints are stub flanges, gramophone finish, Table F steel backing rings. Gaskets are 3mm reinforced insertion rubber. Have had a few blowouts at 10 bar as we are not yet up to full output. Bolts were not being tightened properly but I think the problem is more than that.
Need a better gasket.
Have considered:
No gasket; just tighten her up; the slurry solids might blind off any minor
leaks.
CAF gasket. Not my favourite as the CAF is probably too hard for the PE
grooves to get a good bite on.
Spiral wound or corrugated metal.
Metal backing ring to rubber: my favourite but where do you buy them?
Metal ring which cuts into the plastic as the joint is tightened.
Has anyone had this problem and if so how did they overcome it? No time for major work to the flange faces, so the solution must be with the gasket itself.
In anticipation
Thanks
Steve McKenzie
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