Submission material (manhole gasket)
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I have only recently started working in maintenance, and I need to keep track of the gaskets for manholes. The specifications for these manholes as indicated on the drawings are RF II S-35cm (w.d-1222) 450-1.6. Is it appropriate to use graphite wound gaskets with a diameter of dn450 and a pressure rating of PN2.5 (without rings)? Thank you!
RF Ⅱ S-35cm(w.d-1222) 450-1.6, where RF indicates that the sealing surface connection type is a flat connection； S-35cm, 450-1.6 refers to the description of an oval-shaped rotary cover with quick-opening access hatch; 1.6 represents the pressure rating ； W.D-1222 indicates that the gasket is intended for butt-welded flanges; it uses internally and externally reinforced gaskets, and a DN450, PN2.5 graphite wound gasket without an outer ring is absolutely not suitable. This is because planar sealing can only be achieved with gaskets that have an outer ring or those with both inner and outer rings. Since the layers in a wound gasket can easily separate from each other, tightening the bolts when using a gasket without an outer ring will damage the gasket, resulting in no proper sealing effect.:)
The specifications for manholes already include those for the manhole gaskets; d-1222 refers to the inner and outer rings, with the material being 1222. Its manhole standards comply with HG21514, and the corresponding gaskets should also be HG20610. See the standard for details
The sealing surface type is convex, and wound gaskets for both the inner and outer rings must be used; HG20610 or GB/T4622.2 are both suitable
Did the poster mention procurement? Here, we need to have the drawings provided.