Abstract: The invention relates to a radiation curable composition including a polyester urethane (meth)acrylate oligomer prepared from ortho-carboxylic polyester polyols, where the composition, after cure, has a secant modulus greater than about 600 MPa and an elongation at break of at least about 10%. The invention also relates to coated optical fibers and optical fiber ribbon including at least one coating derived from this composition, and to a process of making these coated optical fibers.

Abstract: Optical fiber coatings are disclosed having excellent ribbon stripping and adhesion behavior. The coatings are radiation-curable. The excellent stripping and adhesion behavior can be achieved by several means which include by use of additives, by use of radiation-curable oligomers having higher molecular weight, or by use of coatings having certain thermal properties. Combination of means can be employed. Stripping behavior can be measured by crack propagation and fiber friction measurements.

Abstract: A venting system for gas fired heating plants including a diverter box, conduit means for conducting gas from one heating plant upwardly in one leg of an inverted U pattern and downwardly into the second leg of such pattern while admitting air at the bottom of the box to form a heat lock to restrict the flow of air in this pattern, and a second conduit means for conducting gas from a second heating plant upwardly and then downwardly of the second leg of the pattern for the first heating plant to a level at which gas may be passed within the box from the inlet to the outlet of the box, thus providing a structure which avoids the blowing out of the pilot flame in one or another of the heating plants.