I have experimented with a selfmade insulation symbol pattern. It was intended to be used as a hatch pattern. But unfortunately LibreCAD does not allow the origin of a hatch to be shifted so it can't be aligned to within a certain area.
It can be used though if you fabricate stripes of multiple elements of it, which you scale, rotate, copy, cut and shift to your needs.
welldaemm1.dxfYou can put it into your hatch pattern folder and make hatch patches of it, then explode the hatch so you can move it around. Or open the file directly and copy and paste the pattern into the desired drawing or import it as a block.