Pipe Insulation is thermal or acoustic insulation used on pipework. A hydraulic pressure test on the boiler and pipework may also be called for. Lead burning is "not" used as part of plumbing work for installed pipework. Used unskillfully, they can also damage plastic pipework and even copper tubing. Alternatively a condensate pump may be employed where space for such gravity pipework is limited. These had inconspicuous condensing apparatus with the pipework hidden from view. The location of pipework also influences the selection of insulation thickness. Much of the internal pipework was steel rather than copper. These typically comprise slotted uPVC pipework surrounded by single sized gravel. GLC/MS facilities can detect micro-organic contaminants from the pipework and glands. Radon decays to form solid radioisotopes that form coatings on the inside of pipework. The radon decays to form solid radioisotopes which form coatings on the inside of pipework. This protects system components, particularly pipework, from both potentially destructive forces. All of the old pipework and casework was not restored and retained. Gravity bleeding is often not effective because of the layout of the clutch pipework.