| 摘要 |
<p>The total of the lengths (24,28) of the sections (22,26) either side of the heated section (12) is greater than the length (16) of the heated section. The total insertion length (34) is at least 1.4, preferably 1.7, times greater than the sleeve diameter (18). Other preferred proportions are also specified and there are correction factors for diameters other than 50 mm.</p> |
