عنصر أنبوبي صلب يناسب بين المحمل وغطاءه، تم تصميمه في المقام الأول كسطح تآكل قابل للاستبدال داخل الجدار الداخلي للغطاء.
"76301-ps21201 specification (includes engineering type bulletins, brochures,etc., that reflect specification type data in specification format; excludes commercial catalogs, industry directories, and similar trade publications, reflecting general type data on certain environmental and performance requirements and test conditions that are shown as "typical", "average", "nominal", etc.)." test data document, steel,mil-s-5000,o/a; id at internal flange,2.28 in. min and 2.34 in. max; 0.045 in. min and 0.065 in. max internal flange w; 2.4409 in. min and 2.4413 in. max id; 0.515 in. min and 0.565 in. max o/a w; external flange at opposite end of internal flange; 2.90 in. min and 2.96 in. max external flange od; 0.045 in. min and 0.065 in. max external flange w; 2.5812 in. min and 2.5817 in. max body od; black oxide,ams 2485,o/a surf. fin.; 34.0 min and 39.0 max rockwell hardness general characteristics item description