墊片(gasket)是兩個物體之間的機械密封,通常以防止兩個物體之間受到壓力、腐蝕、和管路自然地熱脹冷縮泄漏。由于機械加工表面不可能完美,使用墊片即可填補不規則性。
一、按墊片(pian)材質分類(lei)
不同類型墊(dian)片(pian)材料見表5.3.1。
1. 非金屬墊(dian)(dian)(dian)片(non-metallic gasket),有石棉橡(xiang)膠(jiao)墊(dian)(dian)(dian)片、橡(xiang)膠(jiao)墊(dian)(dian)(dian)片、聚四氟乙烯墊(dian)(dian)(dian)片、合成(cheng)橡(xiang)膠(jiao)墊(dian)(dian)(dian)片、膨(peng)脹石墨、皮革等。非金屬包覆(fu)墊(dian)(dian)(dian)片(non-metallic jacket gasket)外包一(yi)層合成(cheng)樹脂等。
2. 半金屬墊(dian)片(pian)(semimetallic gasket)用金屬和(he)非金屬材料制成的(de)墊(dian)片(pian),如纏繞(rao)式墊(dian)片(pian)、金屬包覆墊(dian)片(pian)。
①. 纏(chan)繞式墊(dian)(dian)片(pian)(spiral wound gasket)由(you)V形或(huo)W形斷面的金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai)夾非金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai),金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai)與非金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai)螺旋纏(chan)繞成環(huan)(huan)(huan)形墊(dian)(dian)片(pian)。金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai)與非金(jin)(jin)(jin)屬(shu)(shu)帶(dai)(dai)交替(ti)纏(chan)繞,由(you)于其(qi)具有較好的彈性,廣泛用于石化(hua)、化(hua)工、電(dian)力等行(xing)業的法(fa)蘭密封結構中(zhong),根據(ju)具體部位,可在(zai)墊(dian)(dian)片(pian)的內層或(huo)外層加上(shang)鋼環(huan)(huan)(huan)來定(ding)位或(huo)加強(qiang)。內環(huan)(huan)(huan)(inner ring)是(shi)設置在(zai)纏(chan)繞式墊(dian)(dian)片(pian)內圈的金(jin)(jin)(jin)屬(shu)(shu)環(huan)(huan)(huan)。外環(huan)(huan)(huan)(outerring)是(shi)設置在(zai)纏(chan)繞式墊(dian)(dian)片(pian)外圈的金(jin)(jin)(jin)屬(shu)(shu)環(huan)(huan)(huan)。
②. 金(jin)屬包覆。
3. 金屬墊(dian)片(metallic gasket)是用鋼、鋁(lv)、銅、鎳或蒙乃爾合(he)金等(deng)金屬制成的墊(dian)片。
二(er)、按墊片形狀分類
按墊(dian)(dian)片(pian)形狀分類可(ke)分為: 環(huan)狀平墊(dian)(dian)片(pian)、復合型墊(dian)(dian)片(pian)、波紋型墊(dian)(dian)片(pian)、環(huan)狀墊(dian)(dian)片(pian)
不同形狀墊片如(ru)圖 5.3.1所示。