本SAE航空航天信息报告（AIR）介绍了飞机整体式油箱密封的首选设计、组装和维修实践，包括对应用的油箱密封进行返工。它介绍了目前在实践中发现的整体式油箱的工程设计，并讨论了生产可靠密封系统的最实用和最保守的方法。尽管本AIR介绍了整体式油箱密封的实践，本报告中介绍的实践是贯穿整个密封过程的实践，包括压力和环境飞机密封。 最佳密封的设计偏好不在本文件的范围内。这种讨论可以在美国空军（USAF）赞助的报告AFWAL-TR-87-3078《飞机整体油箱设计手册》中找到。油箱密封过程的主要目标是生产一种无泄漏和耐腐蚀的密封飞机，尤其是在紧固件位置，在每架飞机寿命预期的环境和操作条件下。影响这一过程结果的因素包括:a基本设计在多大程度上有利于良好的密封（需要考虑的关键设计因素包括可达性和最小移动量等）。 b密封剂的选择，在哪里使用，以及如何使用。c如何制备好基底表面。d密封剂圆角尺寸是否适合飞机配置和飞行动力学。密封剂必须对流体和热环境具有一定的抵抗力。工程保险程度，即在密封剂粘合表面上使用增粘剂，在密封剂上应用有机面漆，油箱适当排水等-用于降低技术风险。有效和高效地密封飞机油箱是商用和军用飞机设计的首要考虑因素。 注意，油箱内的角密封被认为是主要的燃料屏障密封。腐蚀控制几乎同样重要。例如，通常认为接合表面密封的主要目的是腐蚀控制。接合面密封不被视为主要的燃料屏障密封，粘合剂粘合系统除外；然而，接合面密封作为二次燃料屏障密封确实发挥着极其重要的作用。它限制了泄漏路径的长度，是一种永久、稳定、受保护且基本上不可移动的密封件，夹在两个配合面之间。 强烈建议广泛使用接合面密封。密封原理因行业和政府而异。然而，正如第3.1条所述，存在的一致性远大于争议。如果考虑到生产周期时间和成本，特定的油箱密封方法显然更可靠，那么它将被确定为首选方法。本报告无法具体说明许多单独设计中的每一种。然而，本报告建议使用可刷、可挤压和可滚动密封剂的首选做法；它还指出了在接缝、接头、紧固件头部、空隙、接合面和所有设计通用的配置类型中应用密封剂时更理想的轮廓和厚度。 本文件文本和图中使用的尺寸，即使使用了“必须”或“应”，也是典型的，但在飞机平台上并不通用。个别飞机制造商，无论是在设计、材料选择还是风险承受能力方面，都可能有略微不同的尺寸或公差要求。本报告基于专门从事飞机密封的广泛工程专家的技术意见。用户应考虑本报告提供的工程要求和选项；然后从一个稍微知情的位置制定一个单独的行动方案（或计划）。

This SAE Aerospace Information Report (AIR) presents preferred design, assembly, and repair practices for sealing of aircraft integral fuel tanks, including rework of applied fuel tank seals. It addresses engineering designs for integral fuel tanks as they are currently found in practice and discusses the most practical and conservative methods for producing a reliable, sealed system.Although this AIR presents practices for sealing of integral fuel tanks, the practices presented within this report are practices that are carried throughout sealing that include both pressure and environmental aircraft sealing.Design preferences for optimum sealing are not within the scope of this document. Such discussions can be found in the United States Air Force (USAF) sponsored report AFWAL-TR-87-3078, “Aircraft Integral Fuel Tank Design Handbook.”Key objectives of the fuel tank sealing process are to produce a sealing plane that is leak-free and corrosion resistant, especially at fastener locations, at environmental and operational conditions expected for the life of each aircraft. Factors that can influence the outcome of this process are:aHow well the basic design lends itself to good sealing (key design factors to consider include accessibility and minimal movement, among others).bThe choice of sealant, where it is applied, and how it is applied.cHow good substrate surfaces are prepared.dWhether sealant fillet dimensions are optimum for aircraft configuration and flight dynamics.eThe degree of resistance sealants must have to fluid and thermal environments.fThe degree of engineering insurance—i.e., application of adhesion promoters to sealant bond surfaces, application of organic topcoats over sealants, proper drainage of the fuel tank, etc.—employed for technical risk reduction.Effective and efficient sealing of aircraft fuel tanks are prime considerations in both commercial and military aircraft designs. Note, fillet seals inside fuel tanks are considered to be the primary fuel barrier seals.Of nearly equal importance is corrosion control. It is generally accepted, for example, that a major objective of faying surface sealing is corrosion control. The faying-surface seal is not considered to be a primary fuel barrier seal, except in adhesive-bonded systems; the faying surface seal, however, does play an extremely important role as a secondary fuel barrier seal. It limits the length of a leak path and is a permanent, stable, protected, and essentially non-dislodgeable seal that is sandwiched between two mating surfaces. Extensive use of faying-surface sealing is highly recommended.Sealing philosophies differ within industry and government. However, as stated in3.1, there is much greater agreement than dispute. If a particular fuel tank sealing approach appears to be clearly more reliable, keeping production cycle time and costs in mind, it will be identified as a preferred method.This report cannot specifically address each of the many individual designs. However, this report recommends preferred practices in the application of brushable, extrudable, and rollable sealants; it also points out the more desirable contours and thicknesses to be used in the application of sealant in seams, joints, fastener heads, voids, in faying surfaces, and in types of configurations that are common to all designs. Dimensions used in the text and figures of this document, even where the words “must” or “shall” are used, are typical but not universal across aircraft platforms. Individual aircraft manufacturers, whether by design, material selection, or risk tolerance, may have slightly different dimensional or tolerance requirements.This report is based on technical opinions from a broad cross-section of engineering experts who specialize in aircraft sealing.The user should consider the engineering requirements and options provided by this report; then develop an individual course (or plan) of action from a somewhat more informed position.