第1部分:密封接头排放和泄漏:PPMV和密封产品质量泄漏率之间的相关性这些项目记录了精确的实验室泄漏率测量与EPA方法21协议之间的相关性，该协议用于使用标准装袋技术测量氦气和甲烷的PPMV（百万分体积）。使用带有柔性石墨板垫片的仪表化NPS 4 600级螺栓连接夹具。对氦气和甲烷中的大流量至极低流量进行了研究，垫圈承受的应力范围为1000至15000 psi（8.至103 MPa），垫圈应力和压力范围为50至800 psi（0.35至8.5Mpa）。结论是标准EPA装袋法对于PPMV排放测量是准确的，作者还质疑在开放环境中嗅探法兰是否是可靠的排放测量方法。 对电厂工程师来说，更重要的是确认EPA方法21流量公式的可靠性，作为一种将现场PPMV测量值与报告的实验室泄漏结果进行比较的方法，以帮助选择垫片。第2部分:密封接头排放和泄漏:PTFE基密封垫材料的长时间机械性能在项目96-12之前，PTFE密封垫材料的泄漏、松弛和爆裂性能测试数据相对较短。通过ATRS和ARLA测试，高温暴露的现有暴露时间最多为16天。长期暴露在高温负荷下的影响，例如在运行中的电厂，引发了几个有充分根据的问题。例如，是否存在渐进但持续的爬行- 松弛，还是泄漏随时间增加或减少？此外，随着时间的推移，是否会发生影响排放的退化或硬化或其他物理效应？在这个项目中，至少对于研究的两种典型材料，研究人员发现了明显的趋势。令一些人惊讶的是，答案是，长达一年的接触没有明显的不良影响。这两种材料都没有经历有意义的蠕变或厚度变化，并且都保持了基本稳定的泄漏率。第3部分:密封接头排放和泄漏:对金属增强柔性石墨板材料高温性能的联合工作条件的探索性调查项目95-24以参数化的形式探讨了委员会就之前的ATRS和ARLA垫片筛选项目提出的一些问题。 在能够模拟各种真实接头的多功能试验台上，使用更精确、更全面的HOTT（热操作密封性试验）探索了对所含介质泄漏的影响、高内部压力与低内部压力、初始阀座应力和接头刚度等问题。HOTT测试跟踪实时泄漏和松弛，同时模拟典型接头以及ATRS和ARLA测试夹具的刚度。暴露在800 psi（5.5 MPa）空气和950°F（510°C）环境中的片状石墨垫片是基本情况，因为研究了压力、硬度、初始应力、流体类型和氧化抑制剂的存在，以确定降解和泄漏是否减少或加剧。研究结果表明，压力、介质和接头刚度对降解率的影响最大，而初始垫片应力水平（低于8100 psi）以及令人惊讶的是，氧化抑制剂的存在对降解率的影响要小得多。 效应建议在其他初始荷载和较低压力下使用空气进行额外测试，以确认这些观察结果。重要的是，调查告诉我们，简单的ATRS/HATR测试仍然是垫圈性能的可接受筛选指标，并确认了PVRC项目91-8和93-3中针对柔性石墨基板材制定的鉴定协议，适用于广泛的实际应用。

Part 1: Gasketed Joint Emissions and Leakage: Correlation Between PPMV and Mass Leakage Rate of Gasketing ProductsThese projects document the correlation of precise laboratory leak rate measurements with the EPA Method 21 protocol for PPMV (parts per million by volume) measurements with Helium and Methane using the standard bagging technique. An instrumented NPS 4 class 600 bolted joint fixture with a flexible graphite sheet gasket was used. Large to very low flow rates in Helium and Methane were investigated with the gasket subjected to a stress range of 1000 to 15000 psi (8. to 103 MPa) gasket stress and pressures from 50 to 800 psi (0.35 to 8.5Mpa). Concluding that the standard EPA bagging method is accurate for PPMV emission measurements, the authors also question sniffing around a flange in an open environment as a reliable method of emissions measurement. More important to plant engineers is confirming the reliability of EPA Method 21 flow formula as a means to compare field PPMV measurements with reported laboratory leakage results as an aid to gasket selection.Part 2: Gasketed Joint Emissions and Leakage: Long Duration Mechanical Performance of PTFE Based Gasket MaterialsPrior to Project 96-12 only relatively short time PTFE gasket material test data on leakage, relaxation and blowout behavior was available for PTFE gasket materials. Existing exposures for elevated temperature exposures by means of ATRS and ARLA tests were at most 16 days. The effect of long-term exposures under load at elevated temperature, such as in operating plants, begged several well-founded questions. For example, is there gradual but continuing creep-relaxation, or does leakage increase or decrease over time? Also, does degradation or hardening or other physical effects occur over time that affects emissions? In this project, at least for the two typical materials studied, the investigators found clear trends. The answer, surprising to some, is that the yearlong exposure had no significant adverse effect. Neither of the materials experienced meaningful creep, or thickness change, and both maintained an essentially steady leak rate.Part 3: Gasketed Joint Emissions and Leakage: Exploratory Investigation of Joint Working Conditions on the Elevated Temperature Behaviour of Metal Reinforced Flexible Graphite Sheet MaterialsProject 95-24 explores in a parametric format a number of questions raised by the committee about predecessor ATRS and ARLA gasket screening projects. Issues such as the effect on leakage of the contained media, high vs. low internal pressure, initial seating stress and joint rigidity were explored using the more precise and comprehensive HOTT (Hot Operating Tightness Test) in a versatile test rig capable of mimicking a variety of real joints. The HOTT test tracks real-time leakage and relaxation while simulating the rigidity of typical joints and the ATRS and ARLA test fixtures. Sheet graphite gaskets exposed to 800 psi (5.5 MPa) air and 950°F (510°C) were the base case as, pressure, rigidity, initial stress, fluid type and the presence of oxidation inhibitor were investigated to determine whether degradation and leakage were reduced or aggravated. Findings indicate that pressure, media and joint rigidity are the most significant on the degradation rate while initial gasket stress levels (below 8100 psi) and, surprisingly, the presence an oxidation inhibitor are much less significant. Effect. Additional testing performed under other initial loads and with air at lower pressures is recommended to confirm these observations. Importantly the investigation tells us that the simple ATRS/HATR test remains an acceptable screening indicator of gasket behavior and confirms the qualification protocols developed in PVRC Projects 91-8 and 93-3 for flexible graphite based sheet materials for a broad range of real world applications.