SECTION III – INSPECTION 检查（七）-过滤器气泡点检查

K.Bubble Point Check for Filters

过滤器气泡点检查

(1) Perform bubble point test on filter in accordance with MIL-F-5504B.

根据MIL-F-5504B对过滤器进行气泡点测试。

• (a) The largest pore size of filter media can be experimentally determined by a Bubble Point Test. This is accomplished by measuring the pressure necessary to force air through media submerged in a known fluid. The surface tension of the fluid covering each pore prevents an indiscriminate permeation of the element.
• 过滤器介质的最大孔径可通过气泡点测试实验确定。具体方法是测量迫使空气通过浸没在已知流体中的介质所需的压力。覆盖每个孔的流体的表面张力可防止元件无差别渗透。
• (b) The Bubble Point Test apparatus shall be similar to that illustrated in . A filter element is submerged approximately 0.5 inch (12.7 mm) below the surface of a test fluid. The media is subjected to air pressure, which is increased in small steps until bubbles emanate from a point on the media surface.
• 气泡点测试装置应与图示装置类似。将滤元浸没在测试液表面以下约0.5英寸（12.7毫米）处。对滤元施加气压，并逐步增加气压，直到气泡从滤元表面上的某一点冒出。
• (c) The element is rotated 360 degrees about its longitudinal axis at each increment of air pressure so the entire element can be observed for the appearance of the first bubble, at which time the manometer reading is taken. The pore size is inversely proportional to the pressure at the point the bubble appears and is determined by the following formula:
• 每次增加空气压力时，元件围绕其纵向轴旋转360度，以便观察整个元件中第一个气泡的出现，此时记录压力计读数。孔径与气泡出现点的压力成反比，可用以下公式计算：
• Pore Size-Microns =【Fluid Constant, microns / in. H20】/【Fluid Pressure – Depth between fluid surface and media (in. H20】
• 孔径-微米=【流体常数，微米/英寸。H20】/【流体压力-流体表面与介质之间的深度（英寸。H20】
• (d) Test fluids most commonly used are Solox 190, ethyl alcohol, methyl alcohol, and red oil (MIL-H-5606). Red oil (MIL-H-5606) is used when paper media is being tested to prevent swelling or other damage to the media. Constants for various test fluids have been determined as follows:
• 最常用的测试液体有Solox 190、乙醇、甲醇和红油（MIL-H-5606）。当测试纸质介质时，使用红油（MIL-H-5606）以防止介质膨胀或受到其他损害。各种测试液体的常数如下：

• 

• Table 307.      Filtration Terms and Definitions 过滤术语和定义
  Term 术语	Explanation 解释
  Absolute 绝对	The minimum particle size which is collected 100 percent by the filter. 过滤器100%收集的最小颗粒尺寸。
  Affluent 流入	Fluid entering the filter. 进入过滤器的流体。
  Bubble Test 气泡测试	A method for locating and measuring the largest pore through a filter media by determining the minimum pressure required to force air through the media wetted by a specified fluid. 通过测定迫使空气通过被规定液体润湿的滤材所需的最小压力，来定位和测量滤材最大孔径的方法。
  Capacity-Dirt Holding 容量-纳污量	The amounts of specified test contaminant, usually measured by weight in grams, required to produce a given pressure drop under specified test conditions. 在规定的测试条件下产生给定的压降所需的特定测试污染物的量，通常以克为单位。
  Capacity-lnput 容量-输入	Refer to capacity-dirt holding. 参见容量-纳污量。
  Configuration 结构	The shape of the filter housing. 滤材外壳的形状。
  Contaminant 污染物	The foreign matter or particles in a fluid. 流体中的异物或颗粒。
  Cryogenics 低温	The science of super cold liquids such as liquid oxygen, liquid nitrogen, and liquid hydrogen. 超低温液体（如液氧、液氮和液氢）的科学。
  Effluent 流出物	Fluid that passes a filter. 通过过滤器的流体。
  Element 滤芯	Filter media and support as used in the filter assembly.  Characterized by construction, pleating configuration, and size. 过滤器组件中使用的过滤介质和支撑。以结构、褶皱配置和尺寸为特征。
  Filter 过滤器	The filter assembly, consisting of a housing and element. 由外壳和滤芯组成的过滤器组件。
  Filter Area-Effective 过滤面积效率	The area of media that is useable for filtration. 可用于过滤的介质面积。
  Filtration-Degree of 过滤度	The level of cleanliness of a fluid measured in terms of microns. 以微米为单位测量的流体清洁度。
  Filtration-Depth Type 过滤深度类型	Filtration which is accomplished in depth.  The actual pore size of a media may be larger than the desired degree of filtration, but because of its depth, it provides a tortuous path with many entrapments to catch foreign particles. 深度过滤。介质的实际孔径可能大于所需的过滤度，但由于其深度，它提供了曲折的路径，有许多陷阱来捕获外来颗粒。
  Filtration-Edge Type 边缘过滤类型	Fluid filters comprised of notched, flat discs or wires of trapezoidal, triangular, or related cross section where contaminants are entrapped at the edges of the media. 流体过滤器由带凹口的扁平圆盘或梯形、三角形或类似截面的金属丝组成，污染物被截留在介质边缘。
  Flow Rate 流速	The rate at which a fluid or gas is passed through a filter or system. 流体或气体通过过滤器或系统的速度。
  Line Size 管路尺寸	The type and size of fluid line used in a system. 系统中使用的流体管路的类型和尺寸。
  LOX 液氧	Liquid oxygen. 液态氧。
  LOX Cleaning LOX 清洁	The process of degreasing or making a component completely free of any hydrocarbons and foreign particles. 脱脂或使部件完全不含任何碳氢化合物和外来颗粒的过程。
  Media 介质	A material or controlled pore size or mass through which a fluid is passed to remove foreign particles held in suspension.  A part of the filter element. 一种材料或受控孔径或质量，流体通过它去除悬浮的外来颗粒。过滤器元件的一部分。
  Metal-Sintered 金属烧结	Porous metals made of powdered stainless steel, nickel, bronze, nickel silver, gold, silver, or other metals. 由不锈钢、镍、青铜、镍银、金、银或其他金属粉末制成的多孔金属。
  Micron 微米	One millionth of a meter or 0.000039 of an inch (0.00099 mm). 百万分之一米或0.000039英寸（0.00099毫米）。
  Migration-Abrasion 迁移-磨损	Dirt, generated by poorly designed parts that rub together and wear during vibration or shock, which enters the system fluid stream. 由设计不良的零件在振动或冲击期间摩擦和磨损而产生的污垢，进入系统流体。
  Migration-Media 迁移-介质	Break away of the filter material, which travels downstream. 滤材脱离，流向下游。
  Nominal 标称	An adjective relating to contaminant particle size.  Filters are normally assigned a nominal efficiency rating which implies that a given percentage of nominal size particles, or those of greater size, will be removed by the filter when tested  with a specified test contaminant under specified test conditions.  In assigning a nominal rating to a filter media, glass beads and AC Fine Test Dust are usually  specified as the test contaminant. 形容词与污染物颗粒大小相关。过滤器通常被赋予一个名义效率等级，这意味着在特定测试条件下，使用指定的测试污染物进行测试时，过滤器将去除一定比例的名义尺寸颗粒或更大尺寸的颗粒。在为过滤介质分配名义等级时，通常会指定玻璃珠和AC细测试尘作为测试污染物。
  Pressure-Burst 压力-爆破	The maximum design condition of the housing before failure. 外壳在失效前的最大设计条件。
  Pressure Drop-Clean 压降-清洁	The differential pressure drop across a clean filter at rated flow measured in pounds per square inch. 在额定流量下，清洁过滤器上的压降差，以磅/平方英寸为单位。
  Pressure Drop-Maximum Allowable 压降-最大允许	The maximum pressure differential of a filter under specified fluid and flow conditions. 在规定的流体和流量下，过滤器最大压差
  Pressure-Maximum Differential 压力-最大压差	The highest pressure differential which filter element is required to withstand without failure or collapse. 滤芯在不发生故障或塌陷的情况下需要承受的最大压差。
  Pressure-Maximum Operating 压力-最大操作	The maximum operating pressure through the system. 系统中的最大操作压力。
  Pressure-Operating 压力-操作	The normal pressure at which fluid or gas moves through a system. 流体或气体在系统中流动时的正常压力。
  Pressure-Proof 耐压	The maximum pressure that a filter can withstand without damage or leakage of the media. 过滤器在介质无损坏或泄漏的情况下可承受的最大压力。
  Pressure-Surge 压力波动	The peak system pressure experienced because of varied operating conditions, such as initial start up. 由于初始启动等各种操作条件而导致的系统峰值压力。
  Service Life 使用寿命	The length of time a filter will remain on stream before it exceeds the maximum allowable pressure drop. 过滤器在超过最大允许压降之前可连续工作的时间长度。