Made as a sandwich of corrugated wood cellulose discs rotated at 90° to the next and bonded together.
由多个波纹状木质纤维片组成，纹路方向正交90°相叠加，就如三明治一样。
This gives a series of connected surfaces with corrugations running north-south and east-west.
如此一系列纹路方向正交的表面相连接。
Two-disc filter sandwich 两片滤片 Filtered oil returned to the oil circuit 已过滤的油回到回路
Unfiltered oil enters under pressure 未过滤油在压力下进入
Outer filter housing 过滤器外壳 Function 功能
Particles pass through the filter maze until they are trapped 颗粒物进入过滤器，直到它们被截留在滤片上
The CJCTM depth filter has a contamination holding capacity of approximately 2 L and only needs replacing every 12 months.
CJCTM深度型过滤器拥有大约2L的纳污能力，并且只需要每12个月更换一次。 Depth filters filter effectively down to 3 μm absolute. 深度型过滤器能有效的过滤小到3微米的颗粒。
Depth filters absorb water and resins (oxidation residuals) 深度过滤器还可吸收水份和树脂（氧化残留物）
Basic filtration definitions 基本的过滤定义
Nominal filtration 标准过滤精度
Ratings are estimated values, indicating a particulate size range at which the filter is claimed to remove a given percentage. There is no standard for this, so consequently, different products/makes cannot be compared.
29
评定标准是一个估计值，表明过滤器标称能够去除的百分比含量中所涵盖的微粒的尺寸范围。对此没有一个明确标准，因不同的产品而无法比较。
Operating pressure and concentration of contaminants will affect the retention efficiency of nominal rated filters.
操作压力和污染物的浓度会影响标准过滤精度的过滤器的去除效率。
Absolute filtration 绝对过滤精度
Ratings describe the pore size, indicating the largest size of particle which can pass through the filter. The filter need to apply to a standard test method intended for filter usage.
评定标准描述了孔径大小，标明了可以通过过滤器的最大颗粒的大小，过滤器需要经过标准化的测试方式来实现过滤使用。
The rating of depth filters is often 3 micron absolute or less. The rating of surface filters varies according to the requirements of the components to be protected.
深度过滤器的精度通常是3微米或更小。表面型过滤器的过滤精度，根据要保护的元件的要求而有所不同。
Beta values
are describing filter efficiencies at a given particle size. The value is written ?x, where the “x” represents the particle size in question and the ? is the efficiency, e.g. ?3 = 75, which means that one out of 75 particles of 3 micron size will pass through the filter (1.3% passes though and 98.7% are retained in one pass).
Beta 值是以给出的颗粒尺寸来描述过滤器的过滤效率，写作?x，x表示颗粒尺寸，?是效率，
例如：?3 = 75，意思是75分之一的3微米的颗粒会通过过滤器（1.3%通过，98.7%在一次通过中被截留）
30
In order to find the Beta value, a standardised “Multipass test” is used, and the Beta value is calculated by the following formula:
为找出Beta值，通常应用一个标准化的“多次通过测试”，Beta值由下面的方式计算出来：
Fig. 12:图12：
Multipass test 多重通过的测试 Test filter 测试过滤器 Filter efficiency 过滤效率 Source: 来源： ISO Standards ISO标准
Dirt capacity 纳污容量
Dirt capacity is the quantity of contamination absorbed by the element when the saturation pressure is reached.
纳污容量是指当达到饱和压力时，滤芯的吸收污染物的数量。
This is measured in weight or volume. 这个数值用重量或体积衡量。 Filter by-pass valve 过滤器的旁路阀
The filter by-pass valve eliminates the filtration function by by-passing the full flow filter, e.g. a by-pass valve opens when the pressure drop over the filter is too high.
31
因为绕过全流量的过滤器，过滤器的旁路阀没有过滤功能。当压力在过滤器上损耗太大的时候，旁路阀会开启。
The oil flow then completely or partially passes by – and not through – the filter.
此时液流会全部或部分分流，而不通过过滤器。
A leaking by-pass vale has a devastating effect on the filter efficiency value.
旁路阀的泄漏会对过滤器的效率产生严重影响。
For off-line filters, the by-pass valve should be in the pump, connecting the pressure and suction ports.
对于离线过滤，旁路阀应在泵中，连接泵的压力油口和吸油口。
Fig. 13: By-pass valve
图13： 旁路阀
Installation methods 安装方法
Oil system diagram 油质系统图
Full-flow filtration 完全流量过滤
The total system flow passes through the filter. 系统的全部油液流经过滤器。
Only surface filter elements are applicable here. 仅有表面型过滤器用于此种情况。
32
