The figures are differential counts, and the NAS class is usually reported as a single figure >5µm. >15µm. >25µm. >50µm. >µm. Size code. A. B. C. D. E. F. 76 SAE AS rev E Table Particle Contamination Level by Class. The SAE aerospace standard (AS) ASD defines cleanliness classes for particulate contamination of hydraulic fluids and includes methods of reporting. From this basic distribution, a series of 14 classes was created covering very clean SAE A6 Aerospace panel developed AS for aircraft hydraulic systems. . instance NAS Class 6, can be swapped to AS Class 6B through F.
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Is NAS dead? Engineering designs that include a high percentage of procured-in components and sub-modules from external companies is the responsibility of a broad lcass stakeholder network.
Click here to see Table 3.
What Happened to NAS 1638?
NAS saw widespread acceptance in the s and s by industries where reliability was a prerequisite, in areas such as offshore oil production, iron and steel industries, etc. The reason for this is not entirely clear but it cass thought to be the need to separate old and new APC data. No coding system existed at the time for completed systems, so it was logical that it would be applied in this area. The introduction of the APC during the s sae as 4059 class 6b-f the measurement of the size distribution of dirt particles in a hydraulic system.
APC users are recommended to switch to the new AS standard. APC users are recommended to switch to the new standards. Oklahoma State University, under the direction of Prof. Students Click Here Join Us!
Equally, sizes that are not critical can be omitted. There are three reporting options:. The author recommends a use of AS system for commonality using sizes B to F, and relating the particle counts to sae as 4059 class 6b-f of the components wetted volume.
Another aspect that is giving rise for concern is the statement in clause 6. It converts the particle counts at various size ranges into convenient broad-base classes. National Aerospace Standard NAS 1 is a particulate contami-nation coding system used in the fluid power industry to simplify the commu- nication of data from particle counters.
This was based upon the size distribution of A. Another criticism of NAS was that there was little 6b-v on how to use or apply it. If sae as 4059 class 6b-f obtain the latest issue of NAS you will find the following statements: As products get more complex, so do the supply networks that build them. sae as 4059 class 6b-f
SAE AS equivalent ISO/DIN – SAE (Automotive) Code Issues – Eng-Tips
One aspect of the change, which may be a little unclear, is that of component cleanliness – the scope of the original NAS document. NAS can be used for existing systems where correlation with earlier data is necessary. The basis of the code is seen in Table aw.
This, and the fact that all five of the size ranges were not needed, led to the development of ISO in the early s. Join your peers on the Internet’s largest technical engineering professional sae as 4059 class 6b-f. About the Author Mike Day. The reasoning behind this is not entirely clear, but thought to be to separate old and new APC data.
However, users are encouraged to change to AS as soon as possible sae as 4059 class 6b-f that everyone is speaking the same language.
What Happened to NAS ?
The method of counting the particles referenced the optical microscope method defined sae as 4059 class 6b-f ARP 4simply because this was the only method in existence at the time. This distribution was based on particle contamination inside delivered aircraft hydraulic components in the s.
This is a result of recent changes to the ISO contamination standards for automatic particle counter APC calibration 3which necessitated the review of NAS and resulted in its withdrawal for newly designed systems. Addressing Challenges of Online Monitoring.
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Click Here to join Eng-Tips and talk with other members! Because this situation could cause an uproar within the industry when companies would have to change specifications, the ISO committee decided to take the road sae as 4059 class 6b-f least resistance and selected new size descriptors that would give the same particle counts while retaining integer sizes. From this basic distribution, a series of 14 classes was created covering very clean to very dirty levels, where the interval between each class is double the contamination level.
Current Issue Archive Advertise. The author considers AS to be a significant advance over NAS because it offers many benefits. Close this window and log in. Digital transformation may be ax most frequently misunderstood and misused term in business discourse today. Product innovation is speeding up.
This principle is a feature of many of the classes that have developed since. Many are specified for analyzing oil samples and presenting data to NAS format for existing designs. This concept gives AS much sae as 4059 class 6b-f flexibility than was possible with NAS because it is often the control of the cleanliness level that specifiers require sae as 4059 class 6b-f than a fixed distribution; for example, they can specify improved control over critical sizes or relax controls over those that are not.
This subsequently became de facto ISO I’m guessing it’s equivalent to Nas c,ass ISO