Parker Contamination Standards Guide

About this manual

This guide provides engineers, technicians, and quality‑control personnel with widely‑used cleanliness specification levels for hydraulic and fuel fluids. It includes ISO 4406:1999 codes, suggested acceptable contamination levels, and comparison tables for ISO, NAS, SAE, GOST and NAV AIR standards.

The document also promotes Parker’s free HFDE Condition Monitoring app for iPhone, iPad and iPod Touch, which offers an ISO cleanliness calculator and a frequency calculator to help reduce equipment downtime. Product solutions such as portable particle counters and filter selectors are described at the end of the guide.

What's inside

• Introduction
• Contamination basics
• ISO 4406:1999 codes (hydraulic fluid contamination)
• Suggested acceptable contamination levels
• ISO codes (fuel contamination)
• NAS 1638 table
• SAE AS4059 rev E table
• PPM Conversion table

Frequently asked questions

What app does Parker offer for fluid condition monitoring?

Parker offers a free HFDE Condition Monitoring app for iPhone, iPad, and iPod Touch that includes an ISO cleanliness calculator and a frequency calculator.

What particle size range is most damaging in hydraulic systems?

The most damaging contaminants in hydraulic systems are normally between 6 and 14 microns.