UNCD® Powers Through Low-Lubricity Conditions:
One of the most common high wear applications for mechanical seals is pumping media with low-lubricity characteristics such as: hot water, light hydrocarbons, fluids with entrained gases. UNCD coated faces perform substantially better than conventional alternatives.
Test Results – Hot Water
UNCD faces exhibited almost no wear after 100 hours of severe service. In the same conditions, SiC faces exhibited extreme wear (well over 4,000 microinches of grooving) and seal leakage after 50-75 hours of operation. (250oF/121oC water at 100psig; ANSI pump; Multi-spring pusher seals).
Test Results – Entrained Gas
Diamond combinations ran an average of 67oF/37oC cooler than SiC/SiC pairings and exhibited substantially lower wear.
|ATTRIBUTE||SiC vs SiC||SiC vs UNCD||WC vs UNCD||UNCD vs UNCD|
|Test Duration||1.5 hrs||100 hrs||100 hrs||100 hrs|
|Seal Face Wear||906 μin||342 μin||30 μin||None|
|Avg. Temperature||140oF (60oC)||70oF (21.1oC)||69oF (20.6oC)||81oF (27.2oC)|
|Theoretical Wear Life||1.5 hrs||4.2 years||47.6 years||Infinite|
UNCD Performs During Pump Start-Up and Intermittent Dry Running
ADT has specifically designed UNCD to perform in intermittent dry running conditions. While absolute run times depend on a given set of conditions, the data shown on the right replicates typical severe conditions. UNCD tested in customer trials showed up to 20 times longer MTBF
In dry running cycle testing UNCD running against a SiC counterface continues to successfully seal after having been exposed to 35 dry running cycles of 5 minutes each. SiC running against a SiC counterface fails consistently after the first 90 seconds of dry running.