In Reply to: Re: The Hydraulic Oil Story posted by raVen on December 31, 2013 at 12:06:34:
As I said earlier the ISO hydraulic oil grade numbers are the nominal viscosity of the oil measured at the reference temperature of 40C. That is entirely unlike the SAE system where the grade numbers are totally arbitrary labels. The ISO system allows for a variance of +/- 10% from the nominal viscosity so an ISO 46 oil can be anywhere in the range of 41.4 to 50.6 inclusive.
There are also gaps between the ISO grades. The next heavier grade up from ISO 46 is ISO 68 which ranges from 61.2 to 74.8. Widman has the full DIN 51519 table of the ISO grades on their site.
The specification of 1500 PSI on the N-series hydraulic system is not oil dependent. It is the MAXIMUM hydraulic pressure the lift mechanism and plumbing is designed to handle. The expectation is the pump can and will deliver considerably more than 1500 PSI so a pressure relief valve is installed in the lift circuit to vent pressure @1500 PSI in the event the lift is overloaded. That is why you chainthe lift down to run a pressure test. I can tell you from first hand testing that an N-series pump in good mechanical condition and a leak free lift system can and will produce in excess of 1500 PSI using Premium UTF from TSC. I can also tell you that it will continue to do so even after extensive work on a hot summer day. There are also plenty of people who can tell you that a worn pump won't do that. I am sure they are correct.
TOH
Posting not permitted in the forum archives.<1388513700">