SAE J747_199005

This SAE Standard applies to hydraulic directional control valves as applied to self-propelled work machines referenced in SAE J1116. It describes a laboratory test procedure for evaluating: a Flow versus pressure drop b Leakage rate c Operating effort d Metering characteristics versus spool travel, pilot pressure, or electrical current e Relief valve characteristics The document applies to single and multiple section hydraulic directional control valves. This document illustrates axial, manually operated valves although the test procedure is applicable to other input forms such as rotary actuation, electric current, hydraulic or pneumatic pressure. NOTE—Performance characteristics such as metering hysteresis or dynamic response may have a significant effect on some of these tests. In hydraulic fluid power systems, power is transmitted and controlled through a liquid under pressure within an enclosed circuit. The hydraulic fluid power control valve is used to direct and control the fluid in the circuit to achieve the desired functions and flow of the fluid. The pressure drop, leakage rate, operating effort, metering characteristics and relief valve characteristics are indications of the ability of the control valve to perform the desired functions. The test procedure has been a recommended practice since 1956, last revised in 1975 and a five year review was started in 1982. Since several documents have been written which describe certain tests in more detail, they have been incorporated into this procedure. Also, the wording has been revised to expand the scope of the procedure to include other input forms in addition to direct manual operation. After a number of rewrites and input from manufacturers and end users, the revised test procedure was balloted in ORMTC SC4 on July 16, 1987, with fifteen approvals, one disapproval, and seven no replies. The subcommittee also recommended to upgrade the document to a standard and to submit the document to ANSI. The document has been revised to resolve the disapproval and include revisions from comments on the approval ballots.