A three piece ball valve was specifically designed for high pressure systems at 5000 psi.
The actual operation in the field required 3000 cycles over a five year period. Acetal bearings had been used
previously but only lasted 2 years. Acetal has a lower compression strength than Vesconite Hilube.
To simulate field conditions in the laboratory, the test rig was run for 4 hrs continuously with 3000 cycles
executed in four hours.
The Vesconite Hilube bearing was tested at 4 times the working pressure. The bursting pressure is 10 400 psi
The actual test was conducted at 180 bar (18MPa). The torque before and after was 90 Nm.
The Vesconite Hilube bearings were inspected after the tests and showed no wear.
It was found that acetal showed a much higher turning differential force than Vesconite Hilube.
Vesconite Hilube has a much lower co-efficient of friction than acetal and avoids stick slip problems.