Pressure maintaining valves

Pressure maintaining valves relieve to pressure in the line between pump and tool but maintain a pre-selected residual pressure (closing pressure) so that the build up to operating pressure is fast the next time the tool is actuated:

 
DHV 2

DHV 2
Operating pressure:
max 26,100 psi
Opening pressure: 1900 psi
Closing pressure: 145 psi

DHV 4

DHV 4
Operating pressure: max 43,500 psi
Opening pressure: 1900 psi
Closing pressure: 870 psi

DHV 5

DHV 5
Operating pressure:
max 43,500 psi
Opening pressure: 1900 psi
Closing pressure: 870 psi