Parker RL4 Relief Valves are designed such that when the upstream pressure exceeds the closing force exerted by the spring, the lower stem opens, permitting flow through the valve. Flow through the valve increases proportionately to the increase in upstream pressure.
Features:
- Pressure settings are externally adjustable while the valve is in operation. Seven different spring ranges provide greater system sensitivity and enhanced performance.
- Manual override option with positive stem retraction is available for the full working pres- sures range. This option permits the user to relieve upstream pressure while maintaining the predeter- mined cracking pressure.
- Standard low friction synergistic coating of body bonnet improves crack and re-seal performance.
- Color coded springs and labels indicate spring cracking range.
- Back pressure has minimum effect on cracking pressure.
- Lock wire feature secures a given pressure setting.