Sun has introduced a new family of combination valve cartridges that incorporate a relief and check function into a single cartridge. And since both functions exist in one, only one cavity is required. This provides for a simpler system with fewer mechanical connections to maintain. As with other Sun relief products, several mounting configurations will be available, including pump mounting.
These 40 lpm hybrid cartridges are available in two different styles: relief-before-check and relief-after-check.
Relief-before-check
The relief-before-check cartridge can be used to provide pump isolation and relief protection in single or multiple pump circuits. It is available in three configurations.
* Direct-acting (3-port)
The HRDA cartridge incorporates a direct-acting relief tee’d in before a check function. When the pressure at the inlet (port 2) reaches the relief valve setting, the valve starts to open to tank (port 3), throttling flow to limit the pressure rise. The check valve flow is from the inlet (port 2) to the system port (port 1). These valves are smooth and quiet, essentially zero leak, dirt tolerant, immune to silting and are very fast.
* Ventable, pilot operated, balanced piston (4-port)
The HVCA cartridge incorporates a ventable, pilot-operated, balanced piston relief tee’d in before a check function. When the pressure at the inlet (port 2) reaches the relief valve setting, the valve starts to open to tank (port 3), throttling flow to regulate the pressure. The check valve flow is from the inlet (port 2) to the system port (port 1). The valve includes a vent port (port 4) that connects between the main piston and pilot stage to provide for remote control or unloading by other pilot or 2-way valves. These valves are accurate, have low pressure rise vs. flow, are smooth, quiet, and are moderately fast.
* Ventable, pilot operated, balanced piston relief main stage with integral T-8A control cavity
The HVCA-8 cartridge incorporates a normally closed, balanced piston modulating element tee’d in before a check function. The valve incorporates an integral pilot control cavity. The pilot control cavity will accept any T-8A pressure control cartridge. When the pressure at the inlet (port 2) reaches the pilot control valve setting, the modulating element starts to open to tank (port 3), throttling flow to regulate the pressure. The T-8A pilot section is drained to port 4. The check valve flow is from the inlet (port 2) to the system port (port1).
This cartridge is designed to accept a pilot control valve into the T-8A cavity located in the hex end of the cartridge. An air-piloted relief or proportional pilot control valve is recommended for a wider range of control.
Relief-after-check
The relief-after-check cartridge provides protection on the system side of the circuit and is only available in direct-acting configuration.
The HRDB cartridge incorporates a direct-acting relief tee’d in after a check function. The check valve flow is from the inlet (port 2) to the system port (port1). When the pressure in the system (port 1) reaches the relief valve setting, the valve starts to open to tank (port 3), throttling flow to limit the pressure rise. These valves are smooth and quiet, essentially zero-leak, dirt-tolerant, immune to silting and are very fast.
For more information contact Fritz Kern, Axiom Hydraulics, +27 (0)11 334 3068, [email protected], www.axiom.org.za
| Tel: | +27 11 334 3068 |
| Email: | [email protected] |
| www: | www.axiomsa.co.za |
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