SUN HYDRAULICS
SCIALDN

***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Sun Hydraulics directly.***
The Sun Hydraulics SCIALDN (SCIALDN) is a direct-acting sequence valve with an integral reverse flow check, designed to manage flow in hydraulic systems by supplying a secondary circuit once the inlet pressure exceeds the pre-set threshold. This valve features an integral check valve allowing reverse flow from port 2 back to port 1, and it maintains pressure at port 1 relative to the drain at port 3. It is essential that port 3 is connected for accurate pressure reference; blockage may result in malfunction due to seal weepage. The valve setting is directly influenced by the pressure at port 3 on a 1:1 basis, with a maximum limit of 5000 psi (350 bar). Suitable for load-holding applications, this model incorporates Sun's floating style construction, reducing internal part binding risks due to installation torque or machining variations. The SCIALDN cartridge is compatible with EPDM seals for phosphate ester fluid systems but should avoid petroleum-based substances which can damage seals. It features a cavity size T-19A and Series 4 capacity supporting up to 120 gpm (480 L/min), and operates efficiently under pressures up to 5000 psi (350 bar) with typical response times of approximately 2 ms. The maximum allowable leakage at reseat stands at ten drops per minute or 0.7 cc/min, while its check cracking pressure is set at 25 psi (1.7 bar). Adjustments are made via clockwise turns of the adjustment screw, with specific dimensions provided for installation and maintenance purposes. The unit weighs approximately 3.10 lb (1.40 kg) and comes with a Viton seal kit option available under part number 990019006 for enhanced durability in varied operational conditions.