Performance Data

Pressure and Flow Ratings

Cartridge pressure rating is based on fatigue rating per "NFPA T2.6.1". (Assurance and verification level is "90/90" for 5000 psi (350 bar) rating. Unless otherwise stated, Sun cartridges are rated to 5000 psi (350 bar) (6000 PSI [420 bar] intermittent) in US 65-45-12 (EN16482:2014/ENGJS-400-15) ductile iron, and 3000 psi (210 bar) rating in US 6061-T6 (EU 6082T651) aluminum manifolds. All Sun cartridges are designed with a 4:1 safety factor. This means the minimum burst pressure is at least four times the rated operating pressure.

Standard cartridge hex bodies are mild steel (see Cartridges: Materials of Construction) with majority having a bright zinc-plated finish. Some cartridge hex body components utilize a nickel-plated finish to enhance wear resistance of dynamic internal components.

Zinc plating on our exposed cartridge components meets "ASTM B633" utilizing Type III Trivalent colorless chromate conversion coating. Corrosion resistance meets a minimum of 12 hrs of salt spray (fog) based on standard "ASTM B117" or "ISO 9227 5% saline" salt fog tests before signs of corrosion and 24 hours before appearance of red rust.

All cartridge performance data is derived using Chevron Rando HD ISO 32 viscosity grade oil having a specific gravity of 0.85. Tests are conducted at 110° F (42° C). Leakage is often specified in units of drops per minute. For reference, when Sun uses drops as a unit of measure for leakage, 250 drops equals one cubic inch (16 cc's). The performance data provided is developed in Sun's R&D laboratory.


Sun cartridge valves go through functional testing before shipment. Tests are performed using petroleum-based hydraulic fluid with a viscosity of 125 SUS. Filtration in Sun's test stands is 3 microns with oil temperature at 110° F (42° C). Test fluid cleanliness level meets or exceeds ISO 4406 Solid Contamination Code 19/17/14.

For maximum consistency and repeatability, Sun standard set and special set pressure controls are set at the flow rates indicated:

  • Load control valves at cracking (2 in3/min. [33 cm3/min.])
  • Pressure reducing valves at zero flow (blocked control port)
  • All other valves at 4 gpm (15 L/min)
  • Customer requested nominal pressure settings are established at nominal flow rate values indicated above. Corresponding pressure value in "psi" or "bar" units of measure is stamped on a hex flat of the cartridge body. Special requests will be handled as a custom model and handled on an individual basis.

Pressure Setting Tolerances

Sun sets all standard adjustable pressure control valves within ±15 psi or ±2.5% of the target pressure, whichever is higher. Custom valves may be subject to different tolerances. Note: It is possible that wider tolerances are observed in the field due to varying operating and test conditions, gauging, and other factors.

For testing information on valves with EPDM seals, see our EPDM Seals Page.