RPGS8-WN – Sun Hydraulics Pilot-operated, balanced poppet relief main stage with integral T-8A control cavity
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Part number: RPGS8WN · RPGS8-WN · RPGS8 WN
Pilot-operated, balanced poppet relief main stage with integral T-8A control cavity. Cavity T-3A, capacity 50 gpm (200 L/min.). Genuine Sun Hydraulics cartridge — MultiFlow is an authorized distributor.
RPGS8-WN overview
RPGS8WN (RPGS8-WN, RPGS8 WN) is a Sun Hydraulics Sun Hydraulics Pilot-operated, balanced poppet relief main stage with integral T-8A control cavity, rated 50 gpm (200 L/min.) and installed in cavity T-3A. MultiFlow supplies genuine Sun Hydraulics cartridges in the UAE, GCC and India — use Add to Enquiry above for availability and a quotation.
Ordering codes
Pick the code that matches the material and finish you need. Add it to your enquiry above, or tap a code to select it.
| RPGS8WN | Buna-N sealsBuna-N |
|---|---|
| RPGS8WV | Viton sealsViton |
| RPGS8WE | EPDM sealsEPDM |
Specifications
| Cavity | T-3A |
|---|---|
| Series | 2 |
| Capacity | 50 gpm (200 L/min.) |
| Maximum Operating Pressure | 5000 psi (350 bar) |
| Control Pilot Flow | 10 - 15 in³/min. (0,16 - 0,25 L/min.) |
| Pilot Control Cavity | T-8A |
| Pilot Control Valve Installation Torque | 20 - 25 lbf ft (27 - 33 Nm) |
| Pilot Control Valve Hex Size | 7/8 in. (22,2 mm) |
| Main stage leakage at reseat | 10 drops/min. (0,7 cc/min.) |
| Response Time - Typical | 2 ms |
| Valve Hex Size | 1 1/8 in. (28,6 mm) |
| Valve Installation Torque | 45 - 50 lbf ft (61 - 68 Nm) |
| Model Weight | .50 lb (0,25 kg) |
| Seal kit - Cartridge | Viton: 990303006 |
Compound cartridge (pilot and main stage) assembly information is provided for reference only. Cartridges must be ordered separately and assembled at point of use.
How to read RPGS8WN
Sun part numbers are the model followed by one code per option. Hyphens, slashes and spaces are only dividers, so RPGS8WN, RPGS8-WN, RPGS8 WN are the same part.
| Model | RPGS8 — Sun Hydraulics Pilot-operated, balanced poppet relief main stage with integral T-8A control cavity |
|---|---|
| Adjustment Range | W — 100 - 5000 psi (7 - 350 bar) |
| Seal Material | N — Buna-N |
| Material / coating | Add /AP (stainless steel, passivated) or /LH (mild steel, zinc-nickel) to the end; no suffix is the standard finish. |
Adjustment Range options
- B — 50 - 1500 psi (3,5 - 105 bar)
- W — 100 - 5000 psi (7 - 350 bar)
Seal Material options
- N — Buna-N
- V — Viton
- E — EPDM
Manifold & standard assemblies
Sun manifolds for cavity T-3A (238)
- CA3 Sun Hydraulics Ninety degree with gauge port Line mount manifoldRPGS8WN-CA3 — request assembly
- CA4 Sun Hydraulics Ninety degree with gauge port Line mount manifoldRPGS8WN-CA4 — request assembly
- CA5 Sun Hydraulics Ninety degree with gauge port Line mount manifoldRPGS8WN-CA5 — request assembly
- CAA Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAA — request assembly
- CAB Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAB — request assembly
- CAC Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAC — request assembly
- CAD Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAD — request assembly
- CAE Sun Hydraulics Ninety degree with gauge port Line mount manifoldRPGS8WN-CAE — request assembly
- CAH Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAH — request assembly
- CAI Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAI — request assembly
- CAJ Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAJ — request assembly
- CAK Sun Hydraulics Ninety degree Line mount manifoldRPGS8WN-CAK — request assembly
Technical features
- Because the modulating occurs inside the cartridge, these valves are immune to most of the problems associated with cavitation, namely noise and manifold erosion.
- Cartridges configured with EPDM seals are for use in systems with phosphate ester fluids. Exposure to petroleum based fluids, greases and lubricants will damage the seals.
- Will accept maximum pressure at port 2; suitable for use in cross port relief circuits.
- Valve is relatively insensitive to varying oil temperatures and oil borne contamination.
- Main stage orifice is protected by a 150-micron stainless steel screen.
- Back pressure on the tank port (port 2) is directly additive to the valve setting at a 1:1 ratio.
- NOTE: With the -8 control option, the main stage valve should first be installed to the correct torque value. The T-8A pilot control valve should then be installed into the main stage valve to its required torque value.
- The -8 control option allows the pilot control valve to be incorporated directly into the end of the relief cartridge via the T-8A cavity. These pilot control cartridges are sold separately and include electro-proportional, solenoid, air pilot, and hydraulic pilot operation. See Pilot Control Cartridges.
- All 2-port relief cartridges (except pilot reliefs) are physically and functionally interchangeable (same flow path, same cavity for a given frame size).
- Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge machining variations.
Drawings, symbol & performance curves
Downloads
Datasheet
Technical reference sheets
- 999-901-334 (PDF 344 KB)
- FloatingStyleScrewInCartridge2 (PDF 1 MB)
- TT_US_Amplifier-New (PDF 2 MB)
- TT_US_Cavity-New (PDF 522 KB)
- TT_US_Electro-Prop (PDF 1 MB)
- TT_US_Relief-N (PDF 656 KB)
- TT_US_coils-New (PDF 975 KB)
- rel-Prop_terms-definitionsN (PDF 3 MB)
CAD files
Frequently asked questions
Is RPGS8WN the same as RPGS8-WN?
Yes. Sun Hydraulics writes this part number as RPGS8WN. It is the model RPGS8 followed by the configuration code; hyphens, slashes and spaces are only dividers, so RPGS8WN, RPGS8-WN, RPGS8 WN all refer to the same product.
Do you supply RPGS8WN in the UAE, GCC and India?
Yes. MultiFlow supplies genuine Sun Hydraulics cartridges, including RPGS8WN, to customers in the UAE, the wider GCC and India. Use Add to Enquiry on this page for availability, lead time and a quotation.
Can I get the datasheet and CAD files?
Yes. The datasheet, technical reference sheets and CAD files (DXF, DWG, STP) are listed in the Downloads section of this page.
Direct acting or pilot operated - what do I use?
Direct-acting valves are used to prevent over pressure, and pilot-operated valves are used to regulate pressure. If you are unsure, use a direct-acting valve. Sun's direct acting valves are very fast, dirt tolerant, stable, and robust. Sun's pilot-operated valves are moderately fast, they have a low pressure rise vs. flow curve, and they are easy to adjust.
How do I get a kick-down relief to reset?
The kick-down relief acts much like a circuit breaker. When the pressure at the inlet (port 1) of the relief valve rises to the setting, the valve pops open and drops the pressure down to 100 psi or so. The valve stays open until flow through it stops. Shutting off the supply of oil will reset the valve; reversing pressure on the valve is a positive way of resetting it.
Where would I use a kick-down relief?
One graphic example is on a portable grain auger for silos. When the farmer gets caught in the auger the kick-down relief trips and allows him to escape.
How big is a drop of hydraulic oil?
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
What are the tolerances on pressure settings for Sun's pressure control valves?
Pressure setting tolerances are listed in our Performance Data page. A link to this page can also be found in the Additional Resources tab of the applicable product page.
Can I use a kick-down relief for my system relief?
Maybe not. We build in a good amount of overlap in the kick-down reliefs to prevent false tripping. This means they are not as fast as our standard pilot-operated reliefs. A direct-acting relief valve set just above the kick-down relief valve would be good insurance.
What parts of the Sun cartridge valve are field serviceable?
Only external seals are serviceable. Sun offers replacement seal kits for all cartridge models. The applicable kit part number can be found in the product page's Technical Data table or by using our Cartridge Seal Kit search function located under Accessories. Please note: Converting the external seals from one material to another does not ensure fluid compatibility with that material due to the existence of internal seals within the cartridge.
Manufacturer reference: https://www.sunhydraulics.com/model/RPGS8
