HCV-RL-040-350-028 Relief Valve — HCIC
HCV-RL-040-350-028 is an HCIC pressure control / relief with a published rated flow of 40 L/min, a maximum operating pressure of 350 bar, and a Subplate / ISO 4401 interface. It carries PARKER RM as its cross-reference number and is used primarily for pump outlet and main system pressure limiting. Comparison figures are drawn from published technical literature and labelled with their data grade.
Cross number & interchangeability
| Product brand | HCIC |
|---|---|
| HCIC model / part number | HCV-RL-040-350-028 |
| Cross number (replaceable reference) | PARKER RM |
| Cross-reference manufacturer | Parker Hannifin |
| Cross-reference model | RM |
| Cross-reference family | RM |
| Relationship | Cross reference / selection alternative — interchangeability to be verified |
| Cross-reference source | S22 — https://discover.parker.com/DCV |
Product image
Technical drawings & circuit symbol
Hydraulic circuit symbol
Outline dimensional drawing
Mounting interface / cavity
At a glance — key facts
| What is this product? | HCV-RL-040-350-028 is an HCIC pressure control / relief. |
| Which model does it cross-reference? | PARKER RM (Parker Hannifin RM) — identification only, not a certified interchange. |
| Is this an original OEM part? | No. This is an HCIC product; the referenced manufacturer name and model are used as a cross number only. |
| What is the rated flow? | 40 L/min |
| What is the maximum operating pressure? | 350 bar |
| What mounting / cavity does it use? | Subplate / ISO 4401 |
| What are the outline dimensions? | L 205 mm |
| What is it used for? | Typical applications: pump outlet and main system pressure limiting; cross-port relief on motors and cylinders; press and clamping circuit overload protection. |
| Where do the comparison figures come from? | Official series catalogue / selection table - parameters are series ratings (source S22). |
Technical specifications
| Rated / nominal flow | 40 L/min |
|---|---|
| Rated flow (US) | 11 US gpm |
| Max. operating pressure | 350 bar |
| Max. operating pressure (US) | 5076 psi |
| Mounting / interface | Subplate / ISO 4401 |
| Fluid (series typical) | Hydraulic oil per DIN 51524; water glycol on request |
| Fluid temperature (series typical) | -20 to +70 C (NBR -25 to +70 C) |
| Viscosity (series typical) | 2.8 - 400 cSt; 30 - 80 cSt recommended |
| Cleanliness target (series typical) | ISO 4406 18/16/13 |
Data grade: Official series catalogue / selection table - parameters are series ratings
Dimensions & mounting data
| L | 205 mm |
|---|---|
| W | 45 mm |
| H | 70 mm |
Mounting interface — ISO 4401:2005 subplate interface
| Pattern | 4401-03-02-0-05 |
|---|---|
| Max Port Diameter Mm | 7.5 |
| Fastening | 4 x M5, 7-10 Nm |
Envelope basis: series-typical · Interface basis: standard-interface · DOC06 - ISO 4401-03 / NG06 / CETOP 3 mounting interface coordinates
Function
Limits system pressure by opening a controlled flow path to tank once the set pressure is reached. Direct-acting versions respond quickly to pressure spikes; pilot-operated versions provide flatter pressure/flow characteristics at higher flows.
Key features
- Normally closed modulating element with a defined pressure setting range
- Standard 350 bar (5000 psi) maximum operating pressure for cartridge versions
- Direct-acting and pilot-operated variants to match response time and flow demand
- Multiple adjustment controls: screw, tamper-resistant, handknob and factory-set
- Optional electro-proportional or solenoid two-stage control for remote pressure selection
Typical applications
- Pump outlet and main system pressure limiting
- Cross-port relief on motors and cylinders
- Press and clamping circuit overload protection
- Accumulator charging and unloading circuits
- Test stands and hydraulic power units
Selection & commissioning notes
- Confirm whether the design is a 2-port or 3-port element and whether port 2 can accept full system pressure before using it in a cross-port relief circuit.
- Tank-port back pressure is additive to the pressure setting at a 1:1 ratio on most spool-type cartridges; account for it when setting the valve.
- Spool-type relief valves leak slightly and are not suitable as the sole load-holding element; use a seated or low-leakage design where holding is safety critical.
Request a quote — 48-hour turnaround
MOQ 1 piece (samples charged, sample fee not refunded against later orders); T/T 30% deposit + 70% before shipment; 18-month warranty; quotes within 48 hours; lead time 45-60 days for samples and 30-45 days for batch orders of 50+ pieces; standard and in-stock items ship faster. Designed to ISO 6020 / 6022 / 10100. Contact davidsong@mail.huachen.cc or +86 153 7619 8599.
Frequently asked questions
What is the difference between direct-acting and pilot-operated relief valves?
Direct-acting valves open the main poppet directly against a spring and react fastest to pressure spikes. Pilot-operated valves use a small pilot stage to control a balanced main stage, giving better pressure stability at high flow but a slightly slower response.
Can this valve be used for load holding?
Spool-type relief cartridges have finite internal leakage and are not intended for load holding. Use a seated pilot-operated check or counterbalance valve for safety-critical holding.
Which seal material should be selected?
Buna-N suits standard mineral hydraulic oil. EPDM is required for phosphate-ester fluids and must not be exposed to petroleum-based oil, while Viton offers a wider temperature range.
Is HCV-RL-040-350-028 a genuine Parker Hannifin part?
No. HCV-RL-040-350-028 is an HCIC product. Parker Hannifin RM is provided only as a cross-reference number for identification. HCIC is not affiliated with, endorsed by, or an authorised distributor of Parker Hannifin. Verify all dimensions, ratings and settings before any substitution.
Can HCV-RL-040-350-028 be used in place of PARKER RM?
It is listed as a cross reference, not a certified drop-in replacement. Compare the cavity or mounting pattern, rated flow, maximum pressure, pilot ratio or spool function, seal material and pressure setting with the installed unit, and confirm with an HCIC engineer before ordering. Refer to the dimensions and interface drawings on this page.
Provenance & data quality
HCIC model: HCV-RL-040-350-028 · Brand: HCIC · Cross number: PARKER RM (Parker Hannifin RM, RM family — identification reference only)
Source ID: S22 · Source type: manufacturer · Date modified: 2026-11-13
Data grade: Official series catalogue / selection table - parameters are series ratings
Authoritative source: https://discover.parker.com/DCV