LOFB8DV – Sun Hydraulics Vent-to-open, spring-biased closed, unbalanced poppet logic element with pilot source from port 2 and integral T-8A control cavity, Viton seals
Part number: LOFB8DN · LOFB8-DN · LOFB8 DN
Vent-to-open, spring-biased closed, unbalanced poppet logic element with pilot source from port 2 and integral T-8A control cavity. Cavity T-2A, capacity 50 gpm (200 L/min.). Genuine Sun Hydraulics cartridge — MultiFlow is an authorized distributor.
LOFB8-DN overview
LOFB8DN (LOFB8-DN, LOFB8 DN) is a Sun Hydraulics Sun Hydraulics Vent-to-open, spring-biased closed, unbalanced poppet logic element with pilot source from port 2 and integral T-8A control cavity, rated 50 gpm (200 L/min.) and installed in cavity T-2A. 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.
| LOFB8DN | Buna-N sealsBuna-N |
|---|---|
| LOFB8DV | Viton sealsViton |
Specifications
| Cavity | T-2A |
|---|---|
| Series | 2 |
| Capacity | 50 gpm (200 L/min.) |
| Maximum Operating Pressure | 5000 psi (350 bar) |
| Pilot Volume Displacement | .07 in³ (1,1 cc) |
| Area Ratio, A3 to A1 | 1.8:1 |
| Area Ratio, A3 to A2 | 2.25:1 |
| Pilot Control Cavity | T-8A |
| Control Orifice Diameter | .021 in. (0,53 mm) |
| Valve Hex Size | 1 1/8 in. (28,6 mm) |
| Valve Installation Torque | 45 - 50 lbf ft (61 - 68 Nm) |
| Seal kit - Cartridge | Viton: 990202006 |
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 LOFB8DN
Sun part numbers are the model followed by one code per option. Hyphens, slashes and spaces are only dividers, so LOFB8DN, LOFB8-DN, LOFB8 DN are the same part.
| Model | LOFB8 — Sun Hydraulics Vent-to-open, spring-biased closed, unbalanced poppet logic element with pilot source from port 2 and integral T-8A control cavity |
|---|---|
| Cracking Pressure | D — 50 psi (3,5 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. |
Cracking Pressure options
- D — 50 psi (3,5 bar)
Seal Material options
- N — Buna-N
- V — Viton
Manifold & standard assemblies
Sun manifolds for cavity T-2A (544)
- 3BC Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BC — request assembly
- 3BD Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BD — request assembly
- 3BK Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BK — request assembly
- 3BL Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BL — request assembly
- 3BV Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BV — request assembly
- 3BW Sun Hydraulics Cushion lock with shuttle Line mount manifoldLOFB8DV-3BW — request assembly
- 4BC Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BC — request assembly
- 4BD Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BD — request assembly
- 4BK Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BK — request assembly
- 4BL Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BL — request assembly
- 4BV Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BV — request assembly
- 4BW Sun Hydraulics Cushion lock with make up checks Line mount manifoldLOFB8DV-4BW — request assembly
Technical features
- These valves have positive seals between port 2 and the pilot area.
- 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 logic 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.
- These valves open quickly when vented. Time to close is difficult to predict as it is dependent on the rate of flow and the pressure drop created as it closes.
- Because these valves are unbalanced, operation is pressure dependent. Opening and closing of the poppet are functions of the force balances on three areas: Port 1 = 100%, Port 2 = 80%, and the Pilot Area = 180%.
- These valves are pressure responsive at all ports, therefore it is essential to consider all aspects of system operation through a complete cycle. Pressure changes at any one port may cause a valve to switch from a closed to an open position, or vice versa. All possible pressure changes in the complete circuit must be considered to assure a safe, functional system design.
- All ports will accept 5000 psi (350 bar).
- 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
CAD files
Frequently asked questions
Is LOFB8DN the same as LOFB8-DN?
Yes. Sun Hydraulics writes this part number as LOFB8DN. It is the model LOFB8 followed by the configuration code; hyphens, slashes and spaces are only dividers, so LOFB8DN, LOFB8-DN, LOFB8 DN all refer to the same product.
Do you supply LOFB8DN in the UAE, GCC and India?
Yes. MultiFlow supplies genuine Sun Hydraulics cartridges, including LOFB8DN, 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.
I need to discharge a large accumulator. How can I increase the capacity of my discharge circuit?
Because of the very high ratio, the COFO has limited capacity. The discharge path is across a .050 inch (1,3 mm) diameter orifice. If you have large accumulators combined with low precharge pressures, this may not discharge the energy quickly enough. Using the COFO XDN cartridge in conjunction with an LODA XDN will provide capacity for larger applications.
How big is a drop of hydraulic oil?
There are exactly 250 Sun drops in a cubic inch or 15 in a cc.
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.
What parts of the Sun cartridge valve are field serviceable?
Manufacturer reference: https://www.sunhydraulics.com/model/LOFB8
