Sun Hydraulics Cavity Plugs
Sun Hydraulics cavity plugs allow a cartridge valve to be removed from its cavity while keeping the hydraulic circuit sealed and functional. This is useful when a system needs flushing after a repair, when a component is being replaced, or when a circuit’s function needs to change without machining a new manifold.
The range covers nine cavity series: Z, P, 0, 0C, 1, 1C, 2, 3 and 4, from the compact 3/8-24 UNF Series Z cavity up to the M48 Series 4 cavity, spanning two-port through to six-port configurations. This means a plug is available for virtually every cavity in Sun’s screw-in cartridge range.
Two basic plug styles are offered: plugs that block all ports, sealing the cavity completely, and plugs that keep ports open so flow continues to route through the cavity as though the cartridge valve were still fitted. Depending on the cavity, open-flow options include full flow-through (all ports connected), a single port opened to an external SAE port with the others blocked, or specific port-to-port routing, for example ports 1 and 2 connected with port 3 blocked. Flush-mount versions are also available for some two- and three-port cavities.
Standard construction uses Buna-N seals, with EPDM and Viton available on many models; EPDM is for compatibility with phosphate ester fluids. Corrosion-resistant plugs (suffix /AP) use stainless steel bodies for harsh environments, and a mild steel, zinc-nickel-plated option (suffix /LH) is available on some models.
Maximum operating pressure is 5000 psi (345 bar) across most of the range, though a small number of models, mainly larger Series 4 open-flow and dual-path plugs, are rated to 3000 psi.
Sun Hydraulics Cavity Plugs: Key Specifications, by Cavity Series
| Series | Cartridge Thread | Valve Hex Size | Installation Torque | Port Options |
|---|---|---|---|---|
| Z | 3/8-24 UNF | 5 mm | 11–14 Nm | 3-port |
| P | M16 | 22.2 mm | 27–33 Nm | 2-port, 2-port (deep), 3-port |
| 0 | M16 | 19.1 / 25.4 mm | 27–33 Nm | 2-port, 2-port (deep), 3-port (x2), 4-port (x2) |
| 0C | 3/4-16 UNF | 22.2 mm | 19–22 lbf ft | 2-port, 3-port, 4-port (common cavities) |
| 1 | M20 | 22.2 mm | 41–47 Nm | 2-port (x2), 3-port, 4-port (x2), 6-port |
| 1C | 7/8-14 UNF | 1 1/16 in / 25.4 mm | 31–35 Nm | 2-port, 3-port, 4-port, 5-port (common cavities) |
| 2 | 1″-14 UNS | 28.6 mm | 61–68 Nm | 2-port (x2), 3-port, 4-port (x2), 4-port dual path, 6-port (x2) |
| 3 | M36 | 31.8 mm | 203–217 Nm | 2-port, 3-port, 4-port (x2), 4-port dual path, 6-port (x2) |
| 4 | M48 | 41.3 mm | 474–508 Nm | 2-port, 2-port (undercut), 3-port, 3-port (undercut), 4-port (x3), 4-port dual path, 6-port (x2) |
“(x2)” etc. indicates more than one cavity of that port count within the series, each with its own dedicated plug model.
The 0C and 1C series use a common cavity design: a standardised cavity geometry shared across multiple cartridge valve manufacturers, as distinct from Sun’s proprietary cavity dimensions used in the 0, 1, 2, 3 and 4 series.
Features and Benefits
- Maintains circuit integrity while a cartridge valve is removed for service, flushing or reconfiguration
- Available across all Sun cavity series and sizes, for compatibility with virtually all of the full Sun cartridge range
- Multiple flow-path options per cavity, including all-ports-blocked, all-ports-open, and specific port-to-port routing, so a single manifold cavity can serve different circuit requirements simply by changing the plug
- Corrosion-resistant stainless steel construction is available for harsh or corrosive environments
- EPDM seal option for compatibility with phosphate ester fluids
Downloads
The following download is available from Sun Hydraulics:
Contact Us for further technical details and configuration options.