Water rotary union GP 8

for oilfor vacuumfor chemicals

Overview
The GP Series 8-passage rotary unions provide eight independent fluid passages arranged in a single rotating shaft to transfer different media simultaneously between stationary and rotating components. Standard construction is carbon steel with black oxide finish; stainless steel versions are available for corrosion resistance and for applications involving water or corrosive media. NPT models support installation via threaded passages or via O-ring face-seal glands for flush mounting; BSPP 8-passage models do not support O-ring face-seal glands. The GP Series can be integrated with standard electrical slip rings to combine fluid transfer with electrical power, signal or data.

Key Features

• Eight independent flow passages (8-passage configuration)
• Sealing technology suitable for vacuum and bidirectional pressures
• Standard carbon steel housing and shaft (black oxide); stainless steel options available
• Available with NPT or BSPP connections; NPT models compatible with O-ring face-seal glands for flush mounting
• Designed for integration with electrical slip rings for combined fluid/electrical solutions
• Custom modifications and assemblies available on request

Available Configurations (representative table)
Part # | Connection | Passage Size | Diameter | Length | Through Bore | Min. Torque (zero pressure, Oil/Hydraulic)
GP-180 | 1/8"-27 NPT (G1/8"-28 BSPP) | 0.156" [3.962 mm] | 3.437" [87.3 mm] | 7.488" [190.196 mm] | None | 10.4 ft-lbs [14.1 Nm]
GP-280 | 1/4"-18 NPT (G1/4"-19 BSPP) | 0.250" [6.35 mm] | 4.250" [107.95 mm] | 9.609" [244.069 mm] | None | 15.4 ft-lbs [20.88 Nm]
GP-380 | 3/8"-18 NPT (G3/8"-19 BSPP) | 0.375" [9.525 mm] | 4.937" [125.4 mm] | 10.000" [254.001 mm] | None | 26.4 ft-lbs [35.79 Nm]
GP-480 | 1/2"-14 NPT (G1/2"-14 BSPP) | 0.500" [12.7 mm] | 5.625" [142.875 mm] | 10.000" [254.001 mm] | None | 32.5 ft-lbs [44.06 Nm]

Pressure Options (summary)
Max. Pressure → Series
200 PSI [15 BAR] → SPS, LT, SE, GP, GPS, SCS, HVH, HPS
600 PSI [40 BAR] → SPS, LT, SE, GP, GPS, HVH, HPS
5,000 PSI [345 BAR] → SE, GP, GPS, HVH, HPS
7,500 PSI [515 BAR] → SE, GP, GPS, HPS (GP Series example: 7,500 PSI)
20,000 PSI [1,375 BAR] → HPS (high pressure series)
Other → Custom solutions available

Speed Options (summary)
Max. Speed → Series
20 RPM → SPS, LT, SE, GP, GPS, SCS, HVH, HPS
50 RPM → SPS, LT, SE, GP, GPS, SCS, HPS
75 RPM → SPS, LT, SE, GP, GPS, SCS
300 RPM → SPS, LT, SE, GP, GPS, SCS
500 RPM → SPS, LT, GP, GPS, SCS
Other → Custom solutions available

Connection Types (summary)
Connection Type → Series
ASME-BPE → SCS
BSPP → SE, GP
BSPT → LT
NPT → SPS, LT, GP, GPS
SAE-ORB → SE, HVH
Medium Pressure → HPS
Other → Custom solutions available

Suitable Media

• Air / Gas
• Coolant (water-based coolants; water/glycol) — water/glycol or coolant media must contain rust inhibitors
• Oil / Hydraulic (petroleum-based oils)
• Water / Glycol (with rust inhibitors)
• Chemical / DI water / Food-grade / Other media — available via GPS, SCS or HPS series or custom options

Charts & Data
Pressure vs. torque and pressure vs. speed charts are provided for selection and sizing. Refer to factory data for application-specific torque and speed limits.

Notes
Operational life depends on rotational speed, duty cycle and application parameters. Applications near maximum speed, with continuous duty cycles, or operating above 220° F [105° C] require alternate seal materials. Water/glycol or coolant media must include rust inhibitors; oil/hydraulic media must be petroleum-based. For non-standard pressures, speeds, connections or for combined fluid/electrical assemblies, consult factory for customization.

Technical Specifications

• Series / Commercial name: GP Series
• Maximum Pressure: 7,500 PSI [515 BAR] (GP Series example)
• Maximum Speed: 500 RPM
• Maximum Vacuum: 30 HG
• Temperature Range: 0° F to 220° F [-18° C to 105° C]; higher temperatures require alternate seals
• Housing Material (standard): Carbon Steel (Black Oxide); stainless steel available
• Shaft Material (standard): Carbon Steel (Black Oxide); stainless steel options available
• Connection Types: NPT and BSPP (NPT models available with O-ring face seal gland option; BSPP 8-passage models do not support O-ring face seal glands)
• Passages: 8 independent flow passages
• Typical Part Numbers: GP-180, GP-280, GP-380, GP-480
• Suitable Media: Air/Gas, Coolant, Oil/Hydraulic, Water/Glycol (with inhibitors); chemical/food-grade via alternative series or custom options
• Integration: Designed to integrate with electrical slip rings for combined fluid and electrical/data transfer
• Custom options: Modifications, mounting options, and combined fluid/electrical assemblies available