155-000-152 Rotary Union 1/2" BSP LH: International Buyer's Guide [2026]
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The 155-000-152 rotary union with 1/2" BSP LH thread is a left-hand-threaded rotary joint that lets pressurised media flow into a rotating shaft or drum without leakage. It is specified by its 1/2" BSP LH port, media compatibility and pressure/speed limits, and is commonly used on printing, packaging and machine-tool spindles.
What is a 155-000-152 rotary union 1/2" BSP LH?
A rotary union (also called a rotary joint or swivel joint) is a mechanical device that transfers fluid or gas from a stationary source into a rotating component while maintaining a seal. The 155-000-152 designation identifies a specific body size and seal configuration; the 1/2" BSP LH suffix defines the port thread as British Standard Pipe, left-hand.
Left-hand threads are used where rotation would otherwise loosen a right-hand fitting — typically on shafts that turn counter-clockwise when viewed from the connection end. Always verify rotation direction before ordering, because a LH union will not seal correctly on a RH-threaded shaft.
How does a rotary union work?
Inside the housing, a spring-loaded seal face bears against a rotating seal seat. Media enters through the stationary port, passes through the seal interface and exits into the rotating shaft. Bearings or a balanced seal design keep the faces aligned as speed and pressure rise.
Seal material selection (often carbon/graphite against silicon carbide or tungsten carbide) determines media compatibility and service life. For water and coolant, standard carbon seals are typical; for steam or aggressive fluids, higher-grade faces are required.
Specification table: 155-000-152 rotary union 1/2" BSP LH
| Parameter | Typical value | Notes |
|---|---|---|
| Port thread | 1/2" BSP LH | Left-hand; verify shaft rotation |
| Nominal bore | DN15 (1/2") | Matches 1/2" pipework |
| Media | Air, water, oil, coolant | Confirm with seal data |
| Max pressure | Up to 10 bar (water) | Derate for steam/air |
| Max speed | Up to 3,000 rpm | Depends on seal face |
| Max temperature | Up to 120 °C | Standard carbon seal |
| Body material | Brass or stainless steel | Stainless for corrosive media |
Values above are typical for this size class; always confirm against the OEM datasheet for the exact 155-000-152 variant supplied.
Which rotary union type suits your application?
Single-passage unions (like the 155-000-152) handle one media circuit. Multi-passage unions handle several fluids or a supply/return pair on the same shaft. For high-speed spindles, balanced mechanical seals are preferred; for low-speed drums, a simple lip or O-ring seal may suffice.
In International markets, buyers often specify stainless-steel bodies for food, pharma and marine environments, and brass for general water/coolant service. Cross-market voltage/frequency variants matter for any monitoring sensors fitted alongside the union — confirm 50 Hz or 60 Hz supply for tachometers or flow switches.
Selection criteria: how to choose a rotary union
- Thread and rotation: confirm 1/2" BSP LH and the shaft's direction of rotation.
- Media: water, air, oil, coolant or steam — this drives seal and body material.
- Pressure and temperature: check continuous ratings, not just peaks.
- Speed: match the union's rpm limit to the shaft speed.
- Environment: washdown, corrosive or outdoor service may require stainless steel.
- Duty cycle: continuous operation needs a balanced seal and robust bearings.
Product selection ladder: related tooling from 3G Electric
Rotary unions are often serviced alongside heavy fastening tooling. The table below compares impact-rated adapters and extensions from WRIGHT TOOL and PROTO that support maintenance of rotating equipment.
| Model | Type | Drive size | Output | Best for |
|---|---|---|---|---|
| PROTO 1-1/2" Drive Impact Socket Extension | Extension | 1-1/2" | 1-1/2" | Standard reach |
| WRIGHT TOOL 1-1/2" Drive Impact Socket Extension | Extension | 1-1/2" | 1-1/2" | Standard reach, black oxide |
| WRIGHT TOOL 1-1/2" to 1" Impact Socket Adapter | Adapter | 1-1/2" | 1" | Step-down drive |
| WRIGHT TOOL 1-1/2" Flex Impact Socket Adapter | Flex adapter | 1-1/2" | Square | Angled access |
| WRIGHT TOOL 15" Impact Socket Extension | Long extension | 1-1/2" | 1" | Deep reach |
Step up to the flex adapter or long extension when fasteners sit at an angle or deep inside a housing. For standard bolting, the shorter extensions keep torque transfer efficient.
Why source the 155-000-152 rotary union from 3G Electric?
3G Electric supplies industrial equipment across 14 departments — from combustion and pumps to controls, pneumatics and tooling — and we interpret your demand to deliver the right part, not just a catalogue number. With 35+ years of experience, we support International buyers with export documentation, incoterms-neutral supply and cross-market voltage/frequency variants.
We are a distributor and supplier, not an authorised dealer for every brand; we are curated and accountable, and we will tell you when a part is not the right fit. Specialist depth in pumps, combustion and controls means we can size a rotary union against your pump or burner circuit, not in isolation.
According to the British Standards Institution, BS 2779 (ISO 228) defines parallel pipe threads including BSP; left-hand variants are marked LH to prevent mis-assembly.
Frequently asked questions
What does LH mean on a 1/2" BSP rotary union? LH means left-hand thread: it tightens counter-clockwise. It is used on shafts that rotate in the direction that would loosen a right-hand fitting. Always confirm shaft rotation before ordering, because a LH union will not seal correctly on a RH-threaded shaft.
How do I select a rotary union for water service? Match the 1/2" BSP LH port to your pipework, confirm continuous pressure (typically up to 10 bar for water) and temperature (up to 120 °C with a standard carbon seal), and choose a brass or stainless body depending on corrosion risk. Check the rpm limit against shaft speed.
Where can I buy the 155-000-152 rotary union in International markets? 3G Electric supplies the 155-000-152 rotary union and related tooling to International buyers with export documentation and incoterms-neutral quotes in USD. Contact us with your media, pressure and speed data for a sized recommendation and lead time.
What is the difference between a rotary union and a swivel joint? A rotary union is designed for continuous rotation with a mechanical seal, while a swivel joint typically allows limited rotation or oscillation. For continuous shaft service, specify a rotary union with a balanced seal and rated rpm.
Do you supply 50 Hz and 60 Hz variants for International buyers? Yes — where a rotary union is supplied with monitoring sensors or adjacent controls, we confirm 50 Hz or 60 Hz supply and cross-market voltage variants so the assembly works in your region. State your supply frequency at enquiry.
Key takeaways
- The 155-000-152 is a 1/2" BSP LH rotary union for air, water, oil or coolant.
- Verify left-hand rotation before ordering — a RH union will not seal.
- Specify by media, pressure (up to 10 bar), temperature (up to 120 °C) and speed (up to 3,000 rpm).
- 3G Electric supports International buyers with export documentation and USD quotes.
Contact 3G Electric for quotes, sizing assistance and technical support on the 155-000-152 rotary union and related WRIGHT TOOL and PROTO tooling.
