ULVAC HELIOT 904D4R — High-Capacity Dry Roots Pump Mobile Leak Detector
The HELIOT 904D4R is the highest-capacity model in the ULVAC HELIOT 900 series. It uses a large dry Roots pump (500 L/min / 30 m³/h at 50 Hz) as its backing pump, providing maximum pump-down speed with dry (oil-free) operation. The 904D4R is designed for high-throughput production test systems, large test chambers, and applications where cycle time is limited by the pump-down phase.
Model designation confirmed from ULVAC Components Catalog Vol.11, page 56 specification table (“904D4R”).
Configuration Summary
- Form factor: Mobile cart (444×660×991 mm W×D×H)
- Backing pump: Dry Roots pump (Roots-type; largest in 900 series)
- Backing pump capacity: 500 L/min / 30 m³/h / 17.6 cfm at 50 Hz
- Pump oil required: No (gas compression path is oil-free)
- Inlet port: KF25 (NW25, ISO)
Technical Specifications
Values confirmed from ULVAC Components Catalog Vol.11, page 56.
| Parameter | Value | Notes |
|---|---|---|
| Model designation | HELIOT 904D4R | Verify against nameplate |
| Detectable gas | ⁴He (helium), H₂ (hydrogen) | Vacuum method |
| Min. detectable leak rate (⁴He) | <5×10⁻¹³ Pa·m³/s | ULTRA flow mode |
| Min. detectable leak rate (⁴He) | <5×10⁻¹² mbar·L/s | ULTRA flow mode |
| Leak rate display — ULTRA (He) | 1×10⁻¹⁴ to 1×10⁻⁶ Pa·m³/s | — |
| Leak rate display — FINE (He) | 1×10⁻¹² to 1×10⁻⁵ Pa·m³/s | — |
| Leak rate display — GROSS (He) | 1×10⁻¹° to 1×10⁻³ Pa·m³/s | — |
| Leak rate display — FINE (H₂) | 1×10⁻⁸ to 1×10⁻⁵ Pa·m³/s | — |
| Inlet pumping speed (He) — ULTRA | 5 L/s | — |
| Inlet pumping speed (He) — FINE | 1 L/s | — |
| Max. inlet pressure — ULTRA | <2 Pa | — |
| Max. inlet pressure — FINE | <100 Pa | — |
| Max. inlet pressure — GROSS | <1,200 Pa | — |
| Main TMP | 31 L/s | Turbomolecular pump |
| Backing pump type | Dry Roots pump | Roots-type dry pump; largest in 900 series |
| Backing pump capacity | 500 L/min / 30 m³/h / 17.6 cfm | At 50 Hz; highest in 900 series |
| Weight (with cart) | ~77 kg | — |
| Power consumption | 800 VA (50 Hz) / 950 VA (60 Hz) | Same as 904D3R |
| Input power | Single phase 100–120 V or 200–240 V AC | — |
| Inlet port | KF25 (NW25, ISO) | — |
| Startup time | <2 min | — |
| Dimensions W×D×H (with cart) | 444×660×991 mm | Same for all 904 models |
| Interfaces | RS-232C, RS-485, analogue DC, digital I/O | — |
| Controller | 7″ tablet, wireless IEEE 802.11 b/g/n | Standard accessory |
| Standards | CE, IP30 | — |
| Operating temperature | 10–40°C, non-condensing | — |
Why 500 L/min Backing Pump Capacity Matters
The backing pump capacity determines how fast the instrument evacuates the test object from atmospheric pressure to the inlet pressure required for ULTRA flow mode (<2 Pa). For test systems with large internal volumes — large vacuum chambers, tube bundles, manifolds, or large assemblies — the pump-down time from atmosphere to ULTRA flow is the dominant part of the test cycle time. The 904D4R’s 500 L/min backing pump is twice the capacity of the 904D3R and over three times that of the 901D2, giving proportionally faster pump-down of large volumes.
Note: The 5 L/s sensitivity of the ULTRA flow mass spectrometer analyser circuit is the same across all 900 series models — the backing pump determines pump-down speed, not ultimate test sensitivity. A smaller pump and a larger pump give the same minimum detectable leak rate once ULTRA flow pressure is reached.
Typical Applications
- High-throughput production leak test systems with large test chamber volumes
- Semiconductor process equipment maintenance testing
- Heat exchanger tube bundles (large gas volume)
- Cryogenic equipment and cryostat testing
- Large scientific instrument chambers
- Any application where pump-down time is the test cycle bottleneck
Service Enquiry
Email: mail@ulvacheliot.com
Include: model designation from nameplate (HELIOT 904D4R), serial number, fault or service required, facility location.
Repair | Preventive Maintenance | Calibration | Backing Pump Service | Spare Parts | 900 Series overview
Regional Variants and Part Numbers
| Model designation | Part number | Supply voltage | Certification | Region |
|---|---|---|---|---|
| HELIOT 904D4-F1A | 210006829800 | AC 100–120 V | PSE / UL / CSA | US / North America |
| HELIOT 904D4-F2B | 210006830300 | AC 200–240 V | PSE / UL / CSA | SE Asia |
| HELIOT 904D4-F2E | 210006831300 | AC 200–240 V | IEC | EU / international |
| HELIOT 904D4-F1Z | 210006875800 | AC 100–120 V | — | Without power supply cable |
| HELIOT 904D4-F2Z | 210006876300 | AC 200–240 V | — | Without power supply cable |