Description

The Smith 299-011-1B is a proportional two-gas mixer in the Smith/Miller 299 series, factory-configured for Argon and Hydrogen blending. This part is also referenced as the earlier revision of the current catalog number 299-011-1C, which supersedes the 299-011-1B; Miller Electric has confirmed both revisions are operationally identical with the same internal components. Refer to manufacturer documentation to confirm compatibility with your specific application.

This mechanical, non-electrical device blends two gases at infinitely variable proportions using a single mixing control knob, delivering mixing accuracy of ±2% of scale. The argon channel adjustment range is Fifty to One Hundred (50–100%) and hydrogen is Fifty to Zero (50–0%), with a delivery flow range of Ten to One Hundred Eighty (10–180) SCFH (4.8–85.7 LPM). Required inlet pressure for both gas supplies is 105–115 PSIG (7.3–7.9 bar), and the outlet pressure without flow is 50 PSIG (3.5 bar). The argon inlet connection is 5/8 in – 18 RH Internal; the hydrogen inlet uses a 9/16 in – 18 LH External fitting (left-hand thread, standard for flammable gas); the outlet connection is 5/8 in – 18 RH Internal.

With the appropriate conversion chart, the 299-011-1B can also be used to blend Argon/Helium, Argon/Oxygen, Argon/CO2, and Nitrogen/Hydrogen gas combinations. The unit incorporates its own built-in flow control, eliminating the need for separate downstream flowmeters in single-station applications. Separate upstream pressure regulators — not standard flowmeters — are required on each supply cylinder to deliver gas to the mixer at the required inlet pressure range.

Technical Specifications

• Brand: Smith (Miller Electric Mfg. LLC)
• MPN: 299-011-1B
• Superseded By: 299-011-1C
• Type: Proportional Two-Gas Mixer
• Series: 299 Standard Capacity
• Factory Gas Configuration: Argon / Hydrogen
• Compatible Gas Combinations: Argon/Hydrogen (factory), Argon/Helium, Argon/Oxygen, Argon/CO2, Nitrogen/Hydrogen (via conversion chart)
• Argon Adjustment Range: 50–100%
• Hydrogen Adjustment Range: 50–0%
• Flow Rate: 10–180 SCFH (4.8–85.7 LPM)
• Required Inlet Pressure: 105–115 PSIG (7.3–7.9 bar / 724–793 kPa)
• Outlet Pressure (No Flow): 50 PSIG (3.5 bar / 344.7 kPa)
• Mixing Accuracy: ±2% of scale
• Argon Inlet Connection: 5/8 in – 18 RH Internal
• Hydrogen Inlet Connection: 9/16 in – 18 LH External
• Outlet Connection: 5/8 in – 18 RH Internal
• Power Required: None (fully mechanical)
• Country of Manufacture: United States