NWHIS-HEATER

Supported Applications

The Omega NWHIS series comprises circulation heaters engineered for pure water (demineralized or de-ionized) and mildly corrosive solutions with a pH range of 5 to 9. The broader product family, which includes the related NWHOIS and NWHMTSS series, extends capability to highly corrosive solutions, sulfur-laden oils, steam superheating, and high-temperature gas applications.

These units are designed for circulation systems requiring passivated stainless steel pipe bodies and INCOLOY sheath elements. The heaters support outlet gas temperatures up to nearly 1400°F in air, gas, or steam superheating configurations.

Operating Conditions & Performance

The NWHIS series operates with power ratings ranging from 6 kW to 200 kW. Electrical supply options include 120V, 240V, and 480V in both single-phase (1-Phase) and three-phase (3-Phase) configurations. Specific model variants support circuit arrangements such as "1-3" or "2-3" depending on the kW rating.

Process connections for the NWHIS series feature a 1" NPT Pipe Inlet and Outlet. The construction utilizes Type 304 Stainless Steel (ASTM A312 ERW) for pipe bodies and nozzles, with end disks made of Type 304 Stainless Steel (ASTM A240 or A479). Sheath elements are constructed from INCOLOY.

Terminal enclosures provide electrical isolation between terminals and the grounded metal sheath. Wiring terminals are spaced for proper arcing and creepage clearances per NEC standards, utilizing heavy-duty jumper straps to assure tight connections.

Configuration Options

The series offers configurable terminal enclosure ratings tailored to environmental requirements:

• E1: General Purpose
• E2: Moisture Resistant/Explosion Resistant
• E3: Explosion Resistant
• E4: Moisture Resistant

Control options available for the series include integral thermostats (60 - 250°F), mechanical AR thermostats (for E2/E3 and E4 units), thermocouple sensors, electronic PID temperature controls, SCR power panels, and integral or remote-mounted control panels with solid-state controllers.

Model numbering follows the format NWHIS-<Series Code>-<kW Code>-<Terminal Enclosure Code>/<Voltage Code>. Series codes denote element configuration (e.g., "03" for Three elements), while kW codes specify power output. Dimensions vary by model, with specific A, B, and C measurements provided in the specification tables.

Key Product Differences

The Omega circulation heater family includes three distinct series differentiated by media compatibility and construction:

• NWHMTSS Series: Designed for screw plug or flanged designs with a 1" Pipe Inlet and 3/8" NPT Pipe Plug. Power ratings range from 3 kW to 18 kW.
• NWHIS Series: Configured for pure water and mildly corrosive solutions (pH 5–9). Features 1" NPT Pipe Inlet and Outlet connections with power ratings up to 200 kW.
• NWHOIS Series: Intended for highly corrosive solutions, oils, and steam superheating. Power ratings range from 2 kW to 30 kW in the documented tables.

Note: For E2 Enclosure units on NWHMTSS-03 models, add 2" to dimension A. Side-mounted controls or control panels for NWHIS and NWHOIS series require reference to the Controls section online.