Flanged Inline

– Flanged Inline Air Heater –


The OSRAM SYLVANIA Flanged Inline Heater is an ultra-compact and robust industrial electric heat source for heating high pressure (150psi (10 BAR) max), high volume air or inert gases to 1400°F (760°C). The Flanged Inline Heater is available in 4” (36kW), 6” (72kW), or 8” (192kW or 144kW) diameter pipe sizes, and power ratings, and is supported by 2 x ANSI standard 300lb flanges. The Flanged Inline Heater uses SYLVANIA’s Patented SureHeatTM technology, which uses four internal “K” type thermocouple sensors to measure element wire temperature and inlet air temperature. These sensors work in conjunction with an external limit control (Part No. 073262) to protect the heater coils from premature failure if the airflow is suddenly reduced, or the temperature set point is accidentally turned up too high. If operated correctly, the heater will operate continuously for 5000 hours or longer. A closed-loop Flanged Inline heater system requires four components:

A) Flanged Inline Heater
B) PID-Based digital temperature controller
C) Phase-angle fired SCR power controller
D) 4 input Overtemperature limit circuit
The control components must be purchased separately, and mounted inside a wellventilated electrical cabinet by qualified personnel. OSRAM SYLVANIA provides the following control components which are guaranteed to work with our heater. Use of other control devices are not guaranteed by OSRAM SYLVANIA and could result in shortened heater life and/or immediate heater failure. NOTE: P/N 073262 (4-input Temperature Limit Circuit) is an integral and critical part of the system, and MUST be purchased from OSRAM SYLVANIA. It cannot be substituted with other “temperature limit devices” under any circumstances.



An OSRAM SYLVANIA Specialty Flanged Inline (SFI) system consists of three (3) major components. See block diagram below. Inline Heater (either HP or LP design) Control Cabinet SureHeat® Flow Sensing System (FSS)**SureHeat® FSS is not offered for heater sizes < 2.5” diameter.


Customer is required to provide interconnect wire between:

  • Mains Supply (380V/480V-3PH) and Control Cabinet (as appropriate)
  • Control Cabinet (380V/480V-3PH) and Heater (as appropriate)
  • Heater KTC probes and Control Cabinet (K type – Chromel/Alumel)
  • Heater Flow Sensor KTC’s and Control Cabinet (K type – Chromel/Alumel)
  • Flow Sensor Coil and Control Cabinet (5VDC) (16 AWG copper)

System Overview

An OSRAM Specialty Flanged Inline (SFI) system consists of two (2) major components. See
block diagram below.

  • Inline Heater (either HP or LP design)
  • Control Cabinet


There are two heater types:

SFI-HP (high pressure) models (LEFT image below) are designed for use with high pressure air sources (> 50 psi), and are constructed of heating elements aligned with the airflow. SFI-HP models can produce air/gas temperatures to 1400°F or higher.

SFI-LP (low pressure) models (RIGHT image below) are designed for use with low pressure air sources like regenerative blowers (< 50 psi) and are constructed of low-restriction crossflow elements. SFI-LP models can produce air/gas temperatures to 1200°F.


OSRAM’s SureHeat® Over-Temperature Protection System (OTP), uses Type K thermocouple device(s) to monitor the wire temperature of the heater and through the SureHeat® OTP control circuit the power going to heater is reduced in the event the design temperature of the heating elements are being approached upon. (Please note not all heaters include this Added features)


(Reference) Installation Instructions:
This section serves a general guide. Specific installation detail is distributed with the heater drawings and should be followed by default. (Note all mounting hardware is included with sensor when included)

1. Assemble the SureHeat® OTP Sensor to the Bracket using the (3) M5 x 12mm
Slotted Screws and (3) #10 Lockwashers supplied.

2. Assemble the Bracket/OTP Assembly to the Plate located on the Housing using (4) M5 Washers, (4) #10 Lock-washers and (4) #10-32 x ½” Socket Screws. Be sure to place the Washer against the bracket then the Lockwasher and finally the Socket Screw. (Do Not Tighten).

3. Adjust the Bracket so there is a 1/16” (2mm) gap between the top of the Pre-Assembled Coupling and the bottom of the SureHeat® OTP Sensor as well as centering the Sensor over the Coupling. Tighten Socket Screws too secure assembly. (See Figure 3)

4. Attach the ¼” Air Hose to the Ferrule Located on the SureHeat® OTP Sensor.
(See Figure 3)


  • Designed for high pressure, high flow applications
  • Air/inert gas temperatures to (1400˚F) 760˚C
  • Uses SureHeat over temperature protection system
  • Up to 192kW in a compact 610mm (24″) long size
  • Maximum air pressure 10 Bar 150 (PSI)
  • 304 Stainless Steel ASME welded 300 lb. flanged housing
  • Maximum inlet temperature 482˚C (900˚F)

Built-in “K” type thermocouples