Flextech Engineering, Inc.

"Improved efficiency through improved design"
Call for recommendations or estimates: (626) 914-2494 Fax: (626) 914-1404

Fired Heater Tube Seals

The Problem

In the average size fired heater, the openings around the tubes allow thousands of cubic feet of cool air to be drawn into your heater every day with costly consequences:

1. Heating cool air ingress increases fuel costs

2. Air ingress increases NOx emissions

3. Air ingress has an adverse effect on draft, and therefore burner efficiency, and can cause flame impingement on the heater tubes.

The Solution

Flextech Tube Seals are designed to stop ALL the ingress air!

See below to calculate your potential savings using Flextech Engineering's tube seals!

Many heaters commonly utilize insulation packing, spring seals, metal covers, or simple pad wraps, as a means to keep the heat inside, but they are inefficient and often completely ineffective at sealing off the flow of air around and through them. In some cases, these "seals" block only 10% of the ingress air!

Contact Flextech Engineering, Inc. today and let us help you seal your heater!

Physical Data

The following calculations for cost of fuel consumed heating excess air are based on an actual case history for a steam methane reformer:

Area of 0.5" annular gap around 6" dia. tube A=0.071 ft2
Internal draft @ ΔP=.35" H20 ω=1.92 lbs air/sec
Internal heater temperature T=1950 deg. F
Energy required to heat ambient air ΔH=495 BTU/lb
Heating cost per million BTU's $5.00/1 X 106 BTU
Number of tubes (and tube openings) 100


Number of tubes Annular area Air draft Seconds per year Heat energy Fuel cost
100 X 0.071 ft2 X 1.92 lbs air X 31.5 x 10 sec X 495 BTU X $5.00
sec/ft2 year 1 x 106 BTU

The cost of heating the ingress air is nearly $1,000,000 PER YEAR!

Click here for a spreadsheet you can use to do your own calculations.

Contact Flextech Engineering, Inc. to calculate your potential savings with Flextech Tube Seals, or schedule a field engineer to survey your heaters.

© 2017 Flextech Engineering, Inc. All Rights Reserved.
Flextech Engineering, Inc. P.O. Box 725 Glendora, CA 91740
Phone: (626) 914-2494 Fax: (626) 914-1404