Engineering Bulletin

How Many BTUs Can be Handled by Corrugated Hose?

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Sometimes our customers, who are making assemblies for a heat generating system, ask if corrugated hose which they consider for an application will be able to handle a certain number of BTUs. Though it seems like unrelated question, there still should be an answer to it…

First let’s look at the definition of a BTU. BTU – stands for British Thermal Unit and – is the amount of heat energy needed to raise the temperature of one pound of water by one degree F. This is the standard measurement used to state the amount of energy that a fuel has as well as the amount of output of any heat generating device or system. All combustible materials have a BTU rating – that is amount of heat energy they produced when burned. For instance:

  • 1 cubic foot of natural gas yields about 1,030 BTU;
  • 1 pound of coal yields about 10,150 BTU;
  • 1 gallon of diesel fuel yields about 138,000 BTU;

So, if a heat generating system (working on natural gas) has rating of 8 Million BTUs/hour it means that it uses (or burns) 7,767 ft3 of natural gas in one hour (8,000,000 / 1,030); Therefore a hose used in the pipe system that supplies gas to a “burner” in such a system would have to transfer 7,767 ft3 of natural gas in one hour or – in other words – to “handle” 8 Million BTUs/hour. Such transfer corresponds to a Flow Rate of about 130 ft3/min ( 7,767 / 60 ), and the answer to the above-mentioned question comes to finding if a given Flow Rate is acceptable for the hose in question.

For maximum permissible flow rates for a given size of hose, please refer to the table below:

Maximum Permissible Flow Rates in Corrugated Hose

GAS LIQUID
Product ID Hose ID (in.) CFH
( ft3/hour)
CFM
( ft3/min.)
CFH
( ft3/hour)
CFM
( ft3/min.)
7xx-004 1/4″ 283.0 4.72 141.5 2.36
7xx-006 3/8″ 544.5 9.08 272.3 4.54
7xx-008 1/2″ 923.5 15.4 461.8 7.70
7xx-012 3/4″ 1884.0 31.4 942.0 15.70
7xx-016 1″ 3308.0 55.2 1654.0 27.6
7xx-020 1-1/4″ 5160.0 86 2580 43.0
7xx-024 1-1/2″ 8040.0 134 4020.0 67.0
7xx-032 2″ 11775.0 196.3 5887.5 98.2
7xx-048 3″ 26500.0 441.67 13250.0 221.0
7xx-064 4″ 47100.0 785.0 23400.0 390.0
7xx-080 5″ 72960.0 1216.0 36600.0 610.0
7xx-096 6″ 105000.0 1750.0 52500.0 875.0
7xx-128 8″ 180000.0 3000.0 90000.0 1500.0
7xx-160 10″ 276000.0 4600.0 138000.0 2300.0

Where the flow rates exceed those in the table, an interlocked metal hose liner or larger hose I.D. is recommended.

If you have any questions or comments, please contact us.

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