Instrument Air Tubing Length

17.3 miles.

It really depends on what pressure you need at the other end of the pipe

Best regards,

John

...and how quickly it needs to arrive.

A reference guide, 125 pages on the topic:

http://www.scribd.com/doc/12725993/23/Best-practices-for-impulse-tubing-installation

You only forgot the pesky little static details, and in particular the dynamic detailsthat matter. Care to fill in some details?

Dear All

In our plant air we have header( Tree Manifold ) from the header the air tubing we have run is max. 25Mtrs long x 12mmO.D for all vlv. regardless of size.

Regards

Wonderful.

But, for both static and dynamic response timing, factors establishing it are needed. For example a 1% static readout precision so many tau time constants (consisting of tube resistance and meter storing capability) is needed to elapse. In order to get the required precision, that is.

Many years ago, when there where no electronic instrumentation available, and tubing was used equally for instrument sensing, impulse lines, etc., the maximum distance that you could use before the line could not repeat the signal was in the order of about 60 meters (180 feet), but I do not recommend anything over 15-20 meters (45-60 Feet) since the time the tubing has to send the signal may give you a very large error.

With modern instrumentation the maximum impulse line should not be greater than 5 to 7 meters (15 - 20 Feet) this way you can remove some temperature issues and still have a quick sensing response.

Also you can play with the distance by using different sized tubing anything between 1/4" to 1", but costs will increase as size of tubing increases.