View Full Version : Air distribution restriction question...

05-23-2011, 09:16 AM
So we're setting up our air distribution using 1/2" polyurethane tubing and push fittings- the stuff is super easy to work and re-work btw.

I wanted to put a few in line shut-off valves in strategic places so I could work on the system, or shut part down without having to take everything down, but I'm looking at my 1/2" push valves and I see they reduce to less than 1/4" at the ball. I'm not a genius, that is a pretty drastic restriction imo.

Even though my distribution is set up in a loop- with 2 directions for air to flow for maximum volume I'm thinking these valves are really killing the whole reason for having 1/2" line in the first place- or am I wrong? Advise?

Thanks -Rob

05-23-2011, 10:46 AM
though some will disagree with me on this one, you are better to UPSIZE your shutoff valve rather than DOWNSIZE. So step the 1/2 ID up to 3/4" id and use that ball valve. One step usually is enough for the amount of volume that can be used in a 1/2 inch supply system...

Another thought... depending on how many props you animate, as well as how MUCH AIR they take, you may end up wanting to use a reserve tank AFTER the ball valve setup anyways. This will allow maximum volume to be delivered quickly, without the air having to travel through that 1/2 line, through the ball valve, then continue through that line to the prop(s)

Whenever I do my home haunt setup... I use three reserve tanks... this allows a great deal of VOLUME quickly.

05-23-2011, 01:39 PM
Well, changing to a different/larger ball valve was already plan B. I'm just damn surprised the valve is THAT restrictive. Guess this info may help someone else down the line. Thanks for the input.


05-23-2011, 02:04 PM
Again, it's ALL in what you want to do with it... You would need to be alot more specific for us to be able to determine if it is worth the upsize or not... Cylinder stroke, bore, quantity, times actuated per minute, etc...

The key here is VOLUME. You will always have the PRESSURE on the line, but if the VOLUME can't keep up with the pressure, then you WILL have a restriction, and that leaves the possibility of your animatronics not firing consistently, etc...

Also, I am SURE you already know this, but be SURE to have line filters for moisture and debris. Saves your valves and your cylinders from premature wear.