SpudFiles

Hi, I was looking at the pneumatic showcase, and noticed some people are using QEVs.....and they mostly got them at mcmasters....I tried looking them up on mcmaster buuuut when you look up QEVs it says they dont anything thing by that name so what do you guys search for when your looking for one? annnnd what are the advantages of a QEV, and are they better than a sprinkler valve? easier to use?

You have to seach by the page number(I think its the page number) e.g 914

Edit: Refer to Pimp's reply below.

Apparently McMaster's search function is not fluent in the acronym "QEV", so instead you should search "Quick Exhaust Valve". Using this search term you will yield several pages of results. In the result there is 4 pages, in 3 different categories:

• Pop-Safety Valves
  Adjustable Relief Valves & Rupture Discs
  Compressed Air Flow Control Valves

The last category is the obvious choice, although a tad wordy. Now click the page number "941". Since McMaster's catalog style pages are aided by product images, finding the valve you want is easy. That which is found under the sub-heading "Quick-Exhaust Valves", and a "Right-Angle" version. In this there is 6 items that meet the criteria, all of varying port sizes.

Also for reasons unknown to me, McMaster's site does not create unique addresses when different pages are accessed. So in turn if you are to reference someone to a specific area or item, use search terms, page numbers, or product numbers. For instance:

• - Quick Exhaust Valve
  [Search term]
  
  - 941
  [QEV Page #]
  
  - 6646K23
  [Product Number - Quick Exhaust Air Valve: 3/4" Inlet, 3/4" Cylinder/Outlet, 3/4" Exhaust]

Hope to be of some assistance.

Thank you very much!

Yeah what is the advatage of a QEV compared to an average moded sprinkler valve.

A wicked increase and power! And you don't have to modify them in any way... The only downside is that they are a tad pricey. Look for 'em on eBay!

A QEV can be either a diaphragm or piston model.

Piston QEV's in my opinion are better than diaphragm ones.

For a diaphragm QEV to have the same flow as a piston it needs a large rubber diaphragm to allow for the flex needed to provide the same flow as a piston.

The pistons by the way are are a thin, moulded rubbery plastic shape - a far cry from solid pistons - both QEV types are designed to react very fast.

I won't pretend to know any exact numbers but it's said that QEV's of similar porting to sprinklers have better flow and opening speeds.

They certainly do. I recall seeing somewhere some data where a 1/2" QEV resoundingly defeated a modded 3/4" sprinkler for power, by a significant 25% increase in muzzle energy.

That's a smaller valve, and a lot more power.

A 3/4" QEV against a 3/4" sprinkler would be an even larger victory.

If you can find a 1.5" QEV cheaply, then get it. You're looking at a lot of power there.