VSIM question (OYPH)

Glenn Harrison

Who makes that valve you pictured? That's a really nice looking valve.

Glenn Harrison

Althoff Industries Inc.

Crystal Lake, Illinois

chuck shaw

Globe or ball valve

For balancing a VSIM system, which do you prefer, a globe valve or a ball valve? And, why? Just curious.

Chuck Shaw

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Steve Ebels

Chuck

The valve of choice is a globe valve. Does a better job of throttling the flow. Less restriction at low flows than a ball.

hr

Best bet

Is to use a valve built just for that application. I have used both ball and globe. But for a few extra bucks get a valve built for throttling with a flow meter. No guessing involved. This has a nice tapered valve and seat for easy, fine adjustments.

Ball valves on VS don't seem to do much until the last little bit of handle movement. Then the tinyest movement makes a big change. Real hard to be accurate. Also the ball presents a sharp edge to the fluid flow. Not ideal! Globes are better but still not a perfect flow adjuster.

hot rod

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hr

This one

came from Watts Radiant. They only offer one size, however in their catalog. ISTEC shows a better selection of sizes and flow ranges at www.istec-corp.com.

A bit of pressure drop through the valve, no doubt. Generally VSIM applications have pump head to spare

hot rod

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Glenn Harrison

Thanks, HR (nm)

Tim Doran

Valve choices

Hi Chuck,
A globe valve or circuit setter are the best options for controling an injection loop. They have good "Valve Authority". This means that the relationship of flow to the valves position is close to equal. A ball valve on the other hand has poor authority which means that it must be closed very far to effect the flow at all and it is not in equal proportions. Hope this helps.

Tim D.