I have a 3/8 inch numatics solenoid which operates a 24 inch on/off valve. The line feeding the solenoid is 1/2 S.S. and it was suggested that installing a larger numatics solenid valve with 3/4 inch fittings will increase the volume which will help stroke the valve. If the feed line is still only 1/2 inch will the larger 3/4 inch solenoid valve body help stroking the valve or would the feed line need to be increased as well?

 

The flow through a solenoid that is controlling a valve is dependent on the Cv of orifice inside the solenoid and the orifice size is commonly not the same size as the solenoid's ports, though they are generally related, e.g. the larger the port size, the large the available orifice sizes. So a 3/4 or 1/2" inch port size solenoid will typically have a larger size orifice (Cv) than a 3/8" one. In regards to the tubing, the valve speed of response is also limited by its size (and by the connection size to the valve or any other restrictions in the exhaust line, e.g. bug screens, check valves, solenoid's flow path restriction, etc), but the solenoid orifice size, if not full port, will commonly be a determining factor. People commonly use over sized solenoids to get larger Cv's but once the orifice gets to line size (e.g. full port), other restrictions that limit the valve's response will come into play.

If you need to speed up the response of your valve, you can use a quick exhaust valve or booster. There are also quick exhaust solenoids available.

See the following links for some additional information:

http://www2.emersonprocess.com/en-U...rottlingExhaustBooster/289RC/Pages/289RC.aspx

http://www.ascovalve.com/Applicatio...4.pdf&id=8321G001AC120/60,110/50D&External=no

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Search Internet for "Versa Quick Exhaust QE"


William (Bill) L. Mostia, Jr. PE
ISA Fellow, SIS-TECH Fellow,
FS Eng. (TUV Rheinland)
SIS-TECH Solutions, LP

Any information is provided on Caveat Emptor basis.
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It will help some, especially with valves that have a lot of shape changes in the flow like many manifold valves. The idea is to get closer to the flow of the 1/2 inch line without a valve. If that isn't enough then you need a bigger line. I have seen some valves that had passages way smaller than the bore size of the fittings as manufacturers try to offer more options with less body sizes.

Regards
cww

 

Several things affect actuator speed.

Control valve Cv. Larger Cv will give you faster response up until the point the valve is no longer the limiting factor.

Proximity to the actuator. Closer is better.

Optimum line size. Larger line may help due to reduced restriction to flow, but if you use too large a line, pressurizing the line itself adds more time than the reduction in restriction saves.

Bottom line, get the control valve close enough to the actuator and the line size won't matter, then go to as big a control valve as you need to get whatever speed you need. Don't forget to be alert to restrictions on the downstream (exhaust) side, if the actuator isn't spring return. Restrictions on the exhaust side can limit speed too. That's where flow controls are typically placed to intentionally reduce actuator speed, for example.

Another option, for example if the 24" valve is in a classified area, so you don't want to locate the solenoid there, would be to put an intermediate size air-piloted valve at the 24" valve controlling it, say 1", then run a 1/4" or 3/8" line from the solenoid in it's current position out to the 1" port air-piloted valve controlling the big valve.

 

to help refine the excellent responses you have thus far, actuator type and stroke distance, air supply, filter regulator size and setting, etc., would be helpful as well as the main valve type and seating and the stroke time you are trying to satisfy.

you might look into whether the actuator was supplied with a booster relay as well....