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spool valves

Posted: Mon Nov 24, 2008 11:38 am
by POLAND_SPUD
hey I have one simple question...

Is it possible to actuate manualy solenoid valves like for example this one Clicky clicky

I htink I already know the answer but I asked some people and they all claim that it's not possible so I am a bit confussed... :? [/url]

Posted: Mon Nov 24, 2008 12:36 pm
by Gippeto
I think this might help. :wink:

http://www.smcusa.com/sections/products/valves.asp


Edited to fix the link. :roll:

Posted: Mon Nov 24, 2008 1:08 pm
by POLAND_SPUD
hmmm I've read quite a lot but that still does not anwser my question... is it possible to mechanically actuate a solenoid valve (with or without solenoid removed) ?

Posted: Mon Nov 24, 2008 2:38 pm
by Gippeto
I get it now.

You're not asking IF they exist, you're asking if you can convert/modify them TO mechanical activation?

The only thing I could suggest, is to contact the company and talk to someone in parts.

If they're like the parts people I deal with, they will know their product inside and out, and will be able to tell you for sure.

Posted: Mon Nov 24, 2008 3:30 pm
by iknowmy3tables
well I'm not sure about this one because I don't see it, but many electric solenoids come with a manual bleed like a button or switch that will open the valve

Posted: Tue Nov 25, 2008 8:56 am
by POLAND_SPUD
ohhh sorry for not specifying my question... yeah I meant --> is it possible to convert solenoid valves to acctuate them mechanically....?

Normally I'd ask the manufacturer but that won't help much since most valves are produced abroad and the stuff is quite expensive here... so ordering anything from them would cost a lot of $$$
asking people is not the best idea neither becasue most of the guys that deal with pneumatic stuff have no idea what they are selling or they say 'just order a manually actuated valve'... the only problem here is the price - new valves cost at least 100 - 120 zl (~ 40 - 60$)

the thing is I can get lots of dirt cheap solenoid valves from allegro.pl (it's like E-bay) but I preffer mechanical acctuation... I am more then 99% sure that the solenoid does acctuate the valve mechanically (if you've seen diagrams on http://www.smcusa.com/sections/products/valves.asp then you know what I mean)

I thought that maybe someone has done this before and he knows how to do it in the best way...

Posted: Wed Oct 14, 2009 11:21 am
by kenbo0422
Most solenoids I've seen have a valve stem that fits inside the actuating coil. When the coil is activated, it causes the stem to become an electromagnet and opens/closes the valve. Removing the coil should reveal the valve stem and all you need is to connect it mechanically to move it.

Posted: Wed Oct 14, 2009 11:44 am
by Technician1002
kenbo0422 wrote:Most solenoids I've seen have a valve stem that fits inside the actuating coil. When the coil is activated, it causes the stem to become an electromagnet and opens/closes the valve. Removing the coil should reveal the valve stem and all you need is to connect it mechanically to move it.
In some as in many sprinkler valves the moving core is in the area under pressure so removing the coil not only exposes the moving part (armature) but also vents the valve it operates. The physical coil is often wound directly onto this cylinder the armature moves inside. To mechanically move the armature inside the pressurized sealed tube without making it leak simply requires an alternate magnetic field of sufficient strength.

If the coil is removed, but the mechanical parts are left intact so no leaks are created, many of these valve can be actuated by using the ring magnet from a microwave oven magnetron or speaker. Placing a strong permanent magnet on the valve in place of the electric coil can activate many of them. Moving the coil onto and off of the valve operates it.

The simplest ones to modify are the ones that can have the coil removed to change to another voltage without compromising the valve itself. This does not include sprinkler valves as their solenoid contains the armature and seal.

Most that can have the coil removed look like these. The coil simply sits over the tube containing the armature and is held in place with a retaining clip or nut.
Image

Posted: Wed Oct 14, 2009 12:45 pm
by kenbo0422
Neodimium (sp) magnets, cheap at American Science and Surplus, and less space used, too.

Posted: Thu Oct 15, 2009 7:32 am
by jackssmirkingrevenge
I think the question has been answered;)

Posted: Thu Oct 15, 2009 12:17 pm
by POLAND_SPUD
yeah
the valve I bought has a mechanical override so I can use it without the solenoid....

but mechanical override is just an additional gizmo added to the valve to allow switching it on/off when needed so it doesn't work as reliable as the solenoid itself...
in fact the part is the reason why the valve now leaks at anything above 200 psi and/or refuses to switch... I can dissemble and fix it but after a couple of shots it might break down again...
(i'll add a link to the thread with pic of the valve so that you could see why the design makes the valve prone to leak)

I switched to using direct acting valves and manual valves in general.. I realize that indirect acting valves have faster and more consistent opening switching times but generally speaking they don't handle high pressures good...

as they say... you never stop learning... :?

EDIT
have a look here
http://www.spudfiles.com/forums/solenoi ... 16722.html

and notice that the solenoid is held shut by springs (not visible in the pics) so at a given pressure it will leak just like a blowgun attached the other way round..
probably I could replace the springs but it's not easy to find ones that are small enough, will hold the solenoid shut at high pressure and allow it to open when needed