In my very small setup I have a couple of 6" gate valves situated at both ends 
of the pipe, as proposed.In addition to Robert's cautionary notes I would also 
remind you to have a adequately-sized vacuum release/surge tank just behind the 
penstock valve in case that is ever closed before the turbine one is.

Rob





Quoting [EMAIL PROTECTED]:

> 
> 
> 
> 
> Himani,
> 
>  
> 
> It might be best to have two valves, one at the top of the penstock for� 
> 
> isolation and one at the bottom for the control that you mention. It is�
> difficult 
> 
> and extremely unwise to try and control from the valve at the top of� the 
> 
> penstock, like trying to push a string. The likely scenario would be to� 
> 
> partially drain the penstock and then open the valve at the top. When the
> water� 
> 
> columns collide you will develop a water hammer such as you have never seen
> and� 
> 
> don't want to see. If you don't have enough money for two valves go with a� 
> 
> single valve at the bottom of the penstock. S l o w l y is operating rule
> number� 
> 
> 1, avoid shutting the valve down too rapidly. Some of my big penstocks
> require 
> 
>  1/2 hour to make a major rate change. Your small Hydro is a bit more 
> 
> forgiving� but the same physics apply.� Good luck.
> 
>  
> 
> Bob
> 
>  
> 
> Robert K. Weir P.E.
> 
> Hydroscreen CO.
> 
> _www.hydroscreen.com_ (http://www.hydroscreen.com) 
> 
> 
> 
> 
> 
> [Non-text portions of this message have been removed]
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Does your company feature in the microhydro business directory at
> http://microhydropower.net/directory ? If not, please register free of charge
> and be exposed to the microhydro community world wide!
> 
> 
> 
> NOTE: The advertisements in this email are added by Yahoogroups who provides
> us with free email group services. The microhydro-group does not endorse
> products or support the advertisements in any way. 
> 
> 
> 
> More information on micro hydropower at http://microhydropower.net
> 
> 
> 
> To unsubscribe: send empty message to [EMAIL PROTECTED]
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Yahoo! Groups Links
> 
> 
> To visit your group on the web, go to:
> http://groups.yahoo.com/group/microhydro/
> �
> To unsubscribe from this group, send an email to:
> [EMAIL PROTECTED]
> �
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 








------------------------ Yahoo! Groups Sponsor --------------------~--> 
Has someone you know been affected by illness or disease?
Network for Good is THE place to support health awareness efforts!
http://us.click.yahoo.com/RzSHvD/UOnJAA/79vVAA/FGYolB/TM
--------------------------------------------------------------------~-> 

Does your company feature in the microhydro business directory at 
http://microhydropower.net/directory ? If not, please register free of charge 
and be exposed to the microhydro community world wide!

NOTE: The advertisements in this email are added by Yahoogroups who provides us 
with free email group services. The microhydro-group does not endorse products 
or support the advertisements in any way. 

More information on micro hydropower at http://microhydropower.net

To unsubscribe: send empty message to [EMAIL PROTECTED] 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/microhydro/

<*> To unsubscribe from this group, send an email to:
    [EMAIL PROTECTED]

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/
 


Reply via email to