The present invention relates to a valve for providing {HEAD ~ an adjustable loss} of head by means of {TAIL ~ a mobile perforated plate} which slides over a stationary perforated plate 
The present invention relates to a valve for providing { HEAD ~ an adjustable loss } of head by means of { TAIL ~ a mobile perforated plate } which slides over a stationary perforated plate
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH